Laser Safety Program - Glenn Research Center · 6.1.3 Other Training ... 6.9.6 NASA Laser Safety Review Board (LSRB) ... mechanisms may be employed in atypical situations.

GLP 1800.1.13 Printed copies are uncontrolled and may not reflect current information. Page 1 of 30 http://smad-ext.grc.nasa.gov/shed/pub/ohpm/ohpm-manual.pdf

. . . .

Document Number: GLP-QS-1800.1.13

Revision Revision F

Effective Date: 6/28/2017

Expiration Date: 6/28/2022

Occupational Health Programs Manual –Chapter 13

Laser Safety Program

DRAFT (Include when appropriate) Approved by: QS/Chief, Safety and Health Division Distribution: BMS Library

NASA - Glenn Research Center Cleveland, OH 44135

http://smad-ext.grc.nasa.gov/shed/pub/ohpm/ohpm-manual.pdf

Glenn Research Center Occupational Health Programs Manual

Title: Laser Safety Program Document No.: GLP-QS-1800.1.13 Rev.: F


Change Record

Revision Effective Date

Expiration Date

C-25, Change Request

#

Description

1A 3/20/2012 3/20/2017 310

Reorganization changes, satisfy additional requirements in reference work instruction on chapter content. Added additional laser safety training category. Added verification elements (gray boxes in section 6).

1 3/20/2012 3/20/2017 n/a Administrative change to add front cover and change history log to comply with NPR 1400.1.

Change 2 9/20/2012 3/20/2017 Administrative change to remove hyperlinks.

Change 3 3/20/2017 8/31/2017 N/A Administrative Change to extend the expiration date six months, due to anticipated changes to chapter.

F 6/28/2017 6/28/2022 17-015

Added NPR 8715.3 requirements and new NPR 1800.1 laser safety review board (LSRB) requirements. Removed requirement for baseline eye exam. Updated signage format and interlock requirements for multi-door facilities. Added authority having jurisdiction (AHJ) role and fire hazard evaluation requirements. Added 2 informational, non-normative appendices. Removed verification elements (gray boxes).

**Include all information for each revision. Do not remove old revision data. Add new rows to table when space runs out by pressing the tab key in the last row, far right column.





Contents 1.0 PURPOSE ............................................................................................................................................................ 5 2.0 APPLICABILITY ................................................................................................................................................ 5 3.0 BACKGROUND.................................................................................................................................................. 5 4.0 POLICY ............................................................................................................................................................... 6 5.0 RESPONSIBILITIES (NPR 1800.1, NPR 8715.3, ANSI Z136.1) ........................................................................ 6

5.1 Laser Safety Officer (LSO) ...................................................................................................................... 7 5.2 Laser Safety Committee Chairperson (LSCC) ......................................................................................... 7 5.3 Laser Safety Committee (LSC) Members ................................................................................................ 7 5.4 Authority Having Jurisdiction (AHJ) ....................................................................................................... 7 5.5 Office of the Chief Health and Medical Officer (OCHMO) – NASA Headquarters ............................... 7 5.6 Laser Safety Review Board (LSRB) – NASA Headquarters ................................................................... 7 5.7 GRC LSRB Point of Contact ................................................................................................................... 7 5.8 Laser Safety Permit Requester ................................................................................................................. 7 5.9 Laser User (Operator) .............................................................................................................................. 8 5.10 Laser User’s (Operator’s) Supervisor ....................................................................................................... 8 5.11 Laser Facility Manager ............................................................................................................................ 8 5.12 Construction Laser Operator .................................................................................................................... 8 5.13 Medical Physician, Occupational Medicine Services............................................................................... 8 5.14 Human Capital Development Division Chief........................................................................................... 8 5.15 Occupational Health Branch Chief........................................................................................................... 8 5.16 Support Service Contractor Supervision .................................................................................................. 8 5.17 Project Manager-Airborne Class 3B/4 Laser Project ............................................................................... 8

6.0 REQUIREMENTS ............................................................................................................................................... 8 6.1 Training (ANSI Z136.1). ........................................................................................................................... 9

6.1.1 Laser Safety Instruction ............................................................................................................. 9 6.1.2 Laser Facility Instruction and Training ...................................................................................... 9 6.1.3 Other Training............................................................................................................................ 9

6.2 Medical Surveillance (ANSI Z136.1, NPR 1800.1) .................................................................................. 9 6.2.1 Eye Examination: Pre-Use ......................................................................................................... 9 6.2.2 Skin Examination: Pre-Use ........................................................................................................ 9 6.2.3 Eye and/or Skin Examination: Post-incident ........................................................................... 10

6.3 Hazard Classification of Lasers (ANSI Z136.1; (FDA) 21 CFR 1040.10) ............................................. 10 6.4 Laser Signage (ANSI Z136.1, NPR 8715.3) ........................................................................................... 10

6.4.1 Class Warning Signs. —Required for All Areas Where Class 2M, Class 3B and Class 4 Lasers Are In Use ........................................................................................................ 10

6.4.2 Class Warning Signs.—May be required for Areas Where Class 2 and Class 3R Lasers Are In Use .................................................................................................................... 10

6.4.3 Other Signs .............................................................................................................................. 10 6.4.4 Obtaining Signs ........................................................................................................................ 11

6.5 Labels for Lasers and Laser Systems (ANSI Z136.1; FDA 21 CFR 1040.1) ......................................... 11 6.5.1 Specific Laser Labeling Requirements .................................................................................... 12

6.6 Laser Standard Operating and Alignment Procedures (ANSI Z136.1, NPR 8715.3) .............................. 12 6.7 Emergency Procedures and Laser Incident/Accident Response/Reporting (GLP-QS-

8715.1.21. NFPA 115) ................................................................................................................... 13 6.8 Control Measures for Laser Activities (ANSI Z136.1, 21 CFR 1040) .................................................... 13

6.8.1 General Discussion on Engineering and Administrative Controls ........................................... 13 6.8.2 Entryway Controls ................................................................................................................... 14 6.8.3 Class-Based Control Measures ................................................................................................ 15

6.9 Additional Requirements for Outdoor Laser Activities and Airborne Laser Operations ( NPR 1800.1, NPR 8715.3, AC 70-1) .............................................................................................................. 16 6.9.1 Hazard Analysis for Outdoor Class 3B and 4 Lasers ............................................................... 16 6.9.2 Modification to Commercially Off the Shelf Systems (COTS) ............................................... 16





6.9.3 Outdoor Laser Activities near Airports .................................................................................... 16 6.9.4 Coordination with FAA ........................................................................................................... 16 6.9.5 Department Of Defense (DOD) Sites and DOD-Laser Activities ........................................... 16 6.9.6 NASA Laser Safety Review Board (LSRB) ............................................................................ 16 6.9.7 Enclosures, Controls and Precautions for Airborne Lasers ...................................................... 17 6.9.8 Software for Airborne Lasers ................................................................................................... 17

6.10 Laser Safety Permit Process (GLP-QS-8715.1.1A, NPR 8715.3) .......................................................... 17 6.10.1 Overview .................................................................................................................................. 17 6.10.2 Details ...................................................................................................................................... 17

6.11 Requirements.—Construction Lasers ((OSHA) 29 CFR 1926.54; FAA Order 7400.2; GLP-QS-8715.1.1A) ....................................................................................................................................... 18 6.11.1 Construction Laser Operator Training ..................................................................................... 18 6.11.2 Controls for Using Construction Lasers ................................................................................... 18 6.11.3 Procedures for Construction Lasers ......................................................................................... 19

6.12 Inventory of High Power Laser Devices (NPR 1800.1) ......................................................................... 19 6.13 FDA Laser Product Requirements (NPR 1800.1, NPR 8715.3) ............................................................. 19 6.14 Procurements And Transfers (NPR 1800.1) ........................................................................................... 19

7.0 RECORDS ......................................................................................................................................................... 19 8.0 REFERENCES ................................................................................................................................................... 20 APPENDIX A. —DEFINITIONS AND ACRONYMS .............................................................................................. 21 APPENDIX B. —CURRENT AND LEGACY SIGNAGE ........................................................................................ 23 APPENDIX C. —INTERLOCK SYSTEMS .............................................................................................................. 27

List of Figures Figure 6.1.—Temporary Controlled Area Notice Sign................................................................................................ 11 Figure 6.2.—Example Illuminated Warning Sign. ...................................................................................................... 11 Figure 6.3.—Aperture Label. ....................................................................................................................................... 12 Figure B.1.1.—ANSI Z136.1-2014 Class 2 CAUTION Sign ..................................................................................... 23 Figure B.1.2.—ANSI Z136.1-2014 Class 3R CAUTION Sign ................................................................................... 23 Figure B.1.3.—ANSI Z136.1-2014 Class 3B WARNING Sign.................................................................................. 24 Figure B.1.4.—ANSI Z136.1-2014 Class 4 WARNING Sign .................................................................................... 24 Figure B.1.5.—ANSI Z136.1-2014 Class 4 DANGER Sign ....................................................................................... 25 Figure B.2.1.—ANSI Z136.1-2000/2007 CAUTION Sign ........................................................................................ 26 Figure B.2.2.—OSHA Caution Sign ........................................................................................................................... 26 Figure B.2.3.—ANSI Z136.1-2000/2007 DANGER sign ........................................................................................... 26 Figure B.2.4.—OSHA Danger Sign ............................................................................................................................ 26 Figure C.3.1.—Example Of Laser Facility Layout ...................................................................................................... 29 Figure C.3.2.—Non-Isolated Bypass Feature Example ............................................................................................... 29 Figure C.3.4.—Simplified Interlock Circuit Diagram ................................................................................................. 30 Figure C.3.5.—Simplified block diagram of bypass isolation module ........................................................................ 30





Chapter 13—Laser Safety

Note: The current version of this chapter is maintained and approved by the Safety and Health Division (SHeD). The last revision date of this chapter was June 2017. The current version is located on the Glenn Research Center (GRC) intranet within the BMS Library. Approved by Chief of Safety and Health Division.

