• Decontamination is intended to protect employees, contain contaminants, and prevent the mixing of incompatible wastes.

Unfortunately, no matter how well a workplace is safeguarded against contamination, contaminants may still reach employees. Once a person is contaminated, exposure can occur and health effects may result. That means decontamination is critical to:

• Reducing employee exposure to hazardous substances, and
• Protecting employee health.

The Occupational Safety and Health Administration’s (OSHA) Hazardous Waste Operations and Emergency Response (HAZWOPER) Standard states that decontamination is the removal of hazardous substances from employees and their equipment to the extent necessary to preclude the occurrence of foreseeable adverse health effects.

Contaminants can be removed:

• Physically,
• Using chemicals to deactivate or neutralize the contaminants, or
• Using a combination of both physical and chemical removal methods.

One way of physically removing contaminants is by washing them off the surface, just as people wash their hands to prevent the spread of germs.

There are many different methods of decontamination that can be applied to employees, tools, equipment (including personal protective equipment, or PPE), instruments, samples, buildings, vehicles, roadways, soil, and even water supplies.

The process of decontamination is sometimes referred to as decon, decontaminating, or deconning. Its purpose is to:

• Protect employees as they remove contaminated PPE and chemical protective clothing (CPC),
• Prevent the mixing of incompatible wastes,
• Prevent others from being contaminated by minimizing the transfer of contaminants and contaminated equipment to clean areas of the site, and
• Protect the community by preventing the migration of contaminants from the site.

Decontamination procedures

Because decon is so critical to employee health, OSHA requires employers to have decon procedures in place. The agency requires all personnel to be appropriately decontaminated when leaving a contaminated area.

The decontamination process includes appropriately disposing of or decontaminating all contaminated clothing and equipment before leaving a contaminated area. The outside of sample containers too should be decontaminated.

Decontaminating PPE is an important part of maintaining its usefulness and effectiveness, along with cleaning, laundering, maintaining, and replacing it as needed.

At a hazardous waste cleanup site, the decon procedures will be part of the site-specific safety and health plan. For emergency response operations, the decon procedures will be part of the emergency response plan (ERP).

Decontamination procedures establish a standard way of performing decon activities. Employers must develop procedures that address:

• The number and placement of decon stations,
• The necessary decon equipment and methods,
• Procedures to prevent contamination of clean areas,
• Procedures to minimize contamination during the removal of PPE and CPC, and
• How to handle clothing and equipment that may not be able to be completely decontaminated.

Employees should read through all decontamination procedures before entering any areas with the potential for exposure to hazardous substances.

It’s also a good idea to run practice drills of decon procedures in non-contaminated areas, especially for the decon of personnel dressed out in their PPE and CPC. These drills may be slow going at first, but with practice, they can help employees perform actual decon activities quickly and efficiently, which may be necessary when an entry worker in a self-contained breathing apparatus (SCBA) is running out of air.

According to the HAZWOPER Standard, decontamination procedures must be monitored to determine their effectiveness. If any deficiencies are discovered in the procedures, steps must be taken to correct them.