Chapter 4

Estimating Potential Harm and Planning a Response

Objectives: Awareness Level Personnel (1 of 3)

• Describe resources to determine the scope of a hazardous materials/WMD incident. (NFPA 4.4.1, p. 86–88)

• Describe how to report the size and scope of the incident. (NFPA 4.4.1(8)(9)(10), p. 91)

• Identify protective actions. (NFPA 4.4.1(6)(7)(11), p. 89–90)

• Identify skin-contact hazards encountered at hazardous materials/WMD incidents. (p. 92)

• Describe how to plan initial actions within the scope of awareness personnel. (NFPA 4.4.1(12), p. 92–93)

Objectives: Awareness Level Personnel (2 of 3)

• Describe the potential for secondary attacks/devices. (p. 93–94)

• Identify the purpose, advantages, and limitations of the following items (NFPA 4.4.1.[5]):– Street clothing and work uniforms (p. 96)– Structural firefighting protective clothing (p. 96)– High-temperature–protective clothing and

equipment (p. 96) – Chemical-protective clothing and equipment (p.

98-100)

Objectives: Awareness Level Personnel (3 of 3)

• Discuss the levels of hazardous materials/WMD personal protective equipment (PPE). (p. 98–100)

Objectives: Operations Level Responders (1 of 3)

• Describe how to estimate the potential harm or the severity of a hazardous materials/weapons of mass destruction (WMD) incident. (NFPA 5.1.2.2, 5.2.4, p. 84–86)

• Describe resources to determine the scope of a hazardous materials/WMD incident. (NFPA 5.1.2.2, 5.2.4, p. 91)

• Describe exposure protection. (NFPA 5.2.4, 5.3.1, p. 89–90)

• Describe resources available for determining the concentrations of a released hazardous material.(NFPA 5.2.4, p. 91–92)

Objectives: Operations Level Responders (2 of 3)

• Identify skin-contact hazards encountered at hazardous materials/WMD incidents. (NFPA 5.3.3(2), p. 92)

• Describe how to plan an initial response. (NFPA 5.3.1, 5.3.2, p. 92–94)

• Describe the potential for secondary attacks/devices. (NFPA 5.3.1(4), p. 93–94)

• Describe personal protective equipment (PPE) used for hazardous materials/WMD incidents, as well as the care and maintenance of PPE provided by the AHJ. (NFPA 5.3.3(2), 5.4.4(6)(7), p. 94–103)

Objectives: Operations Level Responders (3 of 3)

• Identify the purpose, advantages, and limitations of the following items:– Structural firefighting protective clothing (p. 96)– High-temperature–protective clothing and equipment

(p. 96)– Chemical-protective clothing and equipment (p. 96-

97)• Discuss the importance of respiratory protection in a

hazardous materials/WMD incident. (NFPA 5.3.3(1), p. 100–103)

• Describe the importance of having a plan in place to decontaminate a victim. (NFPA 5.3.2, 5.3.4, p. 103–104)

Introduction

• First response priority: Ensure your own safety while operating at the scene.– Arrive in a safe manner.– Ensure you and your crew do not become a

liability.• Next objective: Address the potential life

safety of those affected by the incident.

Estimating Potential Harm or Severity (1 of 2)

• The damage that a hazardous material/WMD will inflict is a function of the physical and chemical properties of the released substance.

