BASS 2019 - Evaluating Surface Contamination James Kapin, MPH, CIH www.actenviro.com [email protected]619-990-5955 1 How Clean is Clean? Evaluating Removable Indoor Contamination James Kapin, MPH, CIH Manager of EM Services ACTenviro www.actenviro.com [email protected]619-990-5955 BASS 2019 - Evaluating Surface Contamination 1 ABC Shooting Range • 20,000 ft2 indoor shooting range – Operated for 15 years – Converting to Daycare/Pre-School • What are we concerned about? • What do we need to do? BASS 2019 - Evaluating Surface Contamination 2
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BASS 2019 - Evaluating Surface Contamination
James Kapin, MPH, CIHwww.actenviro.com [email protected] 619-990-5955 1
Items to Consider at Contaminated Facilities:• What are the chemicals of concern?
• Who is likely to be affected
• What action (if any) need to be taken to characterize contamination?
• What actions (if any) should be taken to remove contamination (clean, demo, etc.)
• What actions (if any) should be taken to evaluate decontamination effectiveness?
• What regulations (if any) apply?
• HOW CLEAN IS CLEAN???– (there are several different approaches!)
BASS 2019 - Evaluating Surface Contamination 8
BASS 2019 - Evaluating Surface Contamination
James Kapin, MPH, CIHwww.actenviro.com [email protected] 619-990-5955 5
How Clean is Clean:
“Hazardous Waste” Approach
The Hazardous Waste Approach• Apply regulatory hazardous waste values to
measured levels of surface contamination.– TTLC, STLC
– RCRA TCLP
– RCRA listed (e.g. F003)
• The good news:– We know these numbers!
– We have a clear regulatory framework (or do we?)
– This what we do!
– Decon activities frequent driven by environmental regulators
BASS 2019 - Evaluating Surface Contamination 10
BASS 2019 - Evaluating Surface Contamination
James Kapin, MPH, CIHwww.actenviro.com [email protected] 619-990-5955 6
If all you have is a hammer…..
BASS 2019 - Evaluating Surface Contamination 11
Everything looks like a nail!
The Hazardous Waste ApproachUnfortunately:
• Haz waste standards do not apply!– Is it waste! Is entire item contaminated, or just the surface?
– Haz Waste standards(i.e. TCLP) can only be used for haz waste determination
– (and don’t get me started about mis-use of F codes!)
• Cannot convert µg/wipe to µg/kg!– Mass per unit area cannot convert to mass per unit volume (or mass) without
more assumptions!
– Weight % of contaminant on wipe is NOT representative of weight % on substrate!
• OELs in mg/m3 (or ppm) cannot be converted (directly) to m2 (or ft2 or 100cm2)!
BASS 2019 - Evaluating Surface Contamination 12
BASS 2019 - Evaluating Surface Contamination
James Kapin, MPH, CIHwww.actenviro.com [email protected] 619-990-5955 7
How Clean is Clean:
“Zero Tolerance” Approach
• Methamphetamine Contaminated Property Cleanup Act of 2005(AB 1078)– CA HSC 6.9.1 Section 25400.16
• Established (among other items) a re-occupancy level of 0.1 µg/100cm2
– Based on LOD
– No background
– Not “natural
• Any Problems?– We’ll come back to this!
Scenario #1
BASS 2019 - Evaluating Surface Contamination 14
BASS 2019 - Evaluating Surface Contamination
James Kapin, MPH, CIHwww.actenviro.com [email protected] 619-990-5955 8
How Clean is Clean:
“Comparative” Approach
Scenario #2 • Wave Solder (leaded solder)
• 8 CCR 5198 (h)(1) –– “All surfaces shall be maintained as free as
practicable of accumulations of lead”
– ???
• “Comparative” standard– Removable contamination compared to
“clean” areas
– Applies to Pb, As, Cd and other metals
• Intended to protect workers
BASS 2019 - Evaluating Surface Contamination 16
BASS 2019 - Evaluating Surface Contamination
James Kapin, MPH, CIHwww.actenviro.com [email protected] 619-990-5955 9
Problems with “Occurrence” Stds.
• Can be poorly defined
• What is the “dose”?
• Can be overly protective
• May not be protective enough?
• “Occurrence” approaches focus on Hazard
– Are there any risk-based approaches?
BASS 2019 - Evaluating Surface Contamination 17
How Clean is Clean:
“Regulatory” Approach
BASS 2019 - Evaluating Surface Contamination
James Kapin, MPH, CIHwww.actenviro.com [email protected] 619-990-5955 10
DOE Berylium Standard• Berylium:
– Strong & Light
– X-ray Transparent, Neutron Reflector/ Moderator
– Highly Toxic - CBD
• DOE 10 CFR Part 850 CBD Prevention– “housekeeping” (internal) level = 3 µg/100cm2
– “release” (public) level = 0.2µg/100cm2
• ”Empirical” levels:– Achievable; didn’t seem to cause problems at relevant facilities e.g.
