Value of High Flow Fire Extinguishers for Class B Hazards NFPA 10-2013 High Flow Requirements Overview Dave Beranek, FESSCO Fire Equipment Sales & Service.

Value of High Flow Fire Extinguishers for Class B

Hazards

NFPA 10-2013High Flow Requirements Overview

Dave Beranek, FESSCO Fire Equipment Sales & Service Co.

OSHA Part 19101910 Subpart L- Fire Protection 1910.157 (d) (1)

“Portable fire extinguishers shall be provided for employee use and selected and distributed based on the classes of anticipated workplace fires and on the size and degree of hazard which would affect their use”.

Fire Extinguisher Training

The training of employees in the proper use of all portable fire extinguishers is a federally mandated requirement that is found in CFR29 (OSHA Regulations). Either ‘live’ or simulated training suffices.

29 CFR 1926 OSHASubpart J Welding & Cutting 1926.352 When practical, move objects to be welded away

from flammables, etc. If it can’t be moved, contain the heat, sparks and slag.

Welding or cutting shall not be done in the presence of flammable paints, etc.

Suitable fire extinguishing equipment shall be immediately available in the work area and shall be maintained in a state of readiness for instant use.

“additional personnel shall be assigned to guard against fire… Such personnel shall be instructed as to the specific anticipated fire hazards and how the fire fighting equipment provided is to be used”.

Fire Classification Pictograms

Classification of Fires

Class “A” Fires occur in ordinary combustible material; wood, cloth and paper. “Leaves an Ash”.

Class “B” Fires occur in the vapor/air mixture over the surface of flammable liquids. A “smothering” or combustion-inhibiting effect is necessary to extinguish these fires.

Class “B” Fires

Types of Class “B” Fires: Combustible liquids & gases. Flammable liquids & gases. Greases

Class “C” Fires

Refers to the “conditions” under which the extinguisher can be used. Means that the user will not become the conductor in an electrical charge.

Class “C” refers to the source of the ignition, not to the fuel.

There is no true “Class C” fire; the fires are either Class “A”, Class “B” or Class “D”.

Class “K” Fires

Fires in cooking media (vegetable or animal fats or oils). Belong in kitchens, suppresses the flammable grease vapors. The extinguisher agent should be compatible with the fixed kitchen suppression system.

Class “D” Fires

Occur in combustible metals such as; magnesium, titanium, zirconium, sodium, lithium and aluminum. Normal extinguishing agents can’t be used on these fires and can cause intensification of the fire. These include dry chemical and especially water as it will explode due to chemical reaction between water & fuel.

Protection of People & Assets

Reduce injury to employees Reduce “down time”. Protect valuable assets. Can the extinguishing agent

itself cause collateral damage?

Fire Theory Overview

For many years Fire triangle (heat, fuel & oxidizing agent (air) was taught.

Current theory recognizes the interconnecting chemical reactions (referred to as a chemical chain reaction). This is the fourth leg: now a “tetrahedron”.

Now we have four methods of extinguishment.

Four Methods of Extinguishment

Remove the heat. Agents that do this: Water Foam LVS or specialized liquids Some gases including 3M Novec

1230 Restaurant fire systems liquid

agents

Four methods of extinguishment

(continued)

Remove the fuel. Agents that do this: Foams that separate the liquid fuel

from the flammable vapors via their “securing actions”. Shut off the valve that supplies the fuel. You can also dilute the fuel to a point below its flammability limit.

Four methods of extinguishment

(continued)

Remove the oxygen. The agents that do this: CO2 displaces the oxygen. Concerns

with this? Clean agents that reduce the oxygen

level so it does not sustain a flame, yet is breathable. Remember; it is the vapors that burn (when the fuel is heated above it’s ignition temperature), not the flammable liquid (drop a match in a bucket of gasoline).

Four methods of extinguishment

(continued)

Interrupt the Chemical reaction. Agents that do this: All dry chemicals Halons Clean agents

Extinguishing Agents

Dry Chemicals interrupt the chain reaction Commonly used in hand and wheeled

units As fuel burns (oxidizes), free radicals

are released. Free radicals are attracted to and combine with the fine dry chemical particles. The finer the particles, the more effective they are (when attached to the free radicals) because of increased surface area.

Mono Ammonium Phosphate (MAP) Based Dry Chemicals

Common in areas needing ABC (all purpose) protection

Works on the more difficult (deep seated embers) Class A fires by melting at 300 deg. F, leaving a residue that coats the embers and suppresses (excludes) oxygen.

Color coded yellow. Color of the font on some labels indicate the agent inside.

