5.4 Decontamination—General Information
All personnel, clothing, equipment, and samples leaving a contaminated area must be decontaminated to remove any harmful chemicals or biological agents that may have adhered to them. Decontamination procedures must be tailored to site-specific hazards and will vary in complexity, depending on the agent(s), the extent of contamination, the items being decontaminated, and prevailing environmental conditions (e.g., wind). The chemical and physical compatibility of the decontamination solutions or other decontamination materials must be evaluated before they are used. Any decontamination method that permeates, degrades, damages, or otherwise impairs the safe functioning of the PPE must not be used. Some chemical decontamination agents may be hazardous if they are inhaled or are in prolonged contact with skin, eyes, and/or mucous membranes. Care must be taken to protect personnel from such materials.
In the case of a life-threatening event, decontamination may be delayed until the victim is stabilized. But decontamination must always be performed first, when practical, if it can be done without interfering with essential life-saving techniques or first aid, or if a worker has been contaminated with an extremely toxic or corrosive substance that could cause severe injury or loss of life. During an emergency, provisions must be made for protecting responding medical personnel. In all cases, fluids used for decontamination must be captured for appropriate treatment and disposal.
The Guide for the Selection of Chemical and Biological Decontamination Equipment for Emergency First Responders (NIJ Guide 103–00, published by the National Institute of Justice) provides information about the selection and use of chemical and/or biological decontamination equipment for various applications. Emergency responders should contact EPA’s Consequence Management Advisory Team if they require additional assistance in determining the appropriate decontamination procedures for agents (e.g., anthrax).
Decontamination procedures for chemical agents depend on the nature of the agent. Decontamination procedures must be tailored to the specific site hazards and will vary in complexity, depending on the agent(s), the extent of contamination, the items being decontaminated, and prevailing environmental conditions (e.g., wind). Section 5.0 of the manual’s PPE Program chapter provides procedures for decontamination of PPE.
The NRT Quick Reference Guides for chemical warfare agents contain recommendations for decontaminating equipment and personnel. In general, the NRT recommends decontaminating outer PPE with a dilute hypochlorite solution (0.5 percent) or one part household bleach to 10 parts water. For decontaminating bare skin, soap and clean or potable water must be used instead of dilute bleach. Other information about decontamination can be found on EPA’s Homeland Security Research website.
Decontamination of protective clothing and equipment used during a biological incident response must begin before gear is removed, to ensure the removal or neutralization of particles that have settled on the outside of protective equipment. Decontamination sequences used for hazardous material incidents must be followed for biological agent incidents as well.
Equipment can be decontaminated using soap and clean or potable water. A 0.5 percent hypochlorite solution can be used if gear has any visible contamination or if otherwise necessary. However, bleach damages some types of PPE. After taking off gear, emergency responders must shower using copious quantities of soap and water. Care must be taken to protect personnel from bleach or other hazardous agents used to decontaminate equipment. Text Box 5 presents various methods used to decontaminate items used in a biological incident response.
The NRT Quick Reference Guides for biological warfare agents contain recommendations for decontamination of equipment and personnel. Also, Appendix D contains a list of references on emergency response and remediation techniques related to aerosolized anthrax.
Text Box 5
Decontamination of Emergency Responders and Equipment
Decontamination removes and/or neutralizes (inactivates) biological agents on contaminated surfaces and plays an important role in controlling the spread of the agent. Decontamination includes the disinfection or sterilization of infected articles (e.g., clothing and equipment) to make them suitable for reuse. Items can be decontaminated by mechanical, chemical, and physical methods depending on the agent and site-specific conditions:
Mechanical decontamination involves measures that remove (but not necessarily neutralize) agents, such as, rinsing or washing with soap and water or using a brush to remove agents. Physical removal by HEPA vacuuming or brushing inside a negative pressure enclosure is a sound practice for initial decontamination.
Chemical decontamination inactivates a biological agent by the use of disinfectants. Washing with a bleach solution is one example. Careful washing with soap and water removes most biological contamination from a surface, including skin and hair, and is often sufficient to avert contact infection. Rooms should be decontaminated with disinfectant gases or liquids in aerosol form (e.g., chlorine dioxide) to ensure complete decontamination. These methods are not appropriate for decontaminating people.
Physical decontamination renders most biological agents harmless through physical means, such as heat (autoclave), sunlight, or ionizing radiation. These methods are only suitable for decontaminating durable items. However, sunlight cannot destroy Bacillus anthracis spores.