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Module 2

Safety

 

Learning Objectives

After completing this Module, you will be able to:  

Hazardous materials incidents differ from other emergencies in many ways. First responders must be aware of the complexities of chemical, biological, radiological and nuclear hazardous materials incidents and the impact and potential harm they cause. Further, an awareness of what materials are toxic, and how they are dispersed will assist first responders in minimizing risks. First responders must be aware that self-protection is the first priority and it must be maintained before they can protect fellow responders and the public.

1. Complexity (Types of Hazards)

Hazardous materials incidents can be much more complex than other types of emergencies. Responses to the incidents are more complex because they:

1.1 Impact

Hazardous materials incidents can have a tremendous impact on victims, responders, the community and the surrounding environment. Most will not go away without mitigation and rescue may be difficult, if not impossible.

The risks that hazardous materials incidents present to responders can include:

1.2 Potential Harm

There are numerous ways hazardous materials incidents can be harmful to responders, including:

The acronym TRACEM is an easy way to remember them. Each has different harmful effects.

Thermal.

Thermal harm is the result of exposure to the extremes of heat or cold. Heat travels by one of four methods: conduction, convection, radiation, and direct flame contact.

Radiological.

Radiation (in this context) refers to nuclear radiation, not a method of heat transfer. There are three types of nuclear radiation:

Alpha, is the least penetrating and is not considered dangerous unless alpha contaminated particles enter the body through mechanisms such as ingestion.

Beta, is more penetrating and can cause skin damage and   22 harm internal organs if ingested. The use of PPE including SCBA will greatly enhance emergency responder’s safety when dealing with alpha or beta radiation.

Gamma has great penetrating power. Gamma rays are high-energy ionizing radiation that cause skin burns, severely injures internal organs and has long-term effects. Medical radioactive isotopes may be generally dispersed through the explosion of a “dirty bomb” causing extensive long-term health damage including radiation sickness.

Asphyxiation.

Asphyxiants interfere with oxygen flow either by diluting the concentration of oxygen concentration or interrupting the flow in the blood or to the tissues. The asphyxiants prevent proper oxygen distribution and the cells of the body ultimately die. Examples of asphyxiants are hydrogen cyanide (AC), cyanogens chloride (CR) phosgene, carbon monoxide (CO), anilene and hydrogen sulfide.

Chemical.

Chemicals can cause harm either through toxicity or corrosion. Symptoms are obvious in minutes to a few hours after exposure.

Toxic agents cause damage depending on the length of time of the exposure and the concentration of the chemical. Nerve agents are toxic chemical materials. They can be in either liquid or gas form and are inhaled causing immediate respiratory distress. They will result in mass fatalities showing no other external signs of trauma.

Corrosive materials cause a blister or burn after direct contact. They can be liquid or solid and cause visible or irreversible alterations in skin tissue at the site of contact. Sulfuric acid is an example of a corrosive material.

Etiological/biological.

This type of harm involves exposure to a living microorganism, virus or it’s toxin which may cause disease and death in humans. They are usually odourless and colourless. The onset of symptoms could take days or weeks. In some instances symptom onset can be very rapid (as short as 4 to 6 hours).

Large areas/populations are usually affected due to the movement or travel of infected persons prior to the outbreak of symptoms.

The most frequent route of exposure is through inhalation or ingestion, however absorption through the skin and injection are possible. Four common types of biological agents are: bacteria, viruses, rickettsia and toxins.

Examples:

Indicators of an etiological/ biological event may include: unusual numbers of sick or dying animals or people; dissemination of unscheduled or unusual sprays, outdoors and/or at night; abandoned spray devices with no distinct odour.

Mechanical

The most common type of harm comes from contact with mechanical or physical hazards. This could be from an explosive device in the form of shrapnel or nails. Other examples of mechanical harm include routine slip, trip and fall hazards at an emergency scene.

Clandestine drug/chemical labs can cause physical and chemical harm to responders due to intentionally placed hazards that include disguised holes cut in floors, hidden explosive devices, discarded needles, toxic or flammable vapours, electrical or chemical hazards and other lethal dangers. The sole purpose of these hazards is to injure or kill persons entering the lab.

Psychological

The fear of exposure or long-term effects can create a paranoia that disrupts normal activities resulting in major economic, financial, social and health care issues.