Estimating Potential Harm or Severity (2 of 2)

• The following will affect the release parameters and potential health effects of those exposed to the material:– Concentration of hazardous material– Temperature at time of release– Pressure under which substance was

released– Age, gender, genetics, and underlying

medical conditions of exposed persons

Reference Sources

• Two main organizations publish toxicological data used by responders:– American Conference for Governmental

Industrial Hygienists (ACGIH)– Occupational Safety and Health

Administration (OSHA)

Threshold Limit Value (TLV)

• Established by ACGIH• The point at which a hazardous material or

WMD begins to affect a person

Permissible Exposure Limit (PEL) (1 of 2)

• Established by OSHA• The established standard limit of exposure

to a hazardous material• Based on minimum time-weighted

concentration at which 95% of exposed, healthy adults suffer no adverse effects over a 40-hour workweek

Permissible Exposure Limit (PEL) (2 of 2)

• Toxicological values expressed as:– Parts per million (ppm), parts per billion (ppb),

parts per trillion (ppt)– Milligram per cubic meter (mg/m3) for

substances such as fibers and dust

Threshold Limit Value/Short-Term Exposure Limit (TLV/STEL) (1 of 2)

• Maximum concentration of a hazardous material to which a worker can sustain a 15-minute exposure not more than four times daily without experiencing irritation or chronic or irreversible tissue damage

Threshold Limit Value/Short-Term Exposure Limit (TLV/STEL) (2 of 2)

• Minimum one-hour rest period between exposures

• The lower the TLV/STEL value, the more toxic the substance

Threshold Limit Value/Time-Weighted Average (TLV/TWA)

• Maximum airborne concentration of material to which worker can be exposed for 8 hours a day, 40 hours a week, and not suffer ill effects

Threshold Limit Value/Ceiling (TLV-C)

• Maximum concentration of hazardous material to which a worker should not be exposed even for an instant

Threshold Limit Value/Skin

• The concentration at which direct or airborne contact with material could result in possible and significant exposure from absorption through skin, mucous membranes, and eyes

Recommended Exposure Level (REL)

• Value established by NIOSH comparable to OSHA’s PEL and the TLV/TWA

• Measures maximum time-weighted concentration of material to which 95% of healthy adults can be exposed without suffering adverse effects over a 40-hour workweek

Immediately Dangerous to Life and Health (IDLH)

• Atmospheric concentration of any toxic, corrosive, or asphyxiant substance such that it poses immediate threat to life or could cause irreversible or delayed adverse health effects

• Requires the use of self-contained breathing apparatus

Reference

• The Emergency Response Guidebook(ERG) provides a reference for evacuation distances and gives basic action plans.

Exposures (1 of 2)

• The on-scene crew must consider how exposures might be affected.

• Exposures: people, property, structures, or environments that are subject to influence, damage, or injury due to contact with hazardous material/WMD

Exposures (2 of 2)

• The number of exposures determined by:– Location of the incident– Physical and chemical properties of

substance– Progress made in protecting exposures by

isolating release site or taking protective actions

Isolation of the Hazard Area

• One of the first actions that must be taken• Responders and civilians kept safe

distance from the release site• Law enforcement officers posted to create

secure perimeter• If barrier tape is used, must be backed up

by human presence• Always conjoined with denial of entry

Evacuation

• Removal/relocation of individuals affected by approaching release of hazardous material

• Should not require personnel to wear PPE or enter contaminated atmospheres

Sheltering-in-Place

• Temporarily keeping people who are near or in hazardous areas in a cleaner atmosphere, usually inside structures

• Only when population can care for themselves and control the air, and structure can be sealed

Reporting Size and Scope of Incident

• Use information available at scene.• Be as accurate and clear as possible

when communicating.

Determining Concentration of Released Material (1 of 2)

• Concentration: amount of solute in given amount of solution

• Concentrated solution contains large amount of solute.

• Dilute solution contains small amount of solute.

• Natural gas release: Responders may need specialized equipment to determine airborne concentration.

Determining Concentration of Released Material (2 of 2)

• Regarding corrosives, concentration is expression of how much acid or base is dissolved in a solution. – Strength refers to degree of ionization that

occurs in a solution. – Strong acid is strong even in a dilute

concentration.• To measure pH in the field, use litmus

paper (pH paper).

