Emergency and Technical Decontamination for Hazmat and Terrorism

Whether you are a member of a hazardous materials response team or a first responder, decontamination is one of the most important actions taken by emergency personnel during a hazmat or weapons of mass destruction (WMD) incident. Decon reduces the effects of hazardous materials and terrorist agents when response personnel and the public become contaminated. Decon also contains the hazardous materials or WMD agent to the “hot zone” and “warm zone” and prevents cross contamination.

According to the U.S. Occupational Health and Safety Administration (OSHA), “Decontamination means the removal of hazardous substances from employees and their equipment to the extent necessary to preclude the occurrence of foreseeable adverse health effects.” The National Fire Protection Association (NFPA) defines decontamination as the “physical or chemical process of reducing and preventing the spread of contaminates from persons and equipment used at a hazardous materials incident.”

Contamination, or the event that makes decon necessary in the first place, occurs in the hot zone. Everything and everyone entering the hot zone, including emergency response personnel, should be decontaminated to reduce the chances of creating additional contamination beyond the hot zone.

Three distinct zones are established during a hazmat incident: hot, warm, and cold. Anything or anyone who has been contaminated, including responders and victims and the product and container are located in the hot zone. The warm zone surrounds the hot zone and is where decon occurs. It is sometimes referred to as the contamination-reduction corridor. Outside of the hot and warm zones is everything else. No contamination should be present and it should be a reasonably safe area. This area is referred to as the cold zone.

There are two primary types of contamination, direct and cross. Direct contamination occurs in the hot zone. Cross contamination occurs when someone or something outside the hot zone was not properly decontaminated and comes in contact with another object or person, usually in the warm or cold zone. Therefore, the real mission of decontamination is to prevent cross contamination from occurring in the first place.

Equipment and the environment are secondary concerns. Entry-team personnel, even with proper personal protective equipment (PPE), should not come in contact with hazardous materials in the hot zone unless they absolutely must as part of mitigation efforts. This will help keep contamination to a minimum and make decon easier.

Besides the two types of contamination, there are also two primary types of decontamination, technical and emergency.

Technical Decontamination

Technical decontamination occurs when the hazmat team arrives on scene. It may involve decontamination of response personnel only or responders and victims.

When victims require decontamination, two or more decon lines will need to be established, one for personnel and the others for victims. Victims may be ambulatory or may need to be removed by properly protected responders through the decon line. Either specially trained decon personnel or hazmat team members will set up technical decontamination while the entry team is dressing out and preparing for entry.

Technical decontamination should be fully operational before the entry team begins operation in the hot zone. Some departments have developed trained decon units that respond when the hazmat team is dispatched on an alarm. They perform only decon functions. Decon personnel should not go on air supply until the entry team is preparing to exit the hot zone. This is done to ensure that decon team members have enough air supply to perform decontamination on entry personnel and themselves.