1.3 Exposure

Short or long term exposure to hazardous materials incidents can have acute or chronic health effects. However, the threat of exposure during an accidental release can differ from that   24 of an intentional release (terrorism). An intentional release of nuclear, biological or chemical materials can tremendously increase the potential for responder exposure.

Implementing the Protective Measures of Time Distance and Shielding is a major self-protective strategy.

Incident Characteristics TRACEM TDS Measures
Biological Community public health emergencies such as a cholera or anthrax bacterial outbreak or Ebola viral contamination.

Focused response is the discovery of a biological agent or its release.

 Etiological Time: Minimum contact time. Some agents can be fatal very quickly and in small amounts. Distance: Maximum when unprotected, including distance from those contaminated or exposed casualties. Shielding: Maximum appropriate to the agent, including masks and splash protection.
Nuclear Potential for radiological dispersal device. Primarily radiological. May include thermal, chemical or mechanical. Time: Minimum to reduce exposure. Distance: Maximum from hazard. Shielding: PPE, including hoods, respiratory protection and lead walls.
Incendiary Multiple fires with unusual volume for structure. Evidence of accelerants or arson. Thermal but could include asphyxiative, chemical and mechanical. Time: minimum exposure.

Distance: Maximum without PPE.

Shielding: Appropriate PPE.
Chemical May include hazardous materials absorbed, inhaled, ingested or injected. Could include ammonia, chlorine, gasoline. Primarily chemical but may include thermal, asphyxiative and mechanical. Time: Minimum exposure time and contact with product.

Distance: Maximum from actual chemical remaining; uphill and upwind; away form contaminated areas and casualties unless wearing PPE.

Shielding: Maximum appropriate to the agent.
Explosive Multiple hazards are possible with very unique situations. Primarily mechanical, but may include thermal, chemical, biological or radiological. Time: Shortest interval, explosions take place in hundredths of a second.

Distance: Maximum. Consult 2000 Emergency Response Guidebook (2000 ERG)

Shielding: Maximum. Avoid line of sight and be aware of secondary devices and structural collapse.

2. Threats Posed by Hazardous Materials

Hazardous materials can present threats to health, property and the environment in a variety of ways. This is because hazardous materials can come in the form of solids, liquids or gases.

First responders must be aware that the routes of entry for human exposure include:

2.1 Toxicity of Hazardous Materials

Hazardous materials are considered to be toxic (poisonous) to   26 people and other living organisms. The degree and type of toxicity varies for individual substances.

Categories of toxicity symptoms include:

2.2 Dispersion Pathways

The dispersion pathways of these three states of hazardous materials include:

The type of area (terrain, climatic conditions) where a substance is released may affect the dispersion of that material causing different reactions. For example, once the hazardous material is released, the toxicity of the substance may change through dilution or degradation. Other materials remain toxic because they resist degradation. In such cases, they will require specialized clean up procedures and equipment. Further, they will find pathways to harm humans (i.e. water, food chain, etc) and the environment. Continued exposure may induce further negative toxicological effects on humans and the environment.

Contact with the atmosphere or other materials may produce violent and/or toxic results.

2.3 Potential Ignition Sources

First responders must be aware of the additional risk of ignition at a hazardous materials incident. They must know that where a flammable/explosive atmosphere exists, some   27 potential ignition sources that can cause fire and/or explosions include:

2.4 Explosive Incidents.

Canadian Transport Emergency Centre (CANUTEC) defines explosives as products or substances that:

“are capable by self-sustaining chemical reaction, of producing gas at such temperature, pressure and speed as to damage the surroundings, or are manufactured for the purpose of producing a explosive or pyrotechnic effect.”

It is estimated that 70% of all terrorist attacks worldwide involve explosives.

Other potential hazards at an incident can include:

3. Think “Safety First”

First responders must always think “safety first” and protect themselves, so they can protect fellow responders and the public.

