Chapter 12

Mission-Specific Competencies: Product

Control

Objectives: Operations Level Responders Assigned Mission-Specific Responsibilities (1 of 3)

• Describe and identify the control options available to operations levels responders.(NFPA 6.6.3.1, p. 254–255)

• Describe and identify the control options available for flammable liquid and flammable gas incidents. (NFPA 6.5.2.1(1)(2), p. 254–255)

• Describe the purpose, equipment, and precautions associated with control options.(NFPA 6.6.3.1, 6.6.3.2, p. 255–267)

Objectives: Operations Level Responders Assigned Mission-Specific Responsibilities (2 of 3)

• Describe the applicability and characteristics of aqueous film-forming foam, alcohol-resistant concentrates, fluoroprotein foams, protein foams, and high-expansion foams. (NFPA 6.6.4.1(1)(2), p. 265)

• Identify the location and describe the use of emergency remote shut-off devices on MC 306/DOT 406, MC 307/DOT 407, and MC 331 cargo tanks containing flammable liquids or gases. (NFPA 6.6.4.1(4)(5), p. 262–263)

Objectives: Operations Level Responders Assigned Mission-Specific Responsibilities (3 of 3)

• Describe the recovery phase, and the transition from emergency to clean-up.(NFPA 6.6.4.2, p. 267–268)

Introduction (1 of 3)

• Confinement– Process of attempting to keep hazardous

material within immediate area of release– Damming or diking material, or suppressing

vapor with appropriate type of foam

Introduction (2 of 3)

• Containment– Actions that stop the hazardous material from

leaking or escaping container– Patching or plugging a breached container– Righting an overturned container to stop slow

leak

Introduction (3 of 3)

• When considering control option, evaluate:– Maximum quantity of material that can be

released– Likely duration of incident without intervention

Control Options

• Sometimes no action is the safest course of action. – The situation may be extreme. – Responders cannot be properly protected. – Product will evaporate quickly, cool down, or

solidify.

Absorption (1 of 2)

• Spongy material (e.g., soil or loose absorbents) or specially designed spill pads are used to soak up a liquid hazardous material.

• Contaminated mixture of absorbent material and chemicals are collected and disposed of together.

• Effective only on flat surfaces

Absorption (2 of 2)

• Process does not change chemical properties of substance; only collects substance for containment

• Challenging because personnel must be in close proximity to spilled material

• Adding material to a spilled product adds volume to the spill.

Adsorption

• Contaminant adheres to surface of added material (e.g., silica or activated carbon) rather than combining with it.

• This process can generate heat, which should be considered.

Damming• Used when liquid is flowing in a natural channel or

depression and its progress can be stopped by blocking the channel

Complete Dam

• Placed across a small stream or ditch to completely stop flow of material through channel

• Used only in areas where stream or ditch is dry and amount of material needed to be controlled is small

Overflow Dam• Used to contain materials heavier than

water• Dam base is built up to level that holds

back flow of water.• PVC pipe or hard suction hose is installed

at a slight angle to allow water to flow “over” the released liquid.

• Heavier material is trapped at low level at base of dam.

Underflow Dam• Used to contain materials lighter than

water• Piping is installed near bottom of dam so

water flows “under” dam.• Materials floating on the water accumulate

at top of dam area.• Must have sufficient pipes and hoses to

allow enough water to flow past dam without overflowing over top of dam

Diking

• Placement of selected material, such as sand, dirt, loose absorbent, or concrete, to form a barrier that will keep a liquid hazardous material from entering an unwanted area or to hold material in specific location

• Material used to control hazard must not react adversely with spilled material.

Dilution

• Addition of water or another substance to weaken the strength or concentration of hazardous material (typically a corrosive)

• Used only when identity and properties of hazardous material are known

• Water applied to dilute hazardous material may simply increase total volume.

• Take extreme caution.

Diversion• To redirect flow of liquid away from an

endangered area to an area where it will have less impact

• Existing barriers may be effective way to divert liquids away from storm drains or other unwanted destinations.

• Dirt berms, spill booms, plastic tarps filled with sand, dirt, or clay

• Not as permanent as a dike; constructed quickly

Retention

• Creating a defined area to hold hazardous materials

• Material is held until clean-up contractor can recover it.

• Sometimes, diversion technique is required to guide spilled liquid into retention basin.

Remote Valve Shut-Off (1 of 3)

• Many chemical processes, and many piped systems that carry chemicals, provide a way to remotely shut down a system or isolate a leaking fitting or valve.

• Many types of cargo tanks have emergency remote shut-off valves.