1.0 PURPOSE

This chapter provides requirements for the safe use of lasers and laser products at the GRC’s Lewis Field and Plum Brook Station.

2.0 APPLICABILITY

This chapter is applicable to all civil servant and contractor employees assigned to GRC sites and to any NASA-controlled, Government-owned facilities associated with GRC. This document applies to the operation of lasers at wavelengths between 180 nanometer and 1 millimeter. Examples of lasers and laser systems that this document applies to may include

• commercially available lasers that are used as a part of an experiment or laser development • commercially available lasers that have been modified, assembled, or incorporated into a device built by

GRC personnel • GRC designed or built lasers or laser systems • commercially available devices utilizing high-power lasers for heat-dependent activities such as welding,

parts prototyping, or laser cutting • commercially available devices utilizing lower power lasers for analytical or construction-related activities

The evaluation of potential hazards associated with such lasers or laser systems is typically accomplished via the Center’s safety permit process and construction health and safety plan (HaSP) review process, although other mechanisms may be employed in atypical situations.

In this chapter, all mandatory actions (i.e., requirements) are denoted by statements containing the term “shall.” The terms “may” or “can” denote discretionary privilege or permission, “should” denotes a good practice and is recommended, but not required, “will” denotes expected outcome, and “are” or “is” denotes descriptive material

This document does not apply to lasers incorporated into certain commercially available devices used by the general public, unless opened, serviced, modified, or incorporated into a device built by or for GRC, or as specifically addressed in this document. The laser safety officer (LSO) will determine which devices are to be covered by the Center’s laser safety program. Although misuse of these lasers may pose a hazard, it is generally accepted that the risk of injury from these devices is minimal if used as intended by the manufacturer. Examples of these lasers and laser systems not covered by this document include compact disc players and laser printers.

Laser pointers, as defined by the Food and Drug Administration (FDA), are currently not subject to conditions within this chapter. Such FDA-compliant devices have very limited power output. The reader should be advised that many higher output “handheld” lasers are currently available in the market place, some at very low cost. These devices can pose a significant eye hazard and shall not be used as laser pointers. Those desiring to procure such devices for use in research activities should be aware that evaluations of such devices have shown that their actual output parameters may not match the specifications claimed by the manufacturer or distributor. Output power levels can vary (high or low) from those stated and the emission may include other wavelengths of laser energy, which can present an additional hazard. Questions about these high power handheld lasers should be addressed to the LSO.

3.0 BACKGROUND

A laser is a device that produces an intense, coherent directional beam of light energy. The light characteristics of these lasers vary greatly. Laser wavelengths can range from the low ultraviolet (UV) to the far infrared. Emissions can be continuous wave or pulsed. Power and average power output can range from nanowatts to kilowatts.





GRC personnel employ a wide range of lasers. Some of which pose little hazard to users while others can cause severe injury or death. Most lasers at GRC can damage the eyes of anyone who looks directly into the beam or its specular (i.e., mirror-like) reflection. In addition, diffuse reflections created by some high-power laser beams can cause severe and permanent eye damage. High-power laser beams can also burn exposed skin, ignite combustible materials, and heat materials resulting in generation of hazardous fumes, gases, debris plasmas, and/or nonionizing radiation.

Note: The most common hazard when working with lasers is eye injury. To prevent such an injury, workers shall avoid looking directly into the laser beam or its specular reflections. This rule shall be followed regardless of the protective eyewear worn or the type of hazard classification of laser unless specifically authorized in support of research being conducted.

The classification of lasers and laser systems is based on their emission parameters and ability to cause injury.

• Class 1 lasers (or laser systems) pose no hazard if used in their designed state. • Class 1M lasers are considered not to pose a hazard to the eye during unaided viewing conditions but may

pose an eye hazard over an extended period when collecting optics (e.g., eye loupes, binoculars, or telescopes) are in use.

• Class 2 and 3R (formerly 3a) lasers are considered low- to medium-hazard lasers and could cause eye damage if viewed directly and intentionally.

• Class 2M lasers are considered to pose low degree of hazard to the eye during unaided viewing conditions but may pose an eye hazard over a relatively short period when collecting optics (e.g., eye loupes, binoculars, or telescopes) are in use.

• Class 3B lasers present a high-hazard for potential eye injury from an inadvertently-viewed direct beam and require more stringent controls.

• Class 4 lasers create additional hazards related to their potential for serving as an ignition source as well as causing skin injuries. Consequently, these lasers may require other engineering controls to mitigate such hazards.

Equipment and optical apparatus required for producing and controlling laser energy also introduces other potential hazards, including high voltage, high pressure, cryogenics, noise, target induced radiation, flammable materials, laser dyes and solvents, and toxic fluids and gases. These hazards are known as ‘non-beam hazards’, and are responsible for a high portion of all serious injuries and deaths related to laser use.

4.0 POLICY

This document describes the different types of lasers used at GRC, their classifications, and the required controls for each classification. It describes the responsibilities of personnel who work with lasers or supervise laser operations and identifies the training required for all GRC operations involving laser use. Unless specifically stated otherwise in this document, work standards for the safe operation of lasers and laser systems at GRC shall follow requirements of NPR 1800.1, “NASA Occupational Health Program Procedures”, including adherence to requirements set forward by the Laser Safety Review Board (LSRB) for outdoor laser activities, and 21 Code of Federal Regulations (CFR) 1040, U.S. FDA, “Performance Standards for Light-Emitting Products,” Sections 1040.10—Laser products 1040.11—Specific laser products, as well as recommendations of the American National Standards Institute (ANSI) Z136.1–2014 - Safe Use of Lasers, ANSI Z136.8-2012 - Safe Use of Lasers in Research, Development or Testing, and ANSI Z136.6–2005 - Safe Use of Lasers Outdoors, or their subsequent revisions. The Center’s LSO is charged with establishing and maintaining adequate policies and procedures for the control of laser radiation hazards. Compliance with the responsibilities and requirements of this chapter are measured and verified through the use of programmatic self-assessments, regulatory, and Agency audits and internal field inspections.

5.0 RESPONSIBILITIES (NPR 1800.1, NPR 8715.3, ANSI Z136.1)

Note: The LSO “duties and responsibilities” identified in Appendix A of the ANSI Z136.1 standard are performed by either the GRC LSO or the Laser Safety Committee Chairperson (LSCC), as appropriate.





5.1 Laser Safety Officer (LSO)

Shall ensure laser activities are conducted in accordance with NASA guidelines and recommendations made in the ANSI Z136.1, Z136.6 and Z136.8 standards for the safe use of lasers. The LSO is not necessarily the LSCC. If the LSO is not also the LSCC, then the LSO will serve as a member of the laser safety committee (LSC).

5.2 Laser Safety Committee Chairperson (LSCC)

Shall lead laser safety permit evaluations in accordance with the Center’s safety permit process and provide guidance to the safety permit requester on how to satisfy permit conditions. The LSCC shall approve laser safety permits and has discretionary authority to waive typical permit requirements when alternate means/methods provide adequate protection. In addition the LSCC shall, in accordance with the Center’s current electronic safety permit process, maintain any documentation package (paperwork, procedures, drawings, etc.) used in evaluation if the documentation was not uploaded into the electronic safety permit system.

5.3 Laser Safety Committee (LSC) Members

Shall participate in or, if designated by the LSCC, lead laser safety permit evaluations and, as needed, provide guidance to the safety permit requester on conditions of safe laser use. LSC members will provide input to the committee chairperson regarding the acceptability of the proposed laser activity being evaluated. As needed, ad-hoc reviewers may by designated as LSC Members by the LSCC for certain evaluations requiring an expanded level of subject matter expertise.

5.4 Authority Having Jurisdiction (AHJ)

Shall provide criteria on facility requirements related to fire and life safety for areas where laser use presents a fire hazard. The evaluation of the subject laser facilities against these requirements could be performed by the AHJ, their designee, or by a designated representative of the SHeD.

5.5 Office of the Chief Health and Medical Officer (OCHMO) – NASA Headquarters

Shall resolve conflicts between the Center and States, the U.S. Military, and other federal agencies. Shall provide guidance and advice to GRC on laser and non-laser optical radiation. Shall ensure Center laser and non-laser optical radiation programs are assessed for efficacy through regular periodic reviews.

5.6 Laser Safety Review Board (LSRB) – NASA Headquarters

Shall review proposed use of all outdoor lasers under NASA purview to ensure compliance with applicable regulatory requirements and adherence to exposure limits. Shall make recommendation to the Agency on matters related to outdoor laser use and the review of use of all outdoor lasers under NASA’s purview. Shall review complaints from Federal Aviation Administration (FAA) or the US. Military, and provide guidance on continuation of operations.

5.7 GRC LSRB Point of Contact

The GRC LSRB Point of Contact will submit to the LSRB all laser safety packages in accordance with the LSRB Charter and associated policies and procedures.

