Chapter 31: Hazardous Materials: Awareness and Specialties

Fundamentals of Fire Fighter Skills, Canadian Third Edition

Chapter 31: Hazardous Materials: Awareness and Specialties

Chief Concepts

· To ensure your safety and the safety of your crew, you must be able to recognize a potential hazardous material as soon as possible.

· Many hazardous materials can be recognized by smell, taste, or touch; getting close enough to exercise these senses, however, may expose you to the hazard. The farther you are from the incident, the safer you will be.

· Transport Canada’s TDG regulations employ a system of labels and placards to identify dangerous goods in transit. The ERG is also part of this system and offers a certain amount of guidance for fire fighters operating at a hazardous materials incident.

· Labels, placards, and other markings on buildings, packages, boxes, and containers often enable fire fighters to identify a spilled or released chemical.

· Placards are diamond-shaped indicators (250 mm [10.75 in.] on each side) that must be placed on all four sides of highway transport vehicles, railroad tank cars, and other forms of transportation carrying hazardous materials.

· Labels are smaller versions of placards (100 mm [4-in.] diamond-shaped indicators) and are used on any side of individual boxes and smaller packages being transported.

· Nine chemical families are recognized by the ERG:

1. Class 1—Explosives

2. Class 2—Gases

3. Class 3—Flammable liquids

4. Class 4—Flammable solids, spontaneously combustible materials, and water-reactive substances

5. Class 5—Oxidizers

6. Class 6—Poisons (including blood agents and choking agents)

7. Class 7—Radioactive materials

8. Class 8—Corrosives

9. Class 9—Other regulated materials

· The ERG is a preliminary action guide for hazardous materials incidents. It is divided into four coloured sections:

1. Yellow section—Used when the UN number is known or can be identified.

2. Blue section—Lists chemicals alphabetically by name.

3. Orange section—Contains the emergency action guides.

4. Green section—Organized numerically by UN identification number and provides the initial isolation distances for specific materials.

· The NFPA 704 hazard identification system is designed for fixed-facility use. It uses a diamond-shaped symbol of any size, which is itself broken into four smaller diamonds, each representing a particular property or characteristic: The blue diamond at the nine o’clock position indicates the health hazard posed by the material; the top red diamond indicates flammability; the yellow diamond at the three o’clock position indicates reactivity; and the bottom white diamond is used for special symbols and handling instructions.

· Additional reference sources for hazardous materials include SDSs, shipping papers, and staffed national resources such as CANUTEC. An SDS provides basic information about the chemical makeup of a substance, the potential hazards it presents, appropriate first aid in the event of an exposure, and other pertinent data for safe handling of the material. SDSs may be kept in a three-ring binder or a file cabinet, or a computer system.

· Industries that routinely use radioactive materials include food testing labs, hospitals, medical research centres, biotechnology facilities, construction sites, and medical laboratories. Radioactive materials are not detectable by sight, smell, taste, or other senses. If you have any suspicion that an incident involves radiation, it is necessary to call a hazardous materials team or some other resource with radiation detection capabilities.

· The proper use of PPE and scene control are critical to ensuring the safety of fire fighters, victims, and bystanders.

· TLV exposure guidelines are as follows:

• TLV–TWA is the maximum concentration of a material to which a worker could be exposed for 8 hours a day, 40 hours a week, with no ill effects.

• TLV–STEL is the maximum concentration of a material to which a person can be exposed for 15-minute intervals, up to four times a day, without experiencing irritation or chronic or irreversible tissue damage.

• TLV–C is the maximum concentration of a material to which a worker should not be exposed, even for an instant.

• Threshold limit value–skin is the concentration at which direct or airborne contact with a material could result in possible and significant exposure from absorption through the skin, mucous membranes, and eyes.

• IDLH—An atmospheric concentration of a toxic, corrosive, or asphyxiating substance that poses an immediate threat to life or could cause irreversible or delayed adverse health effects.

· Exposure guidelines are intended to minimize the possibility that either responders or the public will be exposed to hazardous materials or atmospheres that will lead to harm. Exposure guidelines can be used to define the three basic atmospheres at a hazardous materials emergency:

1. Safe atmosphere—No harmful hazardous materials effects exist, so personnel can handle routine emergencies without donning specialized PPE.

2. Unsafe atmosphere—A hazardous material that is no longer contained has created an unsafe condition or atmosphere. A person who is exposed to the material for long enough will probably experience some form of acute or chronic injury.

3. Dangerous atmosphere—Serious, irreversible injury or death can occur in the environment.

· Selecting the appropriate PPE for a hazardous materials incident is a potentially life-saving decision. Adequate PPE should protect the fire fighter’s respiratory system, as well as his or her skin, eyes, face, hands, feet, head, body, and hearing.

· Which type of PPE is required for the incident depends on the activities that the fire fighter is expected to perform.

· The categories of hazardous materials–specific PPE include the following:

• Street clothing and work uniforms (least amount of protection)

• Structural firefighting protective clothing (no chemical protection but protects against abrasion and direct skin contact)

• High temperature–protective equipment (high-temperature protection during short-term exposures)

• Chemical-protective clothing and equipment (e.g., liquid splash–protective clothing and vapour-protective clothing)

· Respiratory protection includes the following:

• SCBA

• SARs—Have an external air source, such as a compressor or storage cylinder

• APRs/PAPRs—Filtering devices

· CPE ratings are as follows:

• Level A protection—Provides the highest level of protection for skin, eyes, and respiration.

• Level B protection—Used when the type and atmospheric concentration of identified substances require a high level of respiratory protection but less skin protection.

• Level C protection—Used when the type of airborne substance is known, its concentration is measured, the criteria for using APRs are met, and skin and eye exposure is unlikely.

• Level D protection—Used when the atmosphere contains no known hazard and when work functions preclude splashes, immersion, or the potential for unexpected inhalation of or contact with hazardous levels of chemicals.

· 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 sheltering-in-place.