Rocky Flats
• No exposure scenario modeling or similar
BASS 2019 - Evaluating Surface Contamination 19
HUD Lead Levels
• Guidelines for the Evaluation and Control of Lead-
Based Paint Hazards in Housing (2012 Edition)
– Bare floor = 40 µg/ft2 = 4.3 µg/100cm2
– Explicitly residential
• Only applicable to Pb
BASS 2019 - Evaluating Surface Contamination 20
• Based on blood lead levels of
exposed children
– “Kind of” risk-based
BASS 2019 - Evaluating Surface Contamination
James Kapin, MPH, CIHwww.actenviro.com [email protected] 619-990-5955 11
How Clean is Clean:
“OEL Based” Approach
Scenario #3 – Fab Facilities• Use wide variety of potential hazards:
– Corrosives, Reproductive hazards (photoresists
– Metals
• Many sites used an “IH-based” approach– Arsenic TLV = 0.01 mg/m3
– At 20 m3/day, “allowable” exposure is 0.2 mg
– Can be used as maximum contamination for a given area (typically 100 cm2).
– “Allowable” As contamination is 0.2 mg/100 cm2
• Incorporated into OSHA Tech. Manual (2014)
• OELs apply to inhalation – can this be used for other routes?
BASS 2019 - Evaluating Surface Contamination 22
BASS 2019 - Evaluating Surface Contamination
James Kapin, MPH, CIHwww.actenviro.com [email protected] 619-990-5955 12
Cal/OSHA MBOCA Std.
• Cal-OSHA established wipe sample level for MBOCA (4,4'-Methylenebis(2-Chloroaniline)) in 8 CCR 5215(c)(2)(C)– "Accessible surfaces which employees are likely to contact
…shall not exceed 100 µg MBOCA per 100 cm2 of surface.”
– “… the average of at least five wipe samples shall be used; if one sample exceeds the mean by a factor of 10 or more, it will be rejected as not being representative.”
• Allegedly the 100 µg/100 cm2 derived from PEL (10 µg/m3) * 10 m3.
BASS 2019 - Evaluating Surface Contamination 23
Scenario #4 – Solar Cell Mfg.
• Cadmium Telluride (CadTel) process
– Significant mfg benefits, Can be significantly dirty!
• BNL Alternative IH-based approach
– BNL IH75190 2011 Surface Wipe Sampling
Procedure
• “Housekeeping”, “Release” levels for many
metals
– Widely used for internal guidance and facility decon
BASS 2019 - Evaluating Surface Contamination 24
BASS 2019 - Evaluating Surface Contamination
James Kapin, MPH, CIHwww.actenviro.com [email protected] 619-990-5955 13
The 2011 BNL Approach:
BASS 2019 - Evaluating Surface Contamination 25
• Levels for metals set by ratio:
–𝐷𝑂𝐸 𝑅𝑒𝑙𝑒𝑎𝑠𝑒 𝐿𝑒𝑣𝑒𝑙
𝑂𝑆𝐻𝐴 𝐵𝐸 𝑃𝐸𝐿=
𝑀𝑒𝑡𝑎𝑙 𝑅𝑒𝑙𝑒𝑎𝑠𝑒 𝐿𝑒𝑣𝑒𝑙
𝑀𝑒𝑡𝑎𝑙 𝑃𝐸𝐿 𝑜𝑟 𝑇𝐿𝑉 𝑖𝑛 µg/m3
–0 .2µ𝑔/100𝑐𝑚2
2µ𝑔/𝑚3 = 0.1 (𝑛𝑒𝑣𝑒𝑟𝑚𝑖𝑛𝑑 𝑡ℎ𝑒 𝑢𝑛𝑖𝑡𝑠!)
– Metal Release Level = TLV or PEL in µg/m3 * 0.1 (per 100cm2)
• FTSS = Fraction Transferred from Surface to Skin (unitless fraction)
• CSL = Contaminant Surface Load (:g/cm2 )
• SA = Surface Area (cm2 /event)
• FQ = Frequency of hand to mouth events (events/hr)
• SE = Saliva Extraction factor (unitless fraction)
• ET = Exposure Time (hr/d)
• BW = Body Weight (kg)
• RfD – Reference Dose– EPA, 2001a. Science Advisory Council for Exposure. Policy Number 12 on Recommended Revisions to
the Standard Operating Procedures (SOPs) for Residential Exposure Assessments. Rev. February 22, 2001
• “For carcinogens, LADD is calculated by summing daily doses (PDR) over ages 1 to 31 and then averaging over a lifetime of 70 years.”
• “Dose rates were estimated based on a number of assumptions—for example, the fraction of dust residues that can be transferred to the skin, daily skin loads, mouthing behaviors for different age groups, and dissipation of surface loading over time.”
