HAZMAT Response Discussion and Questions: Decontamination
What Is Decontamination?
Decontamination is the physical or chemical process of reducing and preventing the spread of hazardous materials by persons and equipment. Decontamination makes personnel, equipment, and supplies safe by removing or eliminating hazardous materials. Proper decontamination is essential at every hazardous materials incident to ensure the safety of personnel and property.
Contamination is the process of transferring a hazardous material from its source to people, animals, the environment, or equipment, which may act as carriers of the contaminant. Secondary contamination (also known as cross contamination) occurs when a contaminated person or object comes into direct contact with another person or object. Secondary contamination may occur in several ways:
• A contaminated victim comes into physical contact with a fire fighter.
• A bystander or fire fighter comes into contact with a contaminated object from the hot zone.
• A decontaminated fire fighter re-enters the decontamination area and comes into contact with a contaminated fire fighter or object.
Because secondary contamination can occur in so many ways, control zones should be established, clearly marked, and enforced at hazardous materials incidents.
The more people who are exposed, either directly or indirectly, to the contaminant, the larger the decontamination problem. A rapid, focused decontamination operation depends on an understanding of the contaminant and its chemical properties.
Types of Decontamination
Decontamination makes personnel, equipment, and supplies safe by removing or eliminating the hazardous materials. Government and industrial agencies are responsible for decontaminating the environment, while specialists decontaminate equipment such as collected tools. Fire fighters are responsible for establishing a decontamination corridor for the initial emergency response crews and victims. The decontamination corridor is a controlled area, usually within the warm zone, where decontamination procedures take place. Everyone who leaves the hot zone is required to pass through the decontamination corridor as they exit.
The major categories of decontamination are emergency decontamination, gross decontamination, formal decontamination, and fine decontamination. Each category provides a different level of decontamination.
Emergency decontamination is used in potentially life threatening situations to rapidly remove most of the contaminants from an individual, regardless of a formal decontamination corridor. A more formal and detailed decontamination process may follow later. Emergency decontamination usually involves removing contaminated clothing and dousing the victim with quantities of water. If a decontamination corridor has not yet been established, isolate the exposed victims in a contained area and establish an emergency decontamination area. Do not allow the water runoff to flow into drains, streams, or ponds; try to divert it into an area where it can be treated and/or disposed of later. Do not delay decontamination; human life always comes first.
Rapid Mass Decontamination
Rapid mass decontamination is used in incidents involving unknown agents and large groups of people. It takes place in the field and is a way of quickly performing gross decontamination on a large number of victims who have escaped from a hazardous materials incident. Because water is a generally effective solvent, washing off as much of the contaminant as possible with a massive water spray is the best and quickest way to decontaminate a large group of people. Rapid mass decontamination requires a minimum of two fire apparatus placed side by side. Place fire nozzles on the side discharge outlets and use a spray pattern to douse the victims. An aerial ladder device can provide a complete overhead spray.
In rapid mass decontamination, the primary concern is to remove a hazardous material from a large number of victims. It can take place on any street, parking lot, or area where fire apparatus can be deployed with a continuous, uncontaminated water supply. Environmental concerns are secondary; there is usually not time to build structures to contain runoff.
These victims will need further decontamination and medical monitoring after they have been sprayed. When more emergency responders arrive, they can establish a decontamination corridor to clean and thoroughly decontaminate the victims before transporting them to a medical facility.
When a contaminated person comes into direct contact with another person or object there is:
A. secondary contamination.
This method of decontamination is used during incidents involving unknown agents and large groups of people.
A. Emergency decontamination
B. Group decontamination
C. Gross decontamination
D. Rapid mass decontamination
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