Courtesy of Glen Rudner

Remote Valve Shut-Off (2 of 3)

• MC306/DOT406 cargo tanks carry flammable and combustible liquids and Class B poisons.– Remote shut-off valves located at front of

cargo tank on driver’s side or rear of cargo tank on passenger side

• MC-307/DOT-407 cargo tanks carry chemicals transported at low pressure.– Outfitted with many safety features similar to

those found on MC306/DOT406 cargo tanks

Remote Valve Shut-Off (3 of 3)

• MC-331 cargo tanks carry compressed liquefied gases. – Remote shut-off

valves located at both ends of tank, internal shut-off valves, rotary gauge depicting product pressure, and top-mounted vents

Courtesy of Rob Schnepp

Vapor Dispersion (1 of 2)

• Lowering concentration of vapors by spreading vapors out

• Vapors can be dispersed with:– Hose streams set on fog patterns– Large displacement fans– Other types of mechanical ventilation found in

fixed hazardous materials handling systems

Vapor Dispersion (2 of 2)

• Vapor dispersion with fans or fog stream should be attempted only after hazardous material is safely identified and in weather conditions that will promote diversion away from populated areas.

Vapor Suppression• Controlling fumes or vapors that are given

off by certain materials, particularly flammable liquids, in an attempt to prevent their ignition

• Hazardous material covered with foam or other material or temperature of material is reduced.

• Responders must choose foam designed to work in certain situations.

Aqueous Film-Forming Foam• Used at 1%, 3%, or 6% concentration• Designed to form blanket over spilled

flammable liquids to suppress vapors or on actively burning pools of flammable liquids

• Usually biodegradable• Applied by in-line foam eductors, foam

sprinkler systems, and portable or fixed foam proportioning systems

Alcohol-Resistant Concentrates

• Properties similar to AFFF, but formulated so that alcohols and other polar solvents will not dissolve foam

Fluoroprotein Foam

• Protein products mixed with synthetic fluorinated surfactants.

• Used on fires or spills involving gasoline, oil, or similar products

• Rapidly spread over fuel, ensuring fire knockdown and vapor suppression

• Resistant to polar solvents such as alcohols, ketones, and ethers

Protein Foam

• Made from hydrolyzed proteins along with stabilizers and preservatives

• Stable and have good expansion properties

• Resistant to reignition when used on Class B fires or spills involving nonpolar substances

High-Expansion Foam

• Used when large volumes of foam required for spills or fires in warehouses, tank farms, and hazardous waste facilities

• Expansion accomplished by pumping large volumes of air through small screen coated with foam solution.

• “Dry” foam—due to large amount of air in the foam

Foam Application (1 of 3)

• Foam concentrates (other than high-expansion foam) should be gently applied or bounced off another adjacent object so they flow down across liquid and do not directly upset burning surface.

Foam Application (2 of 3)

• Rain-down method – Directing stream in air over material and

letting foam gently fall onto surface of liquid• Roll-in method

– Bouncing stream directly into front of spill area and allowing it to gently push forward into the pool

Foam Application (3 of 3)

• Bounce-off method – Using object to deflect foam stream and

letting it flow down onto burning surface

Recovery Phase (1 of 3)

• When imminent danger to people, property, and environment has passed or is controlled, and clean-up begins

• Local, state, and federal agencies involved– Cleaning up site– Determining responsible party– Implementing cost-recovery methods

Recovery Phase (2 of 3)

• Can go on for days, weeks, or even months and may require large amounts of resources and equipment

• Sometimes clear transition between emergency phase and clean-up phase– Decision made by incident commander

Recovery Phase (3 of 3)

• Other times, initial responders perform both emergency response and clean-up.

• Includes completion of records necessary for documenting incident

Courtesy of Captain David Jackson, Saginaw Township Fire Department

Summary (1 of 4)

• When considering a control option, a variety of factors must be evaluated, such as the maximum quantity of material that can be released and the likely duration of the incident if no intervention is made.

• Sometimes the situation is so extreme, or the proposed action is so risky, that it may be prudent to create a safe perimeter and let the problem stabilize on its own.

Summary (2 of 4)

• Control techniques or options generally aim to contain, redirect, or lower the concentration of the hazardous material involved and/or to prevent the ignition of flammable liquids or gases.

• Responders can employ a variety of product-control options, such as absorption, diversion, damming, diking, or isolating a leak with remote shut-off valves.

Summary (3 of 4)

• Special foams can help both in vapor suppression actions and in extinguishment of fires associated with flammable liquid releases.

• Responders should be aware of the location of emergency shut-off valves at fixed facilities and on the various types of cargo tanks typically found in their response area.

Summary (4 of 4)

• The recovery phase may last for days or months and aims to return the exposure area to its original condition and return the facility or mode of transportation to the responsible party.