BASS 2019 - Evaluating Surface Contamination 28
BASS 2019 - Evaluating Surface Contamination
James Kapin, MPH, CIHwww.actenviro.com [email protected] 619-990-5955 15
Description Notes Units Default
RFd EPA reference dose varies by substance
mg/kg-
day 0.0003
BW Body Weight
EPA Exposure Factors Handbook
(1989) kg 70
SAo Surface Area, expsoed hands
EPA Exposure Factors Handbook
(1989) m2 0.084
MF
Fraction expossed area contacted by
mouth
Risk assess asumption -
conservative
amount/
day 0.5
CE Skin Contact Efficiency Risk assess asumption none 0.5
– 1 part “waste” extracted in 20 parts acid (by weight)
– Assume 100% extraction
• Assume 1 ft2
– 196 kg/m2 = 7.3 kg/ft2
– 7.3 kg* 1L/kg*20 = 147L acid
• Contaminant on 1 ft2
– 900 cm2/ft2 / 100 cm2/wipe = 9 wipes
– 9 wipes x 100 µg/wipe = 900 µg = 0.9 mg
– 0.9 mg/147L = 0.006 mg/L
– Not Hazardous waste based on Cd TCLP
BASS 2019 - Evaluating Surface Contamination 35
How Clean is Clean:
More Problems!
BASS 2019 - Evaluating Surface Contamination
James Kapin, MPH, CIHwww.actenviro.com [email protected] 619-990-5955 19
Sampling Strategy
• Where to sample,
• How to Sample
• Sampling Strategy & Number of samples
– Random?
– Authoritative or targeted sampling??
• Level of confidence needed or scrutiny
• Degree of hazard
BASS 2019 - Evaluating Surface Contamination 37
Sampling Strategy Problems!!!• Lack of Clear Guidance on Sampling Strategy
• Back to Basics (lets define our terms):– “Sample” - portion of population, used to make inferences
about the population• Validity of inferences assumes samples represent population
• Accuracy & Precision require adequate # of “representative samples”
– “Population” must have well-defined physical and/or temporal boundaries.
• Does the level of indoor surface contamination constitute a “population”?
BASS 2019 - Evaluating Surface Contamination 38
Or
BASS 2019 - Evaluating Surface Contamination
James Kapin, MPH, CIHwww.actenviro.com [email protected] 619-990-5955 20
EPA SW 846 Chapter 9• Simple random sampling adequate for randomly
heterogeneous populations– a suitable # of samples is randomly selected from the
population.
• Stratified random sampling used for non-random heterogeneity– the population stratified to account for non-randomness
• Also– Systematic Grid Sampling
– Random Sampling w/in Grid
• Which works for us?
BASS 2019 - Evaluating Surface Contamination 39
Factors to Consider
• Design and layout of area to be
sampled• (Localized spill or systematic contamination)
• “Random” or “authoritative sampling
• Statistical evaluation (if appropriate)
– Number of samples to be taken
BASS 2019 - Evaluating Surface Contamination 40
BASS 2019 - Evaluating Surface Contamination
James Kapin, MPH, CIHwww.actenviro.com [email protected] 619-990-5955 21
Sampling Locations to Consider• Work areas where contaminant is handled
• Exterior of work area of containment equipment
• Floor of work area
• Access to work area
• Surfaces (Counter tops) and equipment in work area
• Equipment
• “Clean” area – e.g adjacent office or break rooms
• Storage Areas
BASS 2019 - Evaluating Surface Contamination 41
Sampling Strategy Influences Results!
• Size of the sampling area (100 cm2, 1 ft2)
• Location of the sampling (where they are taken)
• Number of samples (1-4)
BASS 2019 - Evaluating Surface Contamination 42
BASS 2019 - Evaluating Surface Contamination
James Kapin, MPH, CIHwww.actenviro.com [email protected] 619-990-5955 22
Effect of Sample Area
• Small Sample areas
may “miss”
contamination
• Larger samples areas
(or higher #)
increase likelihood
of finding
contamination
BASS 2019 - Evaluating Surface Contamination 43
Area to evaluate – approx. 1 m2
Location of
contamination
HUD and other Guidance• HUD Guidelines for the Evaluation and Control of Lead-
Based Paint (2012 Edition) Chapter 15– For common areas, one floor sample for every 2,000 ft2 and one floor
sample outside
• San Diego DEH Site Assessment and Mitigation (SAM) Manual, Chapter 5, Site Investigation– References SW 846 - Stockpiles assumed to have non-homogeneous
distribution
– Stockpiles <10 yd3 - minimum 2 random samples
– 10 -20 yd3 - min 3 random samples
– 20-100 yd3 - min 4 random samples
– 100-500 yd3 – min 1 random sample per each 25 yd3
• Are these applicable?BASS 2019 - Evaluating Surface Contamination 44
BASS 2019 - Evaluating Surface Contamination
James Kapin, MPH, CIHwww.actenviro.com [email protected] 619-990-5955 23
• Guidelines for the Evaluation and Control of Lead-Based Paint Hazards in Housing (2012 Edition)– http://portal.hud.gov/hudportal/HUD?src=/program_offices/healthy_homes/lbp/hudguidelines
• EPA Risk Assessment Guidance and Tools– http://www.epa.gov/risk_assessment/guidance.htm
• SEMI S12-0211: Environmental, Health and Safety Guideline for Manufacturing Equipment Decontamination– http://ams.semi.org/ebusiness/standards/SEMIStandardDetail.aspx?ProductID=211&DownloadI