Chapter 35

Hazardous Materials Responder Health and Safety

Objectives: Hazardous Materials Operations Level

• Discuss the hazards of fire smoke.• Discuss the effects of carbon monoxide

and hydrogen cyanide on the body. • Describe methods for treating smoke

inhalation. • Discuss post-fire detection and monitoring

needs.

Objectives: Hazardous Materials Operations Level

• Discuss the purpose of detection devices at fire scenes.

• Discuss the various technologies available for fire-ground detection and monitoring.

• Discuss general fire-ground monitoring principles and practices.

Introduction • Combustion process liberates fire gases

and particulates.• Smoke often kills people before the flames

reach them.• Signs and symptoms of breathing smoke:

– Headache– Nausea– Dizziness– Fatigue

Introduction

• Fire agencies are increasingly mandating self-contained breathing apparatus (SCBA) use for longer periods.

• The environment invades the body when the breathable air supply is lost or interrupted.

Courtesy of Rob Schnepp.

Introduction • Chapter goals:

– Provide an overview of fire smoke hazards– Highlight link between smoke exposure and

chronic health effects• Smoke impacts every

aspect of the lives of those who work in or around it.

Courtesy of Rob Schnepp.

Introduction

• Questions to ask– Do crews wear SCBA until the building is

clear of smoke?– Have you established action levels for the

gases you are monitoring during post-fire detection and monitoring?

– Are personnel trained to understand detection and monitoring and to use the related technology appropriately?

Introduction

• Questions to ask – Are rapid intervention crews (RICs) located so

close that they are breathing smoke prior to being called into service?

– Is the command post located in drift smoke?– Does your prehospital care system have a

treatment protocol for smoke inhalation?– Is the local receiving hospital ready to treat a

significant smoke-related illness?

Harmful Components of Fire Smoke

• Carbon monoxide • Ammonia• Hydrogen chloride• Sulfur dioxide• Hydrogen cyanide• Carbon dioxide

Courtesy of Rob Schnepp.

Harmful Components of Fire Smoke

• Oxides of nitrogen• Formaldehyde• Acrolein• Polycylic aromatic hydrocarbons• Soot

Smoke Production

• Depends on– Chemical makeup of burning material– Temperature of combustion process– Influence of ventilation (oxygenation)

• Smoke is a collection of– Particulates– Superheated air– Gaseous chemical compounds

Synthetic Manufacturing and Construction Materials

• Extensive use affects fire behavior and smoke production.

• Synthetic substances ignite and burn fast, causing rapidly developing fires and toxic smoke.

Synthetic Manufacturing and Construction Materials

• Polyurethane mattress foam– Parent substances break down and bond with

each other when exposed to heat, creating new compounds.

– Some are irritants.• Hydrogen chloride and ammonia

– Some are acutely toxic when inhaled.• Carbon monoxide and cyanide compounds

Synthetic Manufacturing and Construction Materials

• Combustion liberates– Soot (visible)– Gases (invisible)

• Smoke is not only one thing– It is a dynamic, multifaceted mixture of gases

and particulates that changes from minute to minute at any fire.

Polycyclic Aromatic Hydrocarbons (PAHs)

• Commonly found in fire smoke• Probable or possible human carcinogen• Over 100 identified and categorized• Found in

– Vehicle exhaust– Tobacco smoke– Smoke generated from fires

Polycyclic Aromatic Hydrocarbons (PAHs)

• Can exist as particle or gas

• Also generated when grilling food

• May bond with soot, resulting in dermal and inhalation exposures

• Believed to be immunosuppressant

Courtesy of Rob Schnepp.

Polycyclic Aromatic Hydrocarbons (PAHs)

• Examples of PAHs include– Anthracene– Benzopyrene– Methylchrysene– Phenanthrene– Pyrene

Polycyclic Aromatic Hydrocarbons (PAHs)

• Contaminants to structural firefighting protective gear

• Dirty structural firefighting protective gear is:– Unhealthy– Likely to contribute to sustained exposure to

the fire long after leaving the scene

Carbon Monoxide and Hydrogen Cyanide

• Acutely toxic • Present to some degree in nearly all fires• Clinical interventions are available to

reverse adverse health effects of exposure.

Carbon Monoxide and Hydrogen Cyanide

• Findings of a study of toxic substances in smoke– Cyanide and carbon monoxide are important

determinants of smoke inhalation-related morbidity and mortality.

– Cyanide concentrations are directly related to probability of death.

Carbon Monoxide and Hydrogen Cyanide

• Findings of a study of toxic substances in smoke– Cyanide poisoning may be more predominant

than carbon monoxide poisoning as cause of death in fire victims.