Sodium Bicarbonate Based Dry Chemicals

Color coded blue Often times referred to as “training

chemical”. Uses magnesium stearate as a water

repellent. Less effective than other agents. Is for Class B and C fires.

Potassium Bicarbonate Based Dry Chemical

Commonly called ‘Purple K”, color coded pale violet.

Best dry chemical for B and C Fires. Uses silicone as a coating to make it

water repellent and free flowing.

Dry Powders

Common “Class D” combustibles (with lower melting points) such as sodium, potassium, magnesium and aluminum, lithium and those with lower melting points such as titanium, zirconium and zinc. Salt/resin based agents melt, forming a crust-like surface and smother metals in the 1200 Deg. F range. Agent names; MET-L-X, LITH-X and MET-L-KYL are common.

Dry Powders(continued)

CAUTION: do not expose halogenated agents (Halon, Halotron, FE-36, etc.) to the high heat common to Class D fires. It creates hydrofloric acid which can be lethal.

Be aware of incompatibilities of various extinguishing agents such as water, ABC dry chemical, foam, etc.

Water Most common, least expensive agent for Class

A combustibles. Cools as well as knocks down flame. The volume of water present as a liquid is expanded by a factor of 1700 times in converting it to steam. This can alter the vapor phase concentration of the fuel so it is either below the lower flammability limit (LFL) or above the upper flammability limit (UFL).

Water is a conductor, so streaming water does not have a C rating. New water mist products do have a C rating. Heat transfer (absorption) is much higher with misting technology, but the discharge range is lessened.

Cautions in Using Dry Chemicals

UL listing specifies that only that manufacturers dry chemical be used in their extinguisher.

Cannot mix dry chemicals from different manufacturers when recharging.

Can’t mix MAP (slightly acidic) agent with bicarbonate agents (mildly alkaline). When combined, CO2 and H2O are produced. H20 is the bane of dry chemical. Causes “caking”.

Ratings of Extinguishers

UL established an alpha-numeric designation so an operator can determine the size and type of fire on which that extinguisher is appropriate to use.

Caution: the rating of an extinguisher does not always indicate the effectiveness! Longer discharge time required to achieve rating means less agent discharged over a longer period of time.

View high flow vs. reg. flow video

Extinguisher Rating Example

A rating of 4-A:40-B:C indicates a novice can expect to extinguish a Class A fire 4.3 m x 4.3 m, a Class B fire 40 sq. ft., and it can also be used to extinguish fires in the presence of energized electrical equipment.

Extinguishers will now have a UL/ULC rating; called the bi-national standard.

Class ‘A’ UL/ULC Tests Panel Fires vary in size from around 8

ft. square to 24 ft. square. Uniform , prescribed panel size, weight, gallons of fuel oil applied, and total pounds of excelsior (fire accelerant) used.

Crib fire is of a specific dimension wood crate, fought from 3 sides, prescribed pre-burn time.

Larger crib or panel= greater rating View 6A panel test video

Class ‘B’ Ratings

Test uses 2” of flammable heptane in a metal pan, size of pan varies based on ratings desired. The Class “B” rating represents the # of square ft. of fire area that the novice can expect to extinguish. This is always 40% of the fire that the expert operator at UL can extinguish. Larger area = greater ratings.

View Class ‘B’ rating test video

Class “B” Ratings(continued)

Criteria are minimum effective discharge time,

pan size in sq. ft.

# gallons of heptane.

Ratings for a portable extinguisher range from 1-B to 640-B.

Class “C” Ratings

No test fires required for this rating at UL. This is a “GO or NO-GO” rating.

The extinguishing agent need only be a non-conductor of electricity.

There are no numerical rating applied to Class C ratings.

NFPA 10-2007-2013 Three Major Changes

1. Mandates the minimum size & flow rate of an extinguisher must meet for (3) specific Class B fire hazards.

2. All employees must be trained.

3. Phase out of obsolete stored pressure fire extinguishers manufactured before 1984.

NFPA 10-2007 New High Flow

RequirementsMinimum size & flow of extinguishers used for three types of fires:Pressure firesObstacle FiresThree dimensional fires

Extinguishers for Pressurized Flammable Liquids & Gases

Fires

Now specifies extinguisher size & flow rate based on 3 types of fires. Size must be 10 lb. or greater and a discharge rate of 1 lb. or more per second.

Play 3 panel comparison video An addition that goes beyond the

prior recommendations based on a simple spill fire (6.3.1.1).

Pressure Fires

Involve a gas or flammable liquid that is being released under pressure from a pipe, hose, valve, pump, cylinder, tank, or other storage or transport device.

Examples: fuel pumps, compressed gases, vehicle or machinery having flammable hydraulic fluids, piped gases, parts cleaners, broken flanges, etc.