Skin Contact Hazards (1 of 2)

• Responders should not rely on pain or irritation as a warning sign – Some poisons so concentrated that just a few

drops on skin can result in death• Absorption is enhanced by abrasions, cut,

heat, and moisture

Skin Contact Hazards (2 of 2)

• Corrosives will immediately damage skin or body tissues upon contact.– Acids cause skin and respiratory tract burns.– Alkaline materials dissolve fats and lipids that

make up skin tissue (deeper, more destructive burns than acid burns).

Plan an Initial Response• Understand the nature of an incident and

determine a course of action.• Tactical control objectives are actions that

may or may not involve the actual stopping of the leak or release of hazardous material.

• Responders must know:– If material is solid, liquid, or gas – If spill is still in progress or has ceased

Response Objectives

• Measurable, flexible, time sensitive• Several may be developed.

Secondary Attacks and Devices (1 of 2)

• Terrorists who want to injure responding personnel with a secondary device or attack will typically make the initial attack very dramatic to draw responders in close proximity to the scene.

Secondary Attacks and Devices (2 of 2)

• EVADE– Evaluate scene for areas where secondary devices

are likely to be placed.– Visually scan operating areas before providing patient

care.– Avoid touching or moving anything that may conceal

an explosive device.– Designate and enforce scene control zones.– Evacuate victims, other responders, and nonessential

personnel as quickly and safely as possible.

Defensive Actions

• Diking and damming• Stopping the flow of a substance from a

valve or shut-off• Diluting or diverting the material• Suppressing or dispersing vapor

Personal Protective Equipment(1 of 3)

• Determination of which PPE is needed is based on:– The hazardous material involved– The specific hazards present– The physical state of the material

• Selection and use of chemical-protective clothing may have greatest impact on responder health and safety.

Personal Protective Equipment (2 of 3)

• The National Fire Protection Association (NFPA) publishes protective clothing standards for performance of chemical-protective garments.– The NFPA does not “certify” any garments.– Provides guidance on manufacturing quality

and performance standards.

Personal Protective Equipment (3 of 3)

• Consult the OSHA HAZWOPER regulation, 29 CFR 1910.120 – Appendix B offers guidance on which

components should be worn for certain levels of protection, and under which conditions the various levels of protection should be chosen.

Types of PPE (1 of 4)

• Street clothing and work uniforms– Work uniforms can prevent a “nuisance”

powder from coming into direct contact with skin.

• Structural firefighting protective clothing– Includes helmet, bunker coat, bunker pants,

boots, gloves, hood, SCBA, and personal alert safety system (PASS) device

– In some cases, safer than traditional types of chemical-protective clothing

Types of PPE (2 of 4)

• High-temperature–protective clothing and equipment– Shield wearer during short-

term exposures to high temperatures

– Allow fire

© Photodisc

Types of PPE (3 of 4)

• Chemical-protective clothing and equipment– Designed to prevent chemicals from coming in

contact with the body– Time, temperature, and resistance to cuts, tears, and

abrasions are factors that affect chemical resistance of materials.

– Chemical-resistant materials are designed to inhibit or resist the passage of chemicals into and through the material.

– Penetration is the flow or movement of a hazardous material through closures (e.g., zippers), seams, porous materials, pinholes, or other imperfections in the material.

Types of PPE (4 of 4)

• Chemical-protective clothing and equipment (cont’d)– Permeation is the process by which a hazardous

chemical moves through a given material on the molecular level.

– Garment can be a single piece or multiple piece. Vapor-protective clothing offers full-body protection from highly contaminated environments and requires supplied-air respiratory protection devices such as SCBA.

– Liquid splash-protective clothing protects the wearer from chemical splashes.