– Cyanide and carbon monoxide may potentiate the harmful effects of one another.

Carbon Monoxide and Hydrogen Cyanide

• Hydrogen cyanide can incapacitate a victim, preventing escape from fire environment.– Increases exposure to toxic by-products of

combustion

Cyanide and Aerobic Metabolism

• Aerobic metabolism– Red blood cells carry

oxygen to and from cells.– Oxygen enters the

mitochondria of each cell.– Mitochondria convert

nutrients into ATP.

© Jones & Bartlett Learning.

© Jones & Bartlett Learning.

Cyanide and Aerobic Metabolism

• Cyanide compounds interfere with aerobic metabolism.– Prevent oxygen from entering mitochondria– Shuts down aerobic metabolism– Cells switch to anaerobic metabolism, which

produces toxic by-products that destroy the cell.

Carbon Monoxide• One of the most common

industrial hazards• Colorless and odorless• Produced during

incomplete combustion• Affects oxygen-carrying

capacity of red blood cells, causing hypoxia

© Jones & Bartlett Learning.

Smoke Inhalation• Very complex and challenging patient

presentation• Patient outcomes influenced by

– Extent and duration of smoke exposure– Amount and nature of toxicants in smoke– Degree of thermal burns to skin and lungs– Quantity/size of inhaled particulates (soot)– Patient’s age – Underlying medical conditions

Treating Smoke Inhalation • No nationwide standard protocol• Often boils down to supportive care

– Monitoring vital signs– Providing high-flow oxygen– Establishing intravenous (IV) lines– Performing advanced airway management

techniques– Cardiac monitoring– Rapid transport

Treating Smoke Inhalation

• Until the underlying cause of asphyxia is reversed at the cellular level, normal oxygenation is not possible– Requires administering antidote (oxygen)

to restore body’s ability to use oxygen– High-flow oxygen should be administered

for all cases of smoke inhalation.

Treating Smoke Inhalation

• Treatment for cyanide poisoning requires– Different kind of antidote– Oxygen administration

• Two types of antidote kits– Lilly kit– Cyanokit

Treating Smoke Inhalation • Lilly kit (Taylor or Pasadena kit)

– Also called cyanide antidote kit (CAK)– Contains amyl nitrate, sodium nitrate, and sodium

thiosulfate– Nitrates convert hemoglobin to methemoglobin to

attract cyanide– Restores cell’s ability to take in oxygen– Thiosulfate bonds with cyanide, rendering it less

harmful– Can cause blood pressure to drop

Treating Smoke Inhalation

• Cyanokit (hydroxocobalamin)– Relatively benign with minimal side effects– Benign, minimal adverse effects– Can be administered without first verifying

presence of cyanide

Treating Smoke Inhalation

• Consult NFPA 473, Section 6.4, “Mission-Specific Competencies Advanced Life Support (ALS) Responder Assigned to Treatment of Smoke Inhalation Victim,” as a reference source for treating smoke-related illness and injury

Post-Fire Detection and Monitoring

• No best practice for detection and monitoring in the fire environment

• Atmospheric monitoring technology and devices should be– User-friendly– Durable– Cost-effective– Easy to maintain

Post-Fire Detection and Monitoring

• Targeting certain gases– Broadly representative of airborne environment– Not an exact indicator of the presence, absence,

or concentration of other gases or particulates• Wearing SCBA

– Gold standard of respiratory protection– Best way to reduce possibility of inhalation

exposures

Post-Fire Detection and Monitoring

• Three primary uses for detection devices– Rescue response (including confined space)– Building collapse and trench rescue– Carbon monoxide detector responses

Why Use Detection Devices at the Fire Scene?

• No single device detects all fire gases and particulates in fire smoke.

• Initial detection seeks to determine– What substances you want to detect and/or

monitor– At what concentrations they pose a risk of

exposure

Why Use Detection Devices at the Fire Scene?

• National Institute for Occupational Safety and Health (NIOSH) levels for chemicals in the workplace– Immediately dangerous to life and health (IDLH)

• Requires breathing apparatus or withdrawal– Short-term exposure limit (STEL)

• 15-minute exposure; limit four times a day– Recommended exposure limit (REL)

• 10-hour exposure

Why Use Detection Devices at the Fire Scene?

• Most common detection method involves single-gas or multi-gas detection devices.– Environment considered IDLH if levels are at

or above 1200 ppm.– REL is safer end point for detection and

monitoring.– Next step is to widen the focus and evaluate

for multiple gases with a multi-gas meter or multiple technologies.