Play raised turbo fire video.

Obstacle Fires

Involve Class ‘B’ flammable liquids spilled on a flat surface where a solid object creates a barrier within the perimeter of the burning liquid.

Examples: drum storage areas, areas under machinery, vehicle engines, flammable liquid storage cabinets.

Three Dimensional Fires

Involve a flammable liquid in motion and usually include both horizontal and vertical surfaces. Usually, a liquid drips down a vertical surface to a horizontal surface below.

Examples: process machinery, vehicle fueling areas, hydraulic machinery, vehicle engines, flammable storage cabinets, transformers, storage tanks & drum storage racks, etc.

Extinguisher Discharge Rates

Vary by size and rating. High flow products from Ansul range from just over 1 lb. per second (minimum req’d for this standard) to 8 lb. per second discharge rate for wheeled units.

Fire fighting principle; the more agent you put on the fire, the faster it will extinguish.

The higher volume of dry chemical in the air will settle into areas that a “direct” stream of dry chemical cannot reach. Allows better results when fighting pressure, obstacle and three dimensional fires.

Hazard Assessments

Follow the flow of flammables from the dock to disposal. Consider less flammable alternatives.

Each time the liquid is transferred from one vessel to another is a potential for fire. Comply with OSHA handling & storage requirements of flammables (bonding/grounding, storage, etc.).

Refer to MSDS’s files to identify where flammables are being used in your facility.

Be aware of flammables being brought into the facility by contractors, etc. Look for placards, labels.

Identify where all flammable gas cylinders are used and moved to during operations.

Consult your MSDS to find flammables in your facility. Are those areas protected properly with fire protection?

Flammable Storage Cabinets

Look for quantities of 5 gal. or more indicating a high hazard area needing high flow extinguishers. Represents a 3 dimensional hazard.

Signs & Flammable Placards

Look for flammable liquid placards, indicating presence of flammables. Look for the “yellow” (cabinets, waste containers, pipe markers, etc.) when auditing an area.

Look for flammable gases in high pressure cylinders.

This would indicate a flammable gas under pressure and be an area that requires a high flow extinguisher.

Classification of HazardsNow partially based on quantity,

combustibility, rate of heat release

5.4.1.1 Light (Low) Hazards- … where the quantity and combustibility of Class A combustibles and Class B Flammables is low and fires with relatively low rates of heat release are expected… with the total anticipated quantity of Class B flammables present is less than 1 gallon in any room or area.

Classification of Hazards(continued)

5.4.1.2 Ordinary (Moderate)Hazards… where the quantity and combustibility of Class A combustible materials and Class B flammables is moderate and fires with moderate rates of heat release are expected… and the total quantity of Class B flammables typically expected to be present is from 1 gallon to 5 gallon in any room or area.

Classification of Hazards(continued)

5.4.1.3 Extra (High) Hazards

Where the quantity and combustibility of Class A combustible material is high or where high amounts of Class B flammables are present and rapidly developing fires with high rates of heat release are expected… and a total quantity of Class B flammables expected to be present is more than 5 gallon in any room or area.

Pressurized Fires

5.5.1.1.1 Pressurized Flammable Liquids & Gases Involves liquid or gas being

released under pressure from a hose, pipe, flange, tank, etc. Examples; propane storage tanks, fuel pumps, compressed gas cylinders, high pressure hydraulic cylinders, flanges.

Use your judgment, can the fuel be shut off?

5.5.2 Three-Dimensional Fires

Involve flammable liquid in motion (gravity, etc.) and usually includes both horizontal & vertical surfaces as well as the pooling of liquids.

5.5.4 Obstacle Fires

Involves flammable liquid on a horizontal surface where a solid object creates a barrier within the perimeter of the burning liquid. Example; a spill on the floor around a solid object.

NFPA 10-2007 Summary

A good addition to the existing standard. Fills the gap left by “spill fire” hazard recommendations.

Emphasizes new classification of hazards, training and tools to fight those fires. You would be surprised at the type and size of fire you can successfully fight with the right tools and training.

29 CFR 1926 OSHASubpart J Welding & Cutting 1926.352 When practical, move objects to be welded away

from flammables, etc. If it can’t be moved, contain the heat, sparks and slag.

Welding or cutting shall not be done in the presence of flammable paints, etc.

Suitable fire extinguishing equipment shall be immediately available in the work area and shall be maintained in a state of readiness for instant use.

“additional personnel shall be assigned to guard against fire… Such personnel shall be instructed as to the specific anticipated fire hazards and how the fire fighting equipment provided is to be used”.

Any Questions?