Chemical-Protective Clothing Ratings (1 of 4)

• Level A– A fully encapsulating garment that completely

envelops both the wearer and the respiratory protection, gloves, boots, and communications equipment

– Used when hazardous material requires the highest level of protection for the skin, eyes, and respiratory tract

– Recommended PPE:• SCBA or supplied-air respirator• Fully encapsulating vapor-protective chemical-resistant suit• Inner and outer chemical-resistant gloves• Chemical-resistant safety boots/shoes• Two-way radio

Chemical-Protective Clothing Ratings (2 of 4)

• Level B– Chemical-protective clothing, boots, gloves, and

SCBA– Used when hazardous material requires a high

level of respiratory protection, but less skin protection

– Recommended PPE:• SCBA or SAR• Chemical-resistant clothing• Inner and outer chemical-resistant gloves• Chemical-resistant safety boots/shoes• Two-way radio

Chemical-Protective Clothing Ratings (3 of 4)

• Level C– Standard work clothing plus chemical-protective clothing,

chemical-resistant gloves, and a form of respiratory protection– Air-purifying respirator (APR) or powered air-purifying respirator

(PAPR)– Used when airborne substance is known, concentration is

measured, criteria for using APRs are met, and skin and eye exposure is unlikely

– Recommended PPE:• Full-face APR• Chemical-resistant clothing• Inner and outer chemical-resistant gloves• Chemical-resistant safety boots/shoes• Two-way radio

Chemical-Protective Clothing Ratings (4 of 4)

• Level D– When the atmosphere contains no known hazard,

and when work functions preclude splashes, immersion, or potential for unexpected inhalation of or contact with hazardous levels of chemicals

– Nuisance contamination (dust) only; never for sites where respiratory or skin hazards are known to exist

– Recommended PPE:• Coveralls• Safety boots/shoes• Safety glasses or chemical-splash goggles• Hard hat

Respiratory Protection (1 of 2)

• NFPA 1994, Standard on Protective Ensembles for First Responders to CBRN Terrorism Incidents – Covers performance of protective garments– Factors in performance requirements of

respiratory protection

Respiratory Protection (2 of 2)

• Class 2: Liquid-splash garment performance with SCBA

• Class 3: Liquid-splash garment performance with APR

• Class 4: Performance requirements for particles and liquid-borne viral protection

Physical Capability Requirements (1 of 2)

• Health and safety program – Pre-employment screening and periodic

medical exams– Treatment plans for acute on-scene illness

and injury – Thorough recordkeeping of all elements of the

program – Mechanism to review the entire process

Physical Capability Requirements (2 of 2)

• Medical surveillance objectives– To determine if individuals can perform duties– To detect changes in body system functions

caused by exposures• Physical exam at least once a year

– Exam based on expected tasks employee may perform

– Conduct health questionnaire– Take x-rays and perform respiratory function test

Positive-Pressure Self-Contained Breathing Apparatus

• Prevents inhalation and ingestion exposures

• Mandatory for fire service personnel

Courtesy of Rob Schnepp

Supplied-Air Respirators

• Positive-pressure air-line respirators• Use an external air source such as

compressor or compressed air cylinder• For extended operations such as

decontamination, clean-up, and remedial work

• Less bulky and weigh less than SCBA, but length of air hose can limit movement

Closed-Circuit SCBA

• Also called “rebreather”• Used when long work periods are required• Exhaled air is scrubbed free of carbon

dioxide, supplemented with oxygen, and “rebreathed” by the wearer

Air-Purifying Respirators (1 of 2)

• Filtering devices or particulate respirators that remove particulates, vapors, and contaminants from air

• Used when type and quantity of contaminants are known and where sufficient oxygen for breathing is available

Air-Purifying Respirators (2 of 2)

• Do not have separate source of air; filter and purify ambient air before inhalation

• Ambient atmosphere must contain minimum of 19.5% oxygen

• Not worn at hazardous materials/WMD incidents until ambient atmosphere has been tested

Powered Air-Purifying Respirators• Similar to APR but include

small fan to help circulate air into the mask

• Advantages – Diminish the work of

breathing – Help reduce fogging in the

mask – Provide constant flow of

cool air across face Courtesy of Rob Schnepp

Decontamination (1 of 2)

• A procedure or plan must be established to decontaminate anyone who becomes contaminated.