5.8 Laser Safety Permit Requester

Shall follow the Center’s process for obtaining a safety permit and work with the LSC in satisfying conditions for the permit. The permit requester shall comply with any compliance requests from the LSO/LSCC.





5.9 Laser User (Operator)

Shall satisfy training and any medical surveillance requirements of this chapter in addition to working in a safe manner in accordance with established procedures for his/her lab, area, room, or cell. The laser user should express his/her concerns or questions regarding potential safety issues to his/her management or to the LSO.

5.10 Laser User’s (Operator’s) Supervisor

Shall ensure laser users meet requirements specified in applicable laser safety permits or those for/by any laser facilities. Also, for Support Service Contractors (SSC), supervisors may be required to maintain medical surveillance and training records.

5.11 Laser Facility Manager

Shall ensure his/her facility satisfies conditions for safe laser use designated by the LSC, any local procedures, and if necessary, the AHJ.

5.12 Construction Laser Operator

Shall obtain training to become qualified for construction laser use and shall operate such laser products in accordance with the manufacturers’ specifications and following general safe use practices. The construction laser operator shall maintain proof of his/her qualification in his/her possession at all times during laser use per 29 CFR 1926.549(b).

5.13 Medical Physician, Occupational Medicine Services

Shall maintain complete, accurate records of any laser medical examinations for personnel in the medical surveillance program. Records shall be retained for at least 30 years. Results of examinations shall be discussed with employees as needed. For SSC, such records may alternately be maintained by the employer. The Medical Director shall also be responsible for identifying examination elements following a laser exposure incident.

5.14 Human Capital Development Division Chief

Shall maintain records for employee completion of laser safety courses and any associated examinations.

5.15 Occupational Health Branch Chief

Shall provide support to the LSO in the performance of their duties.

5.16 Support Service Contractor Supervision

If applicable, shall maintain records for employee completion of laser safety courses and any associated examinations as well as records of any medical evaluations or examinations triggered by a potential above maximum permissible exposure (MPE) exposure.

5.17 Project Manager-Airborne Class 3B/4 Laser Project

Shall verify project’s compliance with this document and NPR 8715.3. Shall identify the airborne use of Class 3B and Class 4 lasers early in the system acquisition process and track their use throughout the program life cycle. Shall work with the LSO and LSC to assess the safety aspects, compliance with safety requirements, and resolution of laser safety-related problems.

6.0 REQUIREMENTS

Note: The use of construction lasers for sighting and surveying activities is addressed in Section 6.11.





6.1 Training (ANSI Z136.1).

6.1.1 Laser Safety Instruction

Laser safety training at GRC is split into two training curriculums, one for those using high power (class 3B or 4) lasers and one for those using lower power (Class 2 or 3R/3a) lasers. As needed, the LSO can clarify questions regarding the need for laser safety training. Records of training completions shall be maintained by the Human Capital Development Division, or, in certain instances, by the SSC employer of a laser operator.

6.1.1.1 Laser Safety Training for High Power Lasers

Laser safety training shall be required for individuals who use Class 3B or 4 lasers or operate certain Class 1 laser systems that contain embedded Class 3B or 4 lasers. The source, content, and refresher periodicity of this training are specified by the GRC LSO. While this training is typically delivered via SATERN (System for Administration, Training and Educational Resources for NASA), it could alternatively consist of viewing training videos (from the Learning Center), classroom instruction, or other online or computer-based training specified by the LSO. Periodic refresher training is required every 2 years (biennial).

6.1.1.2 Laser Awareness Training for Low Power Lasers

The awareness level laser safety instruction was developed for those only working with lower power, Class 2 or 3R (formerly 3a), lasers. This laser awareness training shall be required for individuals who use or operate Class 2 or 3R/3a lasers that are covered by this document. The source, content, and refresher periodicity of this training are specified by the GRC LSO. The laser awareness training is typically provided via SATERN, although, an instructor-led course can be arranged with the LSO. Also, completion of the laser safety training for higher power lasers would satisfy this requirement. Periodic refresher training is required every 4 years (quadrennial).

6.1.2 Laser Facility Instruction and Training

Laser users/operators shall also satisfy training and/or work experience requirements specified for the area, room, cell, or lab where the lasers are present. These requirements may be specified on the NASA GRC-580, “Qualified Operators List,” or equivalent form associated with a laser safety permit, or in the local procedures for the area. Typically, users/operators will receive instruction on the specific hazards of the laser(s) used in the area, along with protection measures to ensure risks are minimized.

6.1.3 Other Training

The LSO may periodically coordinate more advanced laser safety training for GRC personnel.

6.2 Medical Surveillance (ANSI Z136.1, NPR 1800.1)

6.2.1 Eye Examination: Pre-Use

Agency policy as described in NPR 1800.1D no longer requires pre-use, or, “baseline,” laser eye examinations for those individuals operating Class 3B and 4 lasers. Additionally, the ANSI Z136.1 eliminated this requirement in the 2007 revision.

6.2.2 Skin Examination: Pre-Use

Examination of the skin is not required for pre-placement examinations of most laser workers; however, it is suggested for employees with history of photosensitivity who are working with UV lasers where exposure to diffuse reflections are anticipated. Any previous dermatological abnormalities and family history are reviewed. Any current complaints concerned with the skin are noted as well as the history of medication usage, particularly concentrating on those drugs that are potentially photosensitizing. In most cases of UV laser use, operators will be advised to limit skin exposure.





6.2.3 Eye and/or Skin Examination: Post-incident

Any employee with a known or suspected laser eye and/or skin injury shall contact GRC’s Occupational Medicine Services to arrange for a post-exposure exam. This exam shall include those items listed above as deemed necessary by the facility occupational health physician.

6.3 Hazard Classification of Lasers (ANSI Z136.1; (FDA) 21 CFR 1040.10)

Classification of laser products is based upon the maximum output power or radiant energy available for the intended use. The LSO would normally rely on the manufacturer’s information for most commercial laser products and not need to perform measurements of laser output. The LSO shall review the manufacturer’s stated classification or that indicated on product labels to verify accuracy. There are instances where manufacturers will apply a conservative hazard label to a family of lasers which could potentially overstate power output or even classification of certain lower-power variants within the family of lasers. Alternatively, many lower quality/cost laser devices, including laser pointers, may have emissions that exceed the label specifications.

6.4 Laser Signage (ANSI Z136.1, NPR 8715.3)

6.4.1 Class Warning Signs. —Required for All Areas Where Class 2M, Class 3B and Class 4 Lasers Are In Use

Signs shall be posted in visible locations at/near access points to facilities where Class 2M, Class 3B and/or Class 4 lasers are used. Laser signage shall follow the ANSI Z136.1 standard. ANSI Z136.1-2014 modified its signage format to match the general requirements for signage in the ANSI Z535 series. This is a three pane structure using both pictograms and wording to communicate hazard. “CAUTION” signs shall have black letters in the header on a yellow background, the sunburst on the left pane and appropriate verbiage in the right pane. “WARNING” signs shall have black lettering in the header with an orange background, the sunburst on the left pane and appropriate verbiage in the right hand pane. “DANGER” signs shall have white lettering in the header on a red background, the sunburst in the left pane and appropriate verbiage in the right pane. See APPENDIX B for additional information and examples. The LSO will review the wording on signs/labels in use or proposed for use. A degree of freedom exists for verbiage to allow signs to convey specific information that is pertinent to the laser in use. The LSO should be consulted when questions about postings, signs, or labeling exist; he/she will provide direction to the laser facility supervisor or laser safety permit requestor.

Note: Legacy signs and labels based upon obsoleted versions of the ANSI Z136.1 standard, including those posted and those in stock, are allowed to be used for laser hazard communication; however, conflicting signage should be avoided.

Note: Typical verbiage is specified in APPENDIX B for each sign. Alternate site or application-specific statements may also be used.

6.4.2 Class Warning Signs.—May be required for Areas Where Class 2 and Class 3R Lasers Are In Use

Controlled area signs may be posted in areas where Class 2 or Class 3R laser beams propagate through free space. The LSO/LSCC will make this determination during the evaluation process.

6.4.3 Other Signs

6.4.3.1 Specific Message Signs

Specific messages may be written on laser controlled area signs. Examples of such pertinent precautionary instructions could include “Laser Alignment in Progress, Appropriate Eye Protection Required for Entry,” “Restricted Area,” “Do Not Enter When Light is ON,” or “When These Enclosure Panels are Removed, This Area is Within a Laser Hazard Zone.”

6.4.3.2 Temporary Controlled Area Signs

A white/blue and black Notice sign (Figure 6.1) with a sunburst may be used to denote temporary controlled laser areas during periods of servicing or maintenance. Verbiage on such a sign will typically include:





- Warning of laser hazard (Ex. “Laser Service in Process”)

- Specific policies in effect (Ex. “Do Not Enter”)

- Severity of hazard (Ex. “Class 4 Laser, λ = 532nm, 50 kHz, 150 mJ/pulse”)

- Applicable instructions (Ex. “Laser Protective Eyewear required. OD 7.0”

The Notice sign is placed outside the controlled area while the appropriate laser controlled area sign (i.e. signal word) is required within the controlled area.

6.4.3.3 Visible Warning Devices.

Visible warning devices (Figure 6.2) that are active during laser activities provide an added safety measure since they reduce any potential complacency, which can develop when signs are continually posted. Their purpose is to ensure that persons who are about to enter a laser-controlled area are aware that a laser is emitting or is about to begin emitting laser radiation within the area. A visible warning device is recommended for Class 3B lasers, and required for Class 4. These warning devices are in addition to controlled area postings.