Fire Scene Detection and Monitoring Technologies

• Three technologies are commonly used– Electrochemical sensors– Photoionization detector (PID) sensor– Colorimetric tubes

Electrochemical Sensors• Contain chemical reagent that reacts with

target gas, resulting in a meter reading.• Typical sensors include

– Oxygen– Hydrogen cyanide– Carbon monoxide– Hydrogen sulfide– Ammonia– Chlorine Courtesy of Rob Schnepp.

Electrochemical Sensors• Concerns

– React to other gases– Can be easily overwhelmed and will max out

with regard to their readings– Fail to the zero point

• Before use, devices must be– Calibrated properly– Bump tested

• Reaction times of sensors vary

Photoionization Detector (PID)• Stand-alone unit or multi-gas meter• Ultraviolet light ionizes gases in sensor• Detects materials such as

– Benzene– Acetone– Toluene– Ammonia– Ethanol– Butane

Courtesy of Rob Schnepp.

Photoionization Detector (PID)

• Primarily detects organic materials• Most common inorganic material detected

is ammonia.• Will not detect

– Carbon monoxide – Hydrogen cyanide– Compounds such as natural gas

Photoionization Detector (PID)

• Reaction time of 1 to 2 seconds• Most have protective filter

– Keeps out some particulate material

– Must replace frequently at fire scene

• Water resistant, not waterproof Courtesy of Rob Schnepp.

Colorimetric Tubes

• Detect specific substances and/or confirm readings of other technologies

• Identify presence and/or levels of known gas or vapor and unidentified substances

• Designed to detect chemical families but can be set to detect a specific chemical

Colorimetric Tubes

• Air moves through tube by use of piston-style pump or bellows pump.

• Easy to use• Require little preparation• Single-use only• Pump is reusable.

Courtesy of Rob Schnepp.

Fire Scene Detection and Monitoring Practices

• Detection devices not necessary during active interior structural firefighting – High heat, particulates, and steam or

water detrimental to instruments• Assume environment is IDLH.

– Wear firefighting personal protective equipment (PPE), including SCBA.

• Limit air monitoring during active firefighting to exterior operations.

Fire Scene Detection and Monitoring Practices

• Start detection and monitoring with exterior evaluation of footprint of fire.– Work inward toward crews.– Fire gas production stops only when all

substances involved in fire are cooled below point they decompose and off-gas.

– Initiate interior monitoring when all visible particulate has been ventilated.

Fire Scene Detection and Monitoring Practices

• Fire investigators should evaluate environment prior to beginning work.

• Ventilation practices can change and influence interior atmosphere.– Gasoline-powered positive

pressure ventilation (PPV) fans can raise carbon monoxide levels above the REL. Courtesy of Rob Schnepp.

Fire Scene Detection and Monitoring Practices

• Detection at the fire scene not an exact science due to– Limitations of instrumentation– Dynamic nature of fire scene– Narrow view of using only one or two gases

as indicators of airborne environment

Fire Scene Detection and Monitoring Practices

• Cumulative smoke exposures over the course of a career can be dangerous.

• Recommendations– Wear your SCBA for longer periods of time at the

fire scene.– Keep your structural firefighting protective gear

clean.– Shower after working at a fire.– Get regular health evaluations and cancer

screenings.

Summary

• When asked about fire fatalities, fire fighters typically observe that smoke kills people before the flames ever get to them, and fire death statistics prove likewise.

Summary

• Most people identify carbon monoxide as the main harmful component of fire smoke. – Less often acknowledged are compounds

such as ammonia, hydrogen chloride, sulfur dioxide, hydrogen sulfide, hydrogen cyanide, carbon dioxide, the oxides of nitrogen, formaldehyde, acrolein, polycyclic aromatic hydrocarbons, and soot.

Summary

• Studies performed in Paris, France, and Dallas County, Texas, focused on carbon monoxide and hydrogen cyanide specifically because they are acutely toxic, present to some degree in nearly all fires, and have clinical interventions available to reverse the adverse health effects of the exposure.

Summary

• Nationwide, there is no standard protocol for treating smoke inhalation, leaving paramedics and other prehospital care providers with limited guidance or training to properly care for smoke inhalation victims.

Summary

• Many fire agencies are investing in technologies for detecting toxic gases at the fire scene without a clear understanding of the mission, the limitations of the devices, or what it means to check to see if the building is clear and, more commonly, when it is safe to remove SCBA.

Summary • NIOSH establishes safe levels for

chemical exposures in the workplace; however, the values are for average worker exposure and can be only estimated for the rigors of firefighting.

• Equipment such as electrochemical sensors, photoionization detectors, and colorimetric tubes can all be used to monitor conditions at a fire scene.

Summary

• Regardless of which instrument is selected, hazardous materials responders should develop a defined and systematic strategy for the use of detection devices.