You are here: Home > Public Incident

Public Incident

Preparing to Respond

  • Causes of Public Incidents
    • There are many ways in which a chemical emergency may occur. The release itself may be caused by:
      • a leak or spill from a container,
      • a chemical fire
      • a natural disaster, such as the release of gases from volcanoes
      • a transportation accident
      • an act of terrorism
      • human error

  • What to Expect
    • In addition to the toxic effects of a chemical incident, chemical release into a community often causes considerable public anxiety. Responders should expect and be prepared to handle victims coping with:
      • Chemical incidents, by the very nature of the way many of them occur, will affect people in a number of ways.
      • Effects of explosion. People may be subjected to blast injuries, mechanical trauma, the effects from building and structural damage and collapse, and from loss of housing and shelter.
      • Effects of fire. People may be burnt or exposed to smoke and heat inhalation, or suffer from the longer term sequelae.
      • Effects of natural disasters. People may be subjected to the suffocating effects of ash, to mudslides and loss of housing and amenities.
      • These physical effects are often seen in major trauma incidents; and other emergency planning systems have usually already been developed to cope with these.

      However, it should not be forgotten that during a chemical incident these effects may in fact present more of a health problem than the chemical itself.
      • Socio/psychological effects.
      • Effects of the toxic nature of chemicals.

      During an incident, lack of information because of the wish for secrecy, or differing professional opinions may raise public anxiety levels. Occasionally, public anxiety may lead to the mimicking of symptoms. (See Risk Communication)

    • Large Geographic Scale. When a disaster scene covers a large geographic area, collecting and managing hazard information becomes problematic because of the difficulty of getting an overview of the scene.

    • Multiple, Highly Varied Hazards. Because the numerous hazards at the site of a major disaster are so diverse, they will inevitably go well beyond the experience of single response agencies. This makes it very difficult for individual organizations to characterize threats.

    • Potential for Large Numbers of People Affected, Injured, or Killed. Efforts of local organizations to gather hazard data can be hindered by operational demands, such as the need to devote responder resources to aiding substantial numbers of victims.

    • Prolonged Duration. Because disaster responses extend over long periods, logistics efforts must be put in place to sustain operations over days, weeks, or even months.

    • Wide Range of Needed Response Capabilities. The involvement of many independent response organizations in responding to a major disaster can complicate efforts to amass accurate hazard data. If many agencies independently carry out hazard monitoring efforts, problems in coordinating either assessment methods or the guidelines used to interpret results can produce inconsistencies in the data.

    • Damage to Infrastructures. Difficulties in collecting needed information are exacerbated by damage to or disruption of critical infrastructures. In many disaster situations, communications systems are damaged or overloaded with traffic, preventing responders from collecting and sharing information.

    • Direct Effects on Responder Organizations. Disasters can damage response organization assets needed to gather information after an incident occurs.

  • Planning and Multi-Agency Coordination of Responsibilities and Resources
    1. Define Hazard Types and Information Needs. Because not all hazards can be measured simultaneously, choices must be made about what hazards are examined first at particular events. By defining how rapidly hazard information will be needed, local planners can determine which assessment capabilities will be needed immediately and therefore must be provided locally. Other assessment capabilities, perhaps less critical or not needed immediately, could be provided by reinforcing organizations coming from beyond the local area. Responders identified the immediate need to monitor the environment for chemical agents, biological agents, radiation, flammable gases, and oxygen deficiency as key. Such a list provides a clear strategy for what hazards should be examined as assessment resources arrive at a scene.

    2. Develop Local Hazard Monitoring Capabilities. When a major crisis hits, safety managers will need certain hazard data immediately. Capabilities must be in place at the local level to gather that information. Data on facilities and locations that could present safety and health risks for responders is one key example of this kind of information. Such data can be acquired through facility inspections, regulatory filings, or other data collection. Because such information is only useful if it is immediately available and up to date, the importance of keeping this type of information current and readily accessible to responders cannot be overemphasized.

    3. Arrange for Access to Needed Hazard Assessment Resources in Other Organizations. The diversity of hazards that can exist after a major disaster means that individual response organizations must often rely on external organizations to provide supplemental hazard assessment capabilities and expertise. For example, external organizations possess technology and expertise to measure hazards such as airborne pollutants, heavy metals, asbestos, particulates, and others. In addition, external organizations can also provide access to technical assets that local response organizations could never support on their own. Agreements must also be in place to ensure that information produced by these varied sources can be effectively shared and used among response organizations.