Visible warning devices that are illuminated are preferred at the GRC. Such signs are highly recommended for existing Class 4 laser operations, especially those involving nonvisible wavelengths, and shall be required for any new Class 4 laser facilities. These lighted signs shall be posted near the entrance to a laser controlled area to serve as a warning to individuals not to enter. Example verbiage for the illuminated sign might read: “Laser On, Do Not Enter” or “DANGER, Laser On”. The light shall be visible through the operator’s laser protective eyewear.

An alternative to an illuminated sign would be a mechanically operated warning that is immediately adjacent to a sign specifying the desired message or warning. Because these signs inherently rely upon a manual action (administrative control) they are not preferred at the GRC.

Figure 6.1.—Temporary Controlled Area Notice Sign. Figure 6.2.—Example Illuminated Warning Sign.

6.4.4 Obtaining Signs

Many standard laser signs can be obtained from the LSO. Those signs not available from the LSO shall be procured by the organization sponsoring the subject laser facility. When signs are no longer needed for an area, they should be returned to the LSO who can facilitate their re-use. The LSO also has “Laser On, Do Not Enter” warnings that are used to create illuminated signs; the lighted box itself is not provided by the LSO. Wording on signs can be varied somewhat using label-making machines or by other methods, but, the wording on signs/labels in use or proposed for use shall be reviewed by the LSO.

6.5 Labels for Lasers and Laser Systems (ANSI Z136.1; FDA 21 CFR 1040.1)

Note: Legacy signs and labels based upon previous versions of the ANSI Z136.1 standard, including those posted and those in stock, are allowed to be used for laser hazard communication; however, conflicting labeling should be avoided.

The FDA requires that laser products be labeled by the laser or laser product manufacturer. One exception to this requirement would be lasers provided to original equipment manufacturers (OEMs) as components for manufacturing a product/system containing the laser. If such a laser was purchased, it may not have been appropriately labeled and the individual purchasing this device shall contact the LSO to ensure the laser is





appropriately labeled and classified. In addition, the LSO shall be contacted when alterations or modifications are planned for a laser device as these might affect the laser classification.

Also, it is worth noting that manufacturers may “over label” their laser devices. That is, provide a more hazardous label warning than is required. Manufacturers typically do this in an effort to simplify their labeling process by creating a generic label that works for a group of lasers. Manufacturers may also erroneously place a label on a laser with an erroneously lower class rating. Laser documentation should be consulted to confirm the exact class of the laser, or, such an inquiry can be addressed to the LSO. Again, the LSO should be consulted when questions about postings, signs, or labeling exist; they will provide direction to the laser facility supervisor.

6.5.1 Specific Laser Labeling Requirements

6.5.1.1 Class Label – Class 2 and Above Lasers

Lasers shall be labeled with the appropriate CAUTION, WARNING, or DANGER label, based on the laser’s classification and power output. The label specifications are identical to the class posting requirements specified above and within Appendix B. If the laser is embedded within a device or housed in an enclosure, an appropriate label shall be placed on this outer surface to provide the needed warning.

6.5.1.2 Aperture Label

An aperture label (Figure 6.3) shall be required on a laser or laser device to identify the laser emission point. Typically, this is a small label and may include an arrow pointing to the location of the beam output. This label shall be clearly visible. Additional labels may be applied if positioning of the laser inhibits or blocks view of the aperture label. Similarly, if the laser is mounted within an enclosure from where the laser beam is emitted, that point of emission shall be identified with an aperture label.

Note: Exact wording on the aperture label may vary.

Figure 6.3.—Aperture Label.

6.5.1.3 Non-Standard Configurations and Labels

Certain laser configurations do not lend themselves to the standard application of labels. Examples include small diode laser devices, inadvertent obscuring by a jig, or connections of optical fibers carrying laser energy. Recognizing the intent of this requirement, which is hazard communication, other labeling accommodations may be utilized such as tethering labels on fibers near connections, or, relocating a label to a more conspicuous location.

6.5.1.4 Other Labels

As with signs, labels can also be used to communicate specific messages about a laser product. For example, a danger label reading “Removal of this Panel Makes This System a Class 4 Laser Device” could be applied to a removable panel on a Class 1 system containing an embedded Class 4 laser.

6.6 Laser Standard Operating and Alignment Procedures (ANSI Z136.1, NPR 8715.3)

Class 3B and 4 lasers shall have written standard operating procedures (SOP) and alignment procedures that are approved by the LSO. These procedures are typically provided by the permit requester during the safety permit request process. The LSO’s approval of these procedures shall, somehow, be documented during the safety permit process. If one person acts as both the LSO and LSCC, the LSCC’s signature on the laser safety permit (NASA GRC-919) shall denote his/her approval of the attached procedures.

The written procedures shall be based on Accessible Emission Levels and shall include a description of the laser(s) being used as well as the specific steps followed to ensure the device is being used safely (i.e. safety precautions).





These steps may include a checklist of precautions to be observed or followed prior to the laser activity. Specifications for laser protective eyewear shall also be included in the procedures by indicating the required optical density (O.D.) for each wavelength of interest. Requesters can get this information from the LSO.

Laser alignment activities, in particular, can pose a significant ocular hazard to users and the procedures outlining the methodology of the task are critical to minimizing this hazard. Again, if there is potential exposure to laser radiation above the applicable MPE level, then controls shall be followed. Approaches to performing alignments include:

• Operating laser at lowest power setting that permits alignment • Reducing laser power via other means (neutral density filter, and optical attenuator) during alignment • Use of a coaxially oriented low-power alignment laser • Use of burn paper, fluorescing paper/material, or other indicating medium to identify beam location • Wearing protective eyewear while laser emission (irradiance or radiant exposure) exceeds the applicable

MPE • Breaking down alignment activity into stages, the first being a “rough” alignment requiring various

protective measures and the second being a “fine-tuning” alignment involving more procedural and work practice control measures

• Wearing skin protection (gloves and long sleeves) if aligning Class 4 lasers above the skin MPE • Clearing area, room, lab, or cell of unnecessary personnel during alignment

Standard operating and alignment procedures do not need to reproduce detailed and complex laser operating procedures found in the manufacturer’s instruction manuals. Rather, the requester can provide specific references to the procedures within such documents. As needed, the LSO or LSCC can provide some assistance and feedback in preparing the procedures.

6.7 Emergency Procedures and Laser Incident/Accident Response/Reporting (GLP-QS-8715.1.21. NFPA 115)

SOP for high power lasers (Classes 3B and 4) shall include emergency procedures which address operator actions in response to possible laser-related injuries and, or certain lasers, laser-induced fires.

Notification, investigation, and documentation of incidents of actual or suspected exposure to potentially harmful laser radiation shall follow the process identified in Chapter 21 “Mishap and Close Call Reporting, Investigating, and Recordkeeping” of the Glenn Safety Manual.

6.8 Control Measures for Laser Activities (ANSI Z136.1, 21 CFR 1040)

6.8.1 General Discussion on Engineering and Administrative Controls

Aspects of the laser activity that influence the hazard evaluation and thereby, influence the application of control measures, include (1) the laser or laser system’s capability of injuring personnel or interfering with task performance, (2) the environment in which the laser is used, including access to the beam path (considering enclosures, baffle, beam, etc.), and (3) the personnel who may use or be exposed to laser radiation. Aspect (1) is fairly straightforward and is addressed by the ANSI laser safety standard. Aspects (2) and (3) can vary with each laser application and cannot be readily standardized. While the total hazard evaluation shall consider all aspects, typically aspect (1) has the greatest influence upon which control measures are applicable.

So, when the intensity of an accessible laser beam exceeds the applicable MPE level, appropriate controls shall be implemented to minimize the potential hazards to laser operators and bystanders. These measures include both engineering and administrative controls, with the former being the preferred course of action. “Accessible” laser beams are those that are not enclosed or contained, and are oriented such that the direct beam or inadvertently-reflected beam could pose a potential eye or skin hazard. Beam accessibility is typically greater during laser alignment activities, necessitating greater controls.





Typical engineering controls include, but are not limited to, protective housings/enclosures, interlocked entryways or beam enclosures, key control, beam path enclosures, beam stops/dumps, beam attenuators to limit output level, and shades/curtains over windows. Other engineering controls may be required to maintain normal operating conditions or to monitor for failure conditions. Common administrative controls include alignment and operating procedures, limiting or restricting access, emission output limitations, the use of protective eyewear, the use of skin protection, education and training, and the use of temporary barriers and curtains. As mentioned, the use of engineering controls is typically favored over administrative controls since the latter relies on a human-dependent action.

6.8.2 Entryway Controls

Note: Appendix C is a non-normative appendix aimed to provide background information, design and development ideas, and system requirements related to Facility Interlock Systems.

Because open-beam configurations are commonly found in research environments such as the GRC, entryway controls allowing for ingress/egress to/from a laser-controlled area are an important part of safe-use practices. Entryway controls shall be required for most Class 3B and all Class 4 laser activities and the LSO shall be responsible for specifying the type of control required for a laser facility. Individuals with questions about what entryway controls are required for a new facility can contact the LSO. There are three basic options for controlling entry to a laser controlled area. The basic types are as follows:

6.8.2.1 Non-defeatable Entryway Controls

These utilize a built-in interlock switch that will secure the laser beam (either secure power or close a shutter) when an entry door is opened. Non-defeatable entryway controls are engineering controls; they are to be used for long-term laser operation.