3.1 Protective Clothing

In order to mitigate possible exposure to hazardous materials, first responders who are trained to respond to these incidents must wear appropriate protection. The use of proper respiratory protective equipment and clothing is paramount. Street clothes and work uniforms will not provide protection from the hazards of harmful substances. Structural protective firefighter clothing does not provide chemical protection, and can, in fact absorb dangerous vapours. Specialized chemical protective clothing is needed to protect an appropriately trained first responder who is working in close proximity to a hazardous material spill or release. First responders exposed to hazardous materials must wear the appropriate respiratory protection, and be properly fitted and trained in the use of the respiratory equipment.
Protective clothing is divided into four categories, which are used for specific circumstances. These are:

  1. Level A – fully encapsulating vapour protective chemical suits with SCBA (self-contained breathing apparatus)
  2. Level B – partially encapsulating suits with SCBA
  3. Level C – partially encapsulating suits with an air purifying respirator
  4. Level D – structural protective firefighter clothing or street clothes

3.2 Emergency Medical Care

During a hazardous materials incident, awareness level first responders may encounter contaminated or potentially contaminated non-ambulatory victims. The first responder must remember to think “safety first” and not rush to aid the victim until steps are taken to render such action safe. As an Emergency Medical Services (EMS) provider, the first responder may need to wait in a safe area, identified as the “Cold Zone", to receive decontaminated patients. Victims should be screened as soon as possible to determine vital signs, extent of injuries, and exposure details.

Important factors to remember when first responders approach a potential hazardous materials incident are:

3.3 Decontamination/Isolation

First responders may encounter contaminated victims at hazardous materials incidents, and could potentially become contaminated themselves. In addition, equipment used in the response could also come in contact with contaminants. Individuals and equipment contaminated during an incident must be isolated from other people and property to minimize further contamination spread, and then be properly decontaminated.

Contaminated victims with no life threatening injuries should be decontaminated by properly trained personnel. Appropriate preventative action must be taken to minimize contamination of transport vehicles and hospital emergency receiving areas. Awareness level first responders are advised not to perform decontamination of personnel or equipment. However, a description of decontamination activities is provided to allow first responders to become familiar with expected procedures.

Decontamination planning should include:

  1. site layout
  2. decontamination methods to be used
  3. number of personnel needed
  4. level of PPE and equipment to be processed
  5. disposal methods
  6. run-off control
  7. emergency medical requirements
  8. methods for collecting and disposing of contaminated clothing and equipment

The steps you might go through for contamination reduction/management are:

washing/rinsing to remove gross contamination

Emergency response personnel who have been contaminated but are not in need of immediate medical attention must report to the established decontamination area.
Contaminated equipment, clothing, decontamination solutions including rinse water and other materials must always be left in the decontamination area until the items can be properly decontaminated or disposed of. In such cases, the first responder should notify designated decontamination personnel of the particular equipment that potentially has been contaminated.

Decontamination personnel will:

Summary

First responders trained to the awareness level must ensure that personal safety is maintained. They must be aware of the complexity, impact, and potential harm that the various types of hazardous materials present, and how to avoid exposure. The wisest course of action is to delay entry and await the arrival of appropriately trained and equipped personnel. First responders must have an awareness of the threats to health, property and the environment presented by hazardous materials. Specific steps to be taken include isolation of the scene, notification of appropriate personnel and recognition of key indicators of a potential terrorist incident.  

Learning Check- Module 2

True or False. Circle T or F

1. T F One reason why hazardous materials incidents responses are more complex than other emergencies is because they require specialized protective equipment for the first responder.
       
2. T F Given enough time, the impacts of most hazardous materials will go away without mitigation.
       
3. T F Alpha radiation is the most penetrating kind.
       
4. T F Chemical exposures can present a risk to first responders at hazardous materials incidents.
       
5. T F A safe area, where first responders can receive decontaminated patients is called a “Cold Zone”.
       

Multiple Choice. Circle your answer.

  1. Additional hazards that can compound a hazardous materials incident include:
     
    1. open flames
    2. b. traffic
    3. c. booby traps
    4. d. all of the above
       
  2. Which is not a usual route of entry for human exposure to a hazardous material:
     
    1. absorption
    2. inhalation
    3. infusion
    4. ingestion
       
  3. Protective clothing that is designated as Level A. is:
     
    1. structurally protective firefighter clothing
    2. fully encapsulating vapour protective chemical suits with SCBA
    3. partially encapsulating suits with SCBA
    4. turn out gear
       
  4. A first responder trained to the awareness level, who becomes aware that equipment has potentially become contaminated should:
     
    1. immediately perform decontamination procedures
    2. wash the equipment to remove gross contamination
    3. notify designated decontamination personnel
    4. ensure the proper containment or disposal of the equipment
       
  5. The appropriate response for a first responder trained to the awareness level, at a potential terrorist incident is:
    1. isolate the scene
    2. identify potential risks
    3. notify appropriate personnel
    4. all of the above