    4. Plan for Influx of Convergent Volunteers and Supplies. Convergent volunteers, who are often not connected with any defined organization, present significant challenges to management systems. Similarly, uncoordinated delivery of supplies or equipment to the disaster scene can choke responder logistics systems. When incoming supplies are not systematically catalogued, responders may not be able to use them to support their efforts.

top of page

Guidelines for Incident Command

  1. Establish Incident Command System (FEMA).

  2. Approach site with caution.
    Position personnel, vehicles, and command post at a safe distance upwind and uphill of the site, if possible.

  3. Ensure safety of responders.
    • Identify all hazards (danger of fire, explosion, toxic fumes, electrical hazards, structural collapse, etc.).
    • Obtain information concerning the chemicals from placards, labels, shipping documents, and other immediately available sources.
    • Consult Emergency Response Guidebook (PDF - 4.7 MB) (2016 Emergency Response Guidebook: A Guidebook for First Responders During the Initial Phase of a Dangerous Goods/Hazardous Materials Incident, Department of Transportation, 2016). (Online version at Transport Canada) (Mobile apps)
    • Consult NIOSH Pocket Guide to Chemical Hazards for symptoms, measurement methods, and PPE recommendations.
    • Keep upwind of smoke, fumes, etc.
    • Follow usual protocols for respiratory protection, use of protective clothing , and turnout gear. (See Personal Protective Equipment)
    • Monitor changing conditions that could create hazardous situations.

  4. Locate victims and facilitate extrication, emergency care, and transportation of the injured, following EMS guidelines. Do not delay rescue or transport of a seriously injured, contaminated patient.

  5. Communications: Notify hospital of possible contamination/exposure of victim.

  6. Establish a control zone.
    • Reroute traffic.
    • Mark controlled area by use of ropes or tapes.
    • Limit entry to rescue personnel only.
    • Order evacuation or sheltering as needed.

  7. Prevent/fight fires as if toxic chemicals are involved.

  8. Ensure contamination control.
    • Do not allow eating, drinking, smoking, or other activities within contaminated areas that might lead to intake of chemical.
    • Avoid direct contact with materials where possible. Utilize protective clothing and anything available for remote handling (shovels, branches, ropes, etc.).
    • Limit time near chemicals to the minimum necessary. Rotate staff as necessary.
    • Evacuate personnel from the immediate downwind area. Detain personnel who were in the accident area until they can be decontaminated (See Decontamination).
    • Wrap, label, and isolate all clothing, tools, etc., used in the controlled area and retain them until they can be decontaminated.
    • Determine if measures are needed to contain all accident debris in the control zone until cleanup is achieved. Prevent unnecessary handling of incident debris.

  9. Documentation
    • Record the names and addresses of all persons involved (including those who insist on leaving the area), rescuers, those removed for medical attention, and ambulance personnel.
    • Make detailed records of the incident.

  10. Remain calm.

top of page


  1. Emergency Preparedness and Response: Chemical Emergencies (HHS/CDC)
  2. Emergency Preparedness and Response: Toxicology Profiles for Chemical Agents (HHS/CDC)
  3. O'Leary M. (2004) The First 72 Hours: A Community Approach to Disaster Preparedness. Lincoln (Nebraska), iUniverse Press. Available online for a fee.
  4. Protecting Emergency Responders, Volume 3: Safety Management in Disaster and Terrorism Response. NIOSH Publication No. 2004-144. (HHS/CDC/NIOSH, 2004)
  5. Emergency Response Guidebook (2016 Emergency Response Guidebook: A Guidebook for First Responders During the Initial Phase of a Dangerous Goods/Hazardous Materials Incident, DOT, 2016)
  6. NIOSH Pocket Guide to Chemical Hazards (HHS/CDC/NIOSH)
  7. Health Library for Disasters. Public Health and Chemical Incidents - Guidance for National and Regional Policy Makers in the Public/Environmental Health Rules (PAHO, WHO, 1999)
  8. Unaffiliated Volunteers in Response and Recovery (PDF - 962 KB) (Volunteer Florida)

PDF documents can be viewed with the free Adobe® Reader™