Note: Interlock features on enclosure access panels or facility/laboratory doors are to be “Fail Safe,” which means that the system goes into, and, remains in a safe mode until a manual action is performed to reset the system. For example, an interlock system which has reacted to a door opening by securing the laser should not automatically re-enable the laser once the door has closed. Rather the laser operator must perform a manual action prior to re-enabling laser beam emission. In most scenarios, manual resets of both the room interlock system and laser controller are required before accessible laser emissions are observed. This is the preferred operational setup. A less-desirable, yet compliant, scenario would involve a setup were only the room interlock system OR the laser controller required a manual reset after being tripped.

6.8.2.2 Defeatable Entryway Control

Similar to the “Non-defeatable Control” described above with the addition of a temporary (typically, 20- to 30-second) bypass or ingress/egress feature, which will allows entry into/out of an area without securing the beam. Utilizing this type of control requires that no laser beam hazard exists at the point of entry. Ideally, the configuration of the laser facility affords this level of safety at the entryway. However, when this is not the case, administrative controls may be necessary. Typically, there would also be a procedural aspect to this type of control whereby the person entering or exiting the laser controlled area verifies that an individual who might be standing outside the access point to the area will not be exposed to an emission hazard while the door is open. Only Qualified Operators or personnel directly supervised by a Qualified Operator are permitted to utilize a Defeatable Entryway. An ingress/egress bypass feature must be isolated to the designated ingress/egress point; meaning that the interlock system is only bypassed for that specific access point. All other ingress/egress points must remain actively interlocked to prevent the potential for inadvertent exposure to laser hazards. Defeatable entryway controls are engineering control; they are to be used for long-term laser operation.

6.8.2.3 Procedural Entryway Controls

Procedural entryway controls are only to be used for temporary laser activities, or, when facility interlocks are not feasible or are inappropriate. Occasionally situations at GRC require the use of procedural entryway controls where Class 4 laser systems are in use, which requires direct review by the LSC and written approval from the LSCC. Procedural requirements and operating conditions for such an arrangement must be built into the Laser Safety Permit. A door, blocking barrier, screens, curtains, etc., are used to block, screen, or attenuate the laser radiation at





the entryway in conjunction with a posted barricade. The laser radiation at the exterior of these devices shall not exceed the applicable MPE, nor shall any personnel experience any exposure above the MPE during the entry process. Sufficient warning signs and, possibly, an additional barricade(s) are important parts of implementing these measures.

6.8.3 Class-Based Control Measures

The control measures described below are general in nature for the specific class of laser being used. The LSO and or LSCC shall make a final determination of what control measures will be required for a facility and can modify these general requirements on a case-by-case basis. Note that laser classification during alignment activities may be higher than that during normal operation of some laser systems.

6.8.3.1 Class 2 and Class 2M Laser Control Measures

• Training, signs (required for Class 2M), and labels (see above) • Protective eyewear – may be required in conditions where intentional long-term (> 0.25 seconds) direct

viewing of visible lasers is required.

6.8.3.2 Class 3R (Formerly Class 3A) Laser Control Measures

• Class 2 laser control measures • Protective eyewear may be required in conditions where intentional long-term direct viewing of lasers is

required. “Long-term” is considered > 0.25 seconds for visible wavelengths and > 10 seconds for invisible wavelengths.

6.8.3.3 Class 3B Laser Control Measures

• Class 3R laser control measures • Controlled area posting • Alignment and operating procedures (see above) • Entryway controls (see above) • Beam enclosure – interlocked (fail safe not required) access points (e.g. panels) or tool use required for

access. • Operate only in controlled environments, or, designated areas that have no unintended reflective or

transmitting surfaces. • Keep flammable materials/vapors away from laser unless specifically authorized by the operation/test plan. • Key controls

Note: Key control features are provided on high power lasers for the intent of preventing the inadvertent startup of such lasers. This safety feature lends itself well to laser use in an industrial environment rather than such activities at a government research facility. Consequently, the discretionary authority of the LSO may allow for alternate means or measures to satisfy the spirit of this specified control.

6.8.3.4 Class 4 Laser Control Measures

• Class 3B laser control measures • Skin protection (if accessible beam intensity exceeds skin MPE) • For FDA-compliant lasers, Class 4 laser devices are to have a manual reset feature on the system itself

which must be actuated if the laser is automatically secured for safety purposes. This would be in addition to resetting the room interlock system.

• Additional requirements stemming from the fire hazard analysis as described in 6.10.2.3. These can include conditions related to the laser system and beam line or requirements for the laser facility.





6.9 Additional Requirements for Outdoor Laser Activities and Airborne Laser Operations ( NPR 1800.1, NPR 8715.3, AC 70-1)

6.9.1 Hazard Analysis for Outdoor Class 3B and 4 Lasers

A member of the laser project team shall perform and document a comprehensive outdoor laser use assessment for the proposed activities involving Class 3B and Class 4 lasers.

For airborne activities, this hazard analysis shall assess catastrophic events and the need for very reliable, high-speed laser shutdown should such events occur and shall take into consideration the atmospheric effects on laser beam propagation, the transmission of laser radiation through intervening materials, the use of optical viewing aids, and resultant hazards (e.g. electrical, cryogenic, toxic vapors).

6.9.2 Modification to Commercially Off the Shelf Systems (COTS)

Quality assurance verification of laser output shall be obtained for all commercially off the shelf lasers used outdoors following modifications with the potential to alter beam output. Quality assurance verification shall be adequate to validate said classification.

6.9.3 Outdoor Laser Activities near Airports

Caution shall be exercised to prevent visual interference in flight hazard zones established by the FAA around airports.

6.9.4 Coordination with FAA

The LSO shall provide the appropriate regional FAA contacts with the “Notice of Proposed Outdoor Laser Operation(s)” form (FAA Form 7141) and other supporting documentation in accordance with FAA Advisory Circular, AC 70-1 “Outdoor Laser Operations” to allow the FAA to perform its review and analysis of the proposed outdoor or flight laser activity. The LSO will also coordinate any additional requests for information. Once received, the LSO shall share the FAA Letter of No Objection or other ruling with research and flight staff. Representatives of NASA’s Office of the Chief Health and Medical Officer will be copied on all communications.

6.9.5 Department Of Defense (DOD) Sites and DOD-Laser Activities

The LSO shall ensure that laser operations during any open-air laser scenario conducted on DOD-controlled ranges or test facilities or by DOD personnel are conducted in accordance with the Range Commanders Council Document 316-91, Laser Range Safety.

The LSO shall coordinate with, and gain permission from U.S. Strategic Command prior to propagation of the related mission’s laser beam above the horizon in accordance with the 28 February 2012 AIR FORCE MEMORANDUM FOR JFCC Space/J9 entitled Satellite Protection Guidance for the Laser Clearinghouse.

Also, for DOD laser activities involving NASA, the LSO shall ensure that requirements identified in DOD Instruction 3100.11 “Illumination of Objects in Space by Lasers” and Chairman of the Joint Chiefs of Staff Instruction 3225.01 “Illumination of Objects in Space by Lasers” are satisfied, as needed. These include:

• The LSO shall Coordinate with the Laser Clearinghouse to obtain a Site Window clearance where a planned laser operation has the potential for the beam to strike an orbiting craft;

• The LSO shall be on-site to monitor all such tests.

6.9.6 NASA Laser Safety Review Board (LSRB)

The LSO will submit to the Agency LSRB all laser safety packages in accordance with the LSRB Charter and associated policies and procedures. The LSRB will review proposed use of all qualifying outdoor lasers under NASA purview to ensure compliance with applicable regulatory requirements and adherence to exposure limits. All outdoor laser activities under the purview of LSRB shall abide by the requirements of the LSRB. The LSRB shall be the final review body for all NASA-sponsored outdoor laser operations, including ground based, and airborne laser missions.





6.9.7 Enclosures, Controls and Precautions for Airborne Lasers

Laser systems to be operated aboard NASA aircraft and spacecraft shall include a system of interlocks to prevent inadvertent laser beam output.

When such laser systems include a test circuit switch to override the ground interlock thereby allowing system test operations, maintenance, or service when not airborne, said test circuit switch shall be designed to preclude inadvertent laser system operation

For long-range laser shots from airborne sources, designate as large an exclusion area as practical to minimize the risk to the people outside the area.

The Pilot-in-Command shall ensure that the laser system is used in accordance with the test plan. The airborne crew is not to operate the laser except in accordance with the mission profile.

6.9.8 Software for Airborne Lasers

Airborne laser project personnel shall review the software to ensure that safety precautions are provided. In addition they shall ensure that laser software provides safety precautions for fast-moving lasers and prevents misdirected laser operations. Laser software development is subjected to a software safety analysis in accordance with chapter 1 of NPR 8715.3.

6.10 Laser Safety Permit Process (GLP-QS-8715.1.1A, NPR 8715.3)

6.10.1 Overview

Most laser operations subject to this chapter (see “APPLICABILITY” section) require a laser safety permit. The safety permit program is described in Chapter 1A of the NASA Glenn Safety Manual GLP-QS 8715.1. This process formalizes the hazard evaluation of laser activities and the resulting prescription of applicable control measures. The LSCC may waive the need for a safety permit if the conditions of use for the laser satisfy Class 1 criteria or if, based on his/her judgment, the circumstances of use offer sufficient protection for a temporary activity. In either case, that decision is up to the LSCC who will rely on input and recommendations of the LSO. When a safety permit is issued, the proposed laser operation is approved within the constraints listed on the safety permit, the corresponding qualified operators list, and the procedures and other documentation of correspondence supporting the permit.