• Contamination: the process of transferring a hazardous material from its source to people, animals, the environment, or equipment, that can act as a carrier

Decontamination (2 of 2)

• Decontamination: the physical and/or chemical process of reducing and preventing the spread of contaminants from people, animals, the environment, or equipment involved at hazardous/WMD incidents

© Bill Karrow, Dunkirk Observer/AP Photos

Emergency Decontamination(1 of 2)

• The process of quickly reducing or removing the bulk of contaminants from a victim as rapidly as possible

• Undertaken in potentially life-threatening situations

• Without formal establishment of a decontamination corridor

• Involves removing contaminated clothing and dousing victim with large quantities of water

• More formal, detailed decontamination may follow.

Emergency Decontamination (2 of 2)

• Can easily be accomplished from a fire engine: – Pull a handline, maneuver it into a circle,

throw a tarp over the middle of the circle, and pull a booster line or other small handline.

• Avoid touching contaminated victim and/or entering contaminated environments without protection.

Secondary Contamination• Cross-contamination• Transferring a hazardous material from its source to

people, animals, the environment, or equipment• A contaminated person or object comes into direct

contact with another person or object:– A contaminated person comes into physical contact with another

person– A bystander or responder comes into contact with a

contaminated object from the hot zone– A decontaminated responder reenters the decontamination area

and comes into contact with a contaminated person or object• Hot, warm, and control zones should be established,

clearly marked, and enforced.

Summary (1 of 9)

• The first response priority is to ensure your own safety while operating at the scene.

• Hazardous materials/WMD incident response priorities should be based on the need to protect and/or reduce the threat to life, property, critical systems, and environment.

Summary (2 of 9)

• To have some frame of reference for the degree of harm a substance may pose, responders should have a basic understanding of some commonly used toxicological terms and definitions.

• Gather information from detection and monitoring devices, bystanders, reference sources, and environmental conditions to obtain a clear picture of the incident as a whole.

Summary (3 of 9)

• Exposures can include people, property, structures, or the environment that are subject to influence, damage, or injury as a result of contact with a hazardous material/WMD.

• Immediate protective actions include isolation of the hazard area, denial of entry, evacuation, or sheltering-in-place.

Summary (4 of 9)

• Tactical control objectives include preventing further injury and controlling or containing the spread of the hazardous material.

• Response objectives should be measureable, flexible, and time sensitive; they should also be based on the chosen strategy.

Summary (5 of 9)

• Defensive actions include diking and damming, absorbing or adsorbing the hazardous material, stopping the flow remotely from a valve or shut-off, diluting or diverting the material, and suppressing or dispersing vapors.

• The decision to take action at a hazardous materials/WMD incident should be based on the concept of risk versus benefit.

Summary (6 of 9)

• The type of personal protective equipment required for an incident depends on the material involved, any specific hazards, the physical state of the material, and the tasks to be performed by the operations level responder.

• The selection and use of chemical-protective clothing may have the greatest direct effect on responder health and safety.

Summary (7 of 9)

• The EPA defines four levels of personal protective equipment: Level A (highest level of protection), Level B, Level C, and Level D (lowest level of protection).

• NFPA 1994, Standard on Protective Ensembles for First Responders to CBRN Terrorism Incidents, was developed to address the performance of protective ensembles specific to weapons of mass destruction. It covers three classes of garments: Class 2, 3, and 4.

Summary (8 of 9)

• Respiratory protection is so important that it can be viewed as the defining element of personal protective equipment.

• Medical surveillance is the cornerstone of an effective health and safety management system for responders. Before any personal protective equipment is worn, hazardous materials response personnel should be aware of the physiological stress those garments create.

Summary (9 of 9)

• Even though there should be no intentional contact with the hazardous material involved, a procedure or a plan must be established at every hazardous weapons/WMD incident to decontaminate anyone who accidentally becomes contaminated.