Chapter 33: Hazardous Materials - Fundamentals of Fire Fighter

Fundamentals of Fire Fighter Skills, Third Edition
Chapter 33: Hazardous Materials: Response Priorities and Actions
Chief Concepts
Exposures can consist of people, property, structures, or the environment. The number of
exposures is determined by the location and the amount of progress made in protecting
the exposures.
The two main protective actions utilized to protect human exposures are evacuation and
With evacuation, the role of the fire fighter is to assist in the physical evacuation of
residents to a safe area or shelter such as a school. Potential shelters should be determined
during preincident planning.
Shelter-in-place involves keeping residents near a hazardous area safe by keeping them in
a healthy atmosphere, usually inside structures and with the ventilation system turned off.
The toxicity of the hazardous material is a major factor in deciding whether to evacuate
or shelter-in-place. The more toxic the substance, the more likely evacuation will be
Responders are required to take appropriate steps to monitor the atmosphere for potential
hazards. Monitoring priorities should include radiation, corrosive vapors, oxygen levels,
combustibility, and final toxicity. Radiation monitoring is conducted using a Geiger
counter. Oxygen levels and combustible levels are typically monitored with the use of a
two, three, four, or five-gas monitor. Other specialized chemical monitors can be used to
detect individual chemicals.
The search and rescue process is more complicated in a hazardous materials incident than
in a structure fire. Before beginning search and rescue operations, all emergency response
personnel must first recognize and identify when hazardous materials may be present.
After this is accomplished, the IC must evaluate the conditions. If hazardous materials are
present, the IC must determine whether hazardous materials technicians can safely enter
the hot zone to perform search and rescue operations.
The IC determines which offensive or defensive actions are to be taken and who will take
those actions on the scene of a hazardous materials incident.
Confinement is the process of attempting to keep the hazardous materials on the site or
within the immediate area of release. Containment refers to actions that stop the
hazardous material from leaking or escaping.
Fires associated with a hazardous materials incident should be addressed with great
caution because some hazardous materials react violently if water is applied. Most
flammable and combustible liquid fires can be extinguished through the application of
Incidents involving pressurized-gas cylinders may involve fires or releases of the
cylinders’ contents. Some materials stored in pressurized cylinders may be flammable,
others may be flammable and toxic, and still other gases may pose asphyxiant hazards to
personnel. If a pressurized-gas cylinder is leaking, responders should take these actions:
• Evacuation of all nonessential personnel
• Rescue of injured people by crews equipped with the necessary PPE
© 2014 Jones & Bartlett Learning
Corrective action to minimize the leak or at least minimize exposure to people
and equipment
• Assurance that all necessary resources are available for the final resolution of the
• Firefighting action
• Decontamination
• Written documentation and critique
Hazardous materials control activities include the following:
• Absorption/adsorption—Techniques for holding a hazardous material to make
collection and disposal easier.
• Diking—Emplacement of an impervious material to form a barrier that will keep
a hazardous material from entering an area.
• Damming—Includes complete dams, overflow dams, and underflow dams. A
complete dam completely stops the flow of materials through a channel. An
overflow dam uses piping to trap the material at the base of the dam. An
underflow dam allows water to flow through piping under the dam and collects
the hazardous material at the top of the dam.
• Diversion—Redirection of the flow of a liquid from an area.
• Retention—Creation of an area to hold hazardous materials.
• Dilution—Addition of water or another liquid to weaken the strength or
concentration of a hazardous material.
• Vapor dispersion—Lowering the concentration of vapors by spreading them out.
• Vapor suppression—Controlling fumes or vapors that are given off by certain
• Identify and isolate a remote shut-off valve—Many systems have a way to
remotely shut down a system.
After all of the factors have been considered, the IC may decide that the hazardous
materials incident cannot be handled without unnecessary risks and that all personnel
should withdraw.
The recovery phase of a hazardous materials incident occurs when the imminent danger
to people, property, and the environment has passed or is controlled, and clean-up begins.
During this phase, state and federal agencies may become involved in cleaning up the
site, determining the responsible party, and implementing cost-recovery methods.
The recovery phase in large-scale incidents can last for days, weeks, or even months and
may require resources and equipment beyond those available to local responders.
If a hazardous materials incident involves potential criminal or terrorist activity,
responders must notify law enforcement and appropriate federal agencies. Specific
activities should be implemented to ensure safety, such as isolating the scene.
© 2014 Jones & Bartlett Learning