6.10.2 Details

6.10.2.1 Preparation and Request Submission

Requesters are encouraged to contact the LSO/LSCC directly early in the permit process if they have any questions regarding laser safety permits and the associated requirements/controls. As needed, LSO, LSC members, or the LSCC will assist the requester in identifying specific controls to be implemented or actions to be conducted to satisfy typical conditions of a laser safety permit. The official permit request is initiated via the Centers’ electronic safety permit systems. Permit requesters input the necessary information to describe the activity and worker qualifications as well as upload the hazard analysis, operating/alignments procedures, and any other supporting documentation.

6.10.2.2 Coordinating Reviews

Once the LSO/LSCC receives notification that the laser safety permit request has been submitted, he/she will work to schedule the on-site formal evaluation by the LSC. A requester may also contact the LSCC or LSO prior to or during his/her permit initiation activities to discuss the proposed activity and controls or to request an informal preliminary evaluation. Typically, laser safety permit evaluations are conducted by at least two members of the LSC.

Additional ad-hoc members can be added to the LSC as needed. For certain high power laser activities, the LSC may be augmented with an ad-hoc reviewer familiar with fire and life safety requirements who will assist in evaluating the facility and laser installation.

At his/her discretion, the LSCC can limit the evaluation of a permit request to one reviewer. A typical scenario for a single reviewer would involve a simple permit request involving a low-hazard laser.





6.10.2.3 Permit Evaluation

During the onsite evaluation of the proposed laser activity, the LSC representatives (see above) shall meet with the safety permit requester and other pertinent staff to review the anticipated task and the specific use of laser radiation. Written operating and alignment activities shall also be assessed to determine their adequacy and accuracy. Working at a center that conducts research activities, it is sometimes not possible to outline exactly how a laser will be used, so, in such cases the methodology and basic approaches to handling the laser radiation will be reviewed. During the laser permit review, the LSC shall also verify the presence, adequacy, and functionality of any required interlock or enclosure system(s), protective eyewear and other protective equipment, and the adequacy of any other safety features or control measures.

The high concentration of radiant power within the beam of a Class 4, or higher power Class 3B, laser can be sufficient to ignite combustible materials. This can include flammable liquids, plastics, wood, fabrics, and gases. In addition to beam-initiated fires, non-beam fire hazards can include sparks or hot particles from materials, hazardous atmosphere caused by the buildup of fumes or laser generated air contaminants, and electrical faults. Appropriate design of the experimental layout should be adopted to minimize fire risks, as well as attention to housekeeping (clutter, spilled oils, paper towels, etc.). The LSC shall pay special attention to potential fire hazard scenarios when reviewing laser safety permit requests with Class 4 laser systems. Based upon the fire-hazard potential of a laser facility, specific accommodations/conditions for the facility or laser installation itself may be necessary to satisfy fire and life safety requirements.

6.10.2.4 Scope of Laser Safety Permits

Like standard safety permits, laser safety permits are issued as a vehicle for assuring that proposed activities are conducted in a manner to minimize potential health and safety risks to employees. The scope of a laser safety permit is to address the eye and skin hazards associated directly with the laser emission; as well as to address the fire hazard associated with laser use. If the activity also involves non laser radiation hazards, then a second, “standard,” safety permit might also be necessary to address those hazards not directly associated with the laser beam emission. For example, excimer lasers consume toxic (health hazard) gas in generating their desired UV wavelength, materials testing may involve hydraulically-actuated (safety hazard) test fixtures, or a microgravity experiment involving a pressurized (safety hazard) fuel (safety hazard) cylinder may use a high-power laser to visualize a combustion parameter. For each of these activities, both a “standard” safety permit, issued by the appropriate “area” safety committee, and a laser safety permit, issued by the LSC, would be required.

6.10.2.5 Safety Permit Expiration

Safety permits can be issued to cover time periods ranging from a day to several years. The periodicity of the permit renewal is left to the discretion of the LSCC, who signs/approves the permit. Safety permits and the associated qualified operators’ list are to be posted outside the lab/room/cell where the activity is being conducted, or should be available in accordance with facility process procedures.

6.10.2.6 Laser Safety Permit Documentation

The chair of the LSC shall follow safety permit process for uploading/archiving all documentation that was used in evaluating the permitted activity that was not uploaded into the electronic safety permit system.

6.11 Requirements.—Construction Lasers ((OSHA) 29 CFR 1926.54; FAA Order 7400.2; GLP-QS-8715.1.1A)

6.11.1 Construction Laser Operator Training

Per the OSHA construction standard for “Nonionizing Radiation,” 29 CFR 1926.54, employers for construction laser operators shall ensure that only qualified and trained employees install, adjust and operator such laser equipment. Additionally, proof of qualification of the laser equipment operator, which is to be provided by their employer, shall be available and in possession of the operator at all times.

6.11.2 Controls for Using Construction Lasers

Construction laser use, as described in this document, include commercially available products designed and intended for leveling/measuring activities with power emissions satisfying Class 3R (formerly Class 3A) limits for





visible lasers and Class 1 for other wavelengths; as a result, physical control measures are not typically required [because of the lower powers involved]. Strict adherence to the Health and Safety Plan (see section 6.11.3.2) precautions and written procedures shall be maintained. Intentional misuse of low-powered visible lasers, including construction lasers, shall be prohibited. Visual interference with “critical tasks” (e.g. operating a vehicle or piloting an aircraft) by Class 2 or 3R (formerly Class 3a) lasers is possible if they are used at dusk or night near airports or roads. Consequently, the use of visible construction lasers shall not be permitted during such time periods. This should have little impact on construction activities as such construction lasers are typically not used at night and would not be expected to create a direct or indirect hazard when operated by a “qualified” operator and when used as intended.

6.11.3 Procedures for Construction Lasers

6.11.3.1 Written Procedures for Safe Use of Construction Lasers

Contractors using construction lasers shall have established written procedures, which address, at a minimum, the following issues:

• use restriction to qualified persons • methods undertaken to minimize direct eye exposure potential (verifying beam path prior to firing,

considering beam termination, not positioning at eye level, prohibiting intentional direct viewing, etc.) • prohibited times of use (i.e., dusk or night)

6.11.3.2 Health and Safety Plan (HaSP) for Construction Activity

The contractor’s laser-use procedure/conditions shall be included in the HaSP written for the involved construction task. The contractor should also provide the OSHA-required proof of qualification for its construction laser operator(s) with the proposed HaSP. The Operational Safety Branch staff member charged with reviewing and accepting HaSPs shall approve the laser use on behalf of the LSO. Any questions regarding this document review shall be addressed to the LSO.

6.12 Inventory of High Power Laser Devices (NPR 1800.1)

A comprehensive inventory of hazardous laser systems shall be maintained and annually verified by the LSO. This listing includes only Class 3B and 4 lasers or laser systems. The inventory will be verified and updated on an on-going basis by the LSO, OHB staff, and/or others.

6.13 FDA Laser Product Requirements (NPR 1800.1, NPR 8715.3)

As applicable, the rules for laser products identified in 10CFR1040.10 and 1040.11 shall be followed unless a specific exemption is obtained from the FDA.

6.14 Procurements And Transfers (NPR 1800.1)

All procurements, use, transfer, and disposal of hazard nonionizing radiation generating equipment shall be coordinated with the designated radiation protection competent approval authority. For lasers, laser systems, non-laser optical radiation-generating equipment (UV lights, IR lights, or high intensity lights) this shall be the LSO.

7.0 RECORDS

• Laser Safety Permit, NASA GRC-919, and supporting documentation—Maintained in the Electronic Safety Permit System Database, or, by the LSCC

• Training Records—Maintained by Human Capital Development Division. In the case of a Support Service Contractor, these records could be maintained by the employer.

• Medical Exam Records—Maintained by Occupational Medicine Services. In the case of a Support Service Contractor, these records could be maintained by the employer.

• High Power Laser Device Inventory—Maintained by the LSO.





8.0 REFERENCES

Document Number Document Name

21 CFR 1040 U.S. Food and Drug Administration, “Performance Standards for Light-Emitting Products,” Section 1040.10—Laser products

29 CFR 1926.54 Occupational Safety and Health Administration, “Construction Health and Safety Standards,” Section 1926.54—Nonionizing radiation

GLP-QS-8715.1.1A NASA Glenn Safety Manual, Chapter 1A—Safety Permit System

GLP-QS-8715.1.17 NASA Glenn Safety Manual, Chapter 17—Construction Safety

GLP-QS-8715.1.21 NASA Glenn Safety Manual, Chapter 21—Mishap and Close Call Reporting, Investigating and Record Keeping

NPR 1800.1 NASA Procedural Requirement, “NASA Occupational Health Program Procedures”

NPR 8715.3 NASA Procedural Requirement, “NASA General Safety Program Requirements, Chapter 3 Section 15 – Non-Ionizing Radiation”

Order JO 7400.2 U.S. Federal Aviation Administration, Part 6, Chapter 29—Procedures for Handling Airspace Matters, Outdoor Laser Operations

AC 70-1 U.S. Federal Aviation Administration, Advisory Circular 70-1, “Outdoor Laser Operations”

ANSI Z–136.1 American National Standards Institute, “American National Standards Institute for Safe Use of Lasers: Z–136.1,” Publisher: Laser Institute of America, Orlando, FL, 2014.

ANSI Z–136.6 American National Standards Institute, “American National Standards Institute for Safe Use of Lasers Outdoors,” Z–136.6, Publisher: Laser Institute of America, Orlando, FL, 2005.

ANSI Z–136.8 American National Standards Institute, “American National Standards Institute for Safe Use of Lasers in Research, Development, or Testing,” Z–136.8, Publisher: Laser Institute of America, Orlando, FL, 2012.

NFPA 115 National Fire Protection Association, “Standard for Laser Fire Protection” NFPA, National Fire Protection Association, Quincy, MA 02169, 2016.





APPENDIX A.—DEFINITIONS AND ACRONYMS

American National Standards Institute (ANSI)

Authority Having Jurisdiction (AHJ)

Code of Federal Regulations (CFR)

Construction Laser.—Commercially available laser products used for construction tasks such as alignment, surveying, or positioning. These lasers are limited to Class 3R (formerly 3a) emission limits for visible lasers (0.4 to 0.7 µm) and Class 1 output for other lasers.

Construction Laser Operator.—Individual who has received appropriate training for safe use of construction lasers and is also qualified to operate such lasers by his/her employer per OSHA’s 29 CFR 1926.54.

Continuous Wave Laser.—A laser that emits for more than 0.25 seconds.

Diffuse Reflection.—Change of the spatial distribution of a beam of radiation when it is reflected in many directions by a surface or a medium.

Fail Safe Interlock.—An interlock where the failure of a single mechanical or electrical component of the interlock will cause the system to go into, or remain in, a safe mode (i.e. shuttered or depowered).

Federal Aviation Authority (FAA)

Food and Drug Administration (FDA)

Glenn Research Center (GRC)

Health and Safety Plan (HaSP)

Irradiance.—Radiant power incident per unit area upon a surface, expressed in watts-per-square-centimeter. It is used to characterize a CW laser. Synonym: Power density.

Laser.—Acronym for “Light Amplification by Stimulated Emission of Radiation”; a source of intense, monochromatic, coherent, directional beam of optical radiation.

Laser Controlled Area.—An area containing one or more lasers where the activity of personnel is subject to control. Within this area, potentially hazardous beam exposure is possible.

Laser device— Either a laser or a laser system.

Laser Generated Air Contaminants (LGAC)

Laser Safety Committee (LSC)

Laser Safety Committee Chairperson (LSCC)

Laser Safety Officer (LSO)

Laser Safety Review Board (LSRB)

Laser System.—An assembly of electrical, mechanical, and optical components that include a laser.

Laser User and Laser Operator.—Used interchangeably as a person who uses a laser or laser system.

Laser User Requirements.—Actions, tools, and equipment deemed necessary for safety and to monitor biological effects of laser use.

Legacy Sign. — Any ANSI Z136.1 sign from obsoleted revisions. Continued use of these legacy signs is permitted as long as they do not create confusion or generate a communication hazard.

Maximum Permissible Exposure (MPE).—The level of laser radiation to which a person may be exposed without hazardous effect or adverse biological changes in the eye or skin.

National Aeronautics and Space Administration (NASA)





Nominal Hazard Zone (NHZ).—The space within which the level of the direct, reflected, or scattered radiation during normal operation exceeds the applicable MPE. Exposure levels beyond the NHZ are below the appropriate MPE level.

NASA Procedural Requirement (NPR)

Occupational Health Branch (OHB)

Occupational Safety and Health Administration (OSHA)

Optical Density (O.D.).—Logarithmic expression for the attenuation produced by an eye protection filter.

Original Equipment Manufacturer (OEM)

Radiant exposure.—Surface density of the radiant energy received, expressed in units of joules-per-centimeter squared (J/cm2). It is used to characterize a pulsed laser.

Safety and Health Division (SHeD)

Shall.—Indicates a requirement that is necessary to meet the standards of protection currently in effect.

Should.—Indicates a recommendation that can be applicable.

Specular Reflection.—Reflections from shiny surfaces.

Ultraviolet (UV)



Title: Laser Safety Program Document No.: GLM-QS-1800.1.13 Rev.: E

This is a non-normative appendix intended to provide examples of current and legacy laser signage.

GLP 1800.1.13 Printed copies are uncontrolled and May Not reflect current information. Page 23 of 30 http://smad-ext.grc.nasa.gov/shed/pub/ohpm/ohpm-manual.pdf

APPENDIX B.—CURRENT AND LEGACY SIGNAGE

Note: The rationale for utilization of legacy signage is to limit the turn-over and cost of purchasing new signage with every revision to ANSI Z136.1. When new signage is being purchased, such items should satisfy the current ANSI Z136.1 requirements. Electronic copies and templates of all the current and legacy signage can be acquired by contacting the LSO.

1.0 CURRENT SIGNAGE - ANSI Z136.1-2014

Postings are required for Class 3B and Class 4 Laser Controlled Areas. In addition, facilities with low power lasers propagating in free space may be posted per the LSO/LSCC. See Section 6.5 for further details.

1.1 Class 2, Class 2M, and Class 3R Posting—CAUTION (Figure B.1.1 & Figure B.1.2)

• A CAUTION sign • Top pane background is yellow with black lettering. • A sunburst in the left hand pane. • Right hand pane shall consist of:

− Class 2 and Class 3R: • “Class 2 [3R] laser in Use” • “Do not stare into beam”

− Class 2M: • “Class 2M laser in Use” • “Do not stare into beam or view directly with optical instruments”

• Laser parameters including: − Lasing Medium (Laser Type) − Wavelength − Output Power (Energy/Pulse, PRF, Average Power if appropriate)

Figure B.1.1.—ANSI Z136.1-2014 Class 2 CAUTION Sign

Figure B.1.2.—ANSI Z136.1-2014 Class 3R CAUTION Sign






1.2 Class 3B and Class 4 Posting—WARNING (Figure B.1.3 & Figure B.1.4)

Note: A Class 4 Warning sign should be used when class 4 laser has output power less than or equal to 1kW or equivalent level of hazard exists from a multi-pulse laser system. The LSO will determine whether a WARNING or DANGER sign is appropriate.

• A WARNING sign • Top pane background is orange with black lettering. • A sunburst in the left pane • The right hand pane should consist of

− “Class 3B [Class 4] Laser Controlled Area” − “Avoid eye or skin exposure to direct or scattered radiation.”

• For lower power Class 3B: “Laser Radiation – Avoid direct eye exposure to beam”” − “Do not enter when light is illuminated.”

• Required eye protection should be listed. • Laser parameters including:

− Lasing Medium (Laser Type) − Wavelength − Output Power (Energy/Pulse, PRF, Average Power if appropriate)

Figure B.1.3.—ANSI Z136.1-2014 Class 3B WARNING Sign

Figure B.1.4.—ANSI Z136.1-2014 Class 4 WARNING Sign

1.3 Class 4 Posting—DANGER (Figure B.1.5)

Note: A Class 4 Danger sign should be used when class 4 laser has output power greater than 1kW or equivalent level of hazard exists from a multi-pulse laser system. The LSO will determine whether a WARNING or DANGER sign is appropriate.

• A DANGER sign. • The top pane background shall be red with white lettering. • A sunburst in the left pane • The right hand pane should consist of :

− “Class 4 Laser Controlled Area” − “Avoid eye or skin exposure to direct or scattered radiation.” − “Do not enter when light is illuminated.”

• Required eye protection should be listed.






• Laser parameters including: − Lasing Medium (Laser Type) − Wavelength − Output Power (Energy/Pulse, PRF, Average Power if appropriate)

Figure B.1.5.—ANSI Z136.1-2014 Class 4 DANGER Sign

2.0 LEGACY SIGNAGE - ANSI Z136.1-2007 & ANSI Z136.1-2000 & OSHA Signage

2.1. Class 2, Class 2M, Class 3a Posting—CAUTION (Figure B.2.1 & Figure B.2.2)

Note: Caution signage for Class 3a lasers shall only be used for emissions where accessible irradiance does not exceed the MPE based upon a 0.25s exposure for wavelengths between 400nm and 700nm

• Position 1: − Class 2: “Laser Radiation – Do Not Stare Into Beam” − Class 2M: “Laser Radiation – Do Not Stare Into Beam or View Directly with Optical Instruments” − Class 3a: “Laser Radiation – Do Not Stare Into Beam or View Directly with Optical Instruments”

• Position 2: − Laser Type − Wavelength − Pulse length (if appropriate) − Max Output Power (Energy/Pulse, PRF, Average. Power if appropriate)

• Position 3: − “Class 2” / “Class 2M” / “Class 3a”






Figure B.2.1.—ANSI Z136.1-2000/2007 CAUTION Sign

Figure B.2.2.—OSHA Caution Sign

2.2 Class 3R, Class 3a, Class 3B, and Class 4 Posting—DANGER (Figure B.2.3 & Figure B.2.4)

Note: All Class 3a laser emissions that do not meet the criteria in section 2.1 of this Appendix

• Position 1: − Class 3R and Class 3a: “Laser Radiation – Avoid Direct Eye Exposure” − Class 3B: “Laser Radiation – Avoid Direct Exposure to Beam” − Class 4: “Laser Radiation – Avoid Eye or Skin Exposure to Direct or Scattered Radiation”

• Position 2: − Laser Type − Wavelength − Pulse length and frequency (if appropriate) − Max Output Power (irradiance, radiance, energy/pulse, etc.)

• Position 3: − “Class 3R” / “Class 3a” / “Class 3B” / “Class 4”

Figure B.2.3.—ANSI Z136.1-2000/2007 DANGER sign

Figure B.2.4.—OSHA Danger Sign




This is a non-normative appendix intending to provide examples of Facility Interlock Systems


APPENDIX C.—INTERLOCK SYSTEMS

1.0 Introduction to Interlock Systems

This appendix will serve as a non-normative addition to the laser safety chapter. It is intended to provide background information, design and development ideas, and system requirements to any interested party; as well as to serve as reference material when a questions about interlock system arise. As described in section 6.8, these include custom built or commercial off the shelf (COTS) systems which may utilize electrical relays, programmable logic controllers, or other processor based electronics.

A facility interlock system is an engineering control aimed at reducing the possibility of an inadvertent laser beam exposure to an unsuspecting individual. The general concept is if a person enters an area where there is an exposure potential, the laser emissions (or hazard) is eliminated before an exposure can occur. At the GRC there are a multitude of different laser laboratories and configurations requiring interlock systems; ranging from small, single-door labs, to wind tunnels with many access points.

Every interlock system is designed to the specific requirements of the facility; however, every system functions by the same basic principles and thus have a similar set of components. Most system will have, in some form:

• Trigger Switches • A Manual Reset • Interlock Loop(s)

1.1 Trigger Switches

A trigger switch can take several different forms. These include: reed switches, magnetic contacts, physical contact relays, pressure sensor mats, motion detectors, etc. A trigger switch is the device that is attached to an access point that activates the interlock system when its state is changed. If a door is opened, the trigger switch conveys that signal to the control unit which, in turn, eliminates the exposure potential (typically by activating a shutter or eliminating power to the laser). In some facilities the main power is run through a contact relay which only provides an electrically closed connection when the door it is attached too is fully closed. This is functional; however, it is not the optimal arrangement for most laser systems.

1.2 Manual Reset

A manual reset is a required component of every facility interlock system. When a trigger event occurs, a person must manually reset the interlock system before the exposure potential can reinitiate, (e.g., shutter open, laser start lasing, etc.). This requirement is typically accompanied by an administrative procedure to investigate the trigger event and to ensure there will not be a potential exposure to personnel when the laser is reactivated. (See Section 4.0 for more information on associated administrative controls).

When the situation arises that a legacy facility interlock system does not have a manual reset the LSCC may allow continued operation as long as a manual reset feature of the laser system itself (or an additional external source) is incorporated into the interlock system.

1.3 Interlock Loop

An interlock loop is a common feature amongst simple interlock systems. This puts all (or a portion of) the trigger switches in series. The idea is if any of the trigger switches open, the loop is opened, resulting in a tripped interlock system. This method allows for simplified circuitry, simplified installation, and reduced costs. One pitfall of this serial connection method is in the limited bypass functionality. Typically, the bypass will be installed in a way that bypasses the entire loop. The concerns with this are discussed in section 3.3. Additionally, feedback information on what access point was opened is not easily captured. For smaller facilities, with limited interlock infrastructure requirements, this method is efficient and effective. For larger scale facilities with more complex interlock infrastructure requirements, a shift to parallel communication occurs usually through means of a PLC or other computer based control system; which allows for increased control, modification ability, ease of investigating trigger events.






2.0 Types of Interlock Systems

2.1 Non-Defeatable Interlocks

A non-defeatable interlock system is typically simpler and less expensive than more elaborate interlock systems. Non-defeatable means that the system cannot be bypassed (or ‘defeated’) temporarily to allow facility entry/egress. This is the ANSI-preferred type of interlock system because it does not rely on an associated administrative control, or additional curtain barriers. As a research facility, non-defeatable systems are frequently non-viable options due to their inherent limitations.

2.2 Defeatable Interlocks

The need of a qualified operator to bypass an interlock circuit temporarily in a controlled manner is critical to many research facilities on at the GRC. Such a bypass feature is used in tandem with an administrative control in order to minimize potential hazards from temporarily bypassing the interlock circuit. When possible, it is preferable that the room/laser configuration provide for laser safe environment to an individual entering the controlled area. Otherwise, these administrative controls should include:

- Alerting nearby personnel of his/her intent to enter or exit the lab - Ensure that nobody will be exposed above the MPE by entering or exiting the lab - Ensure person entering has the appropriate PPE. e.g. laser protective eyewear - Requirement that the person defeating the interlock be a competent person (Qualified Operator

listed on the laser safety permit for the lab) or be escorted by a competent person

3.0 Facility Interlock System Requirements

A facility interlock system has three standard functional requirements. First, the interlock system must fail in a safe mode; otherwise known as ‘fail safe’ so that the laser system remains in a depowered (or shuttered) state after a trigger event until the interlock system is manually reset. Second, the interlock system must have a manual reset, which requires that the laser operator takes a deliberate physical action to re-enable beam emission. Third, for a defeatable interlock system, the bypass feature must be isolated to the intended access-point.

3.1 Fail Safe

Laser interlock systems are a physical control measure with the intent of eliminating a potential exposure hazard. In the case of a trigger event, such as a lab door being opened, the exposure potential is mitigated (by either killing power, or shuttering the laser). If the system does not fail in a safe mode, as soon as the door closed the laser system would begin lasing again. The potential exposure hazard still remains to the occupant who entered or to any operators inside. In order to eliminate this issue, all facility interlock systems must remain in a depowered (or shuttered) state after said trigger event. Before the laser can begin lasing again, an operator must manually reset the system.

3.2 Manual Reset

The manual reset feature is a physical control to prevent lasing after an interlock trigger event. Every facility interlock system is required to have a manual reset. Most OTS units will have a ‘RESET’ button directly on the control unit or primary user interface. After a trigger event, while the shutter is closed or lasing disabled, the manual reset must be engaged to reactivate lasing. BEFORE resetting the Interlock System, an investigation should be performed to determine the cause of the trigger event as well as re-verifying the laser controlled area is void of non-essential personnel. This process typically mimics the initial start-up procedure.






Figure C.3.1.—Example Of Laser Facility Layout

3.3 Isolated Bypass Features

When a bypass feature is installed, that feature is isolated to a specific access-point. Here is an example (Figure C.3.1): Given a lab with 2 doors, DOOR A and DOOR B, on opposite sides of the facility. Each door has a defeatable trigger switch attached to it. If a person bypasses Door A the door will be able to be opened freely for the next 30 seconds. If a person bypasses DOOR B the door will also be able to be opened freely for 30 seconds. However; if a person pressed the Bypass button on DOOR A and another individual inadvertently opened DOOR B the interlock system would trigger and immediately secure the beam. Many facilities on Lab only have one defeatable interlock and do not have to worry about isolation; however, there are facilities that do require special attention here. PLC based systems are easily modified to accommodate bypass isolation requirements. Some of the older facilities’ systems as well as many COTS systems do not provide this functionality.

Non-Isolated Bypass Feature Isolated Bypass Feature

Figure C.3.2.—Non-Isolated Bypass Feature Example

Figure C.3.3.—Isolated Bypass Feature Example

A global bypass system forces all access points out of the interlock loop. Facility interlock systems of this configuration need to be reconfigured to accommodate bypass isolation.

Isolated bypass features allows for a single access point to be removed from the interlock loop.






An additional bit of hardware can be added to any interlock system to isolate access-point defeat ability. A bypass isolation module can be created by actuating a relay that connects the input and output connections of the trigger switch for the access-point for a desired amount of time. This is illustrated in figure C.3.4. The LSO has a demonstration unit that provides an example of this on a small scale. The module is intended to fit all forms of interlock systems. In order to accomplish this, the relay that actually bypasses the trigger switch is not included in the module. This relay would be a function of the interlock’s control voltage. Some systems run at high voltage, some at low voltage, and some on open or closed connections. The module itself can consist of a low voltage timer relay, a push button, a few LEDs, and a small relay. The small relay would control the feeder signal to the relay bypassing the trigger switch at the access point.

4.0 Associated Administrative Controls

Periodically the laser operator should verify proper operation of the facility interlock system. As such, engineering controls are only effective if they are operating properly. An entire system check should be performed annually. A faulty engineering control presents an additional hazard to those hazards already present. Take for example a laser interlock system where an illuminated ‘Do Not Enter’ sign does not light up due to a burned out bulb, or faulty electrical connections. This indicator, which normally prevents bystanders from entering an active laser controlled area, now suggests to people that the room is safe to enter. In this scenario, the bystander opens the door, and the door trigger switch should eliminate the laser emission; however, the experiment is halted and potentially ruined. A second scenario, would be an interlock system with a trigger switch at a door that has seized in a ‘closed’ configuration. In this situation, the interlock control system will see the door as closed and satisfy the logical requirements for operation. When a bystander opens said door, the interlock system does not recognize it and the laser emission is not terminated.

After an interlock system has been triggered, the cause should be identified. Depending on complexity of system, this can range from checking the control interface to see which interlock trigger switch was activated and going physically going to look at it, to performing a complete sweep of the controlled area. This administrative control serves the purpose of re-securing the controlled area as well as provide the operator an opportunity to close any trigger switch that is open.

Figure C.3.4.—Simplified Interlock Circuit Diagram

Figure C.3.5.—Simplified block diagram of bypass isolation module


Laser Safety Program - Glenn Research Center · 6.1.3 Other Training ... 6.9.6 NASA Laser Safety Review Board (LSRB) ... mechanisms may be employed in atypical situations.

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