HAZWOPER guide · 2 min read · Updated 2026-11-03
HAZWOPER Decontamination Procedures: Decon Line Setup and Steps
Decontamination ("decon") removes or neutralizes contaminants that have built up on people and equipment, so hazards don't leave the work area. OSHA 29 CFR 1910.120(k) requires a written decontamination procedure, developed and communicated to employees before anyone enters a site where they may be exposed.
What OSHA requires
- All employees leaving a contaminated area must be decontaminated, and all contaminated clothing and equipment leaving must be decontaminated or disposed of
- Decon must happen in areas that minimize exposure of uncontaminated employees or equipment
- The site safety and health officer monitors the procedure and revises it if it isn't working
- Equipment and solvents used for decon must themselves be decontaminated or disposed of properly
- Protective clothing that can't be decontaminated is disposed of; contaminated clothing is never taken home
- Showers and change rooms are provided where decon procedures call for them
Decon methods
- Physical removal: brushing, scraping, rinsing, wiping, vacuuming with HEPA filtration
- Dilution: water or detergent wash and rinse
- Chemical: neutralization, solidification or a solvent matched to the contaminant. Check compatibility first so the decon solution doesn't create a new hazard
- Disposal: disposable PPE removed and bagged as waste
Where decon happens
Decon takes place in the contamination reduction zone (CRZ), the transition between the exclusion zone and the clean support zone. Inside it, the contamination reduction corridor holds the decon line, laid out from dirtiest to cleanest with the access control point at the clean end. See site control and work zones.
A typical decon line
- Segregated equipment drop: leave tools, sampling gear and instruments on plastic sheeting or in containers
- Boot cover and outer glove wash
- Boot cover and outer glove rinse
- Tape removal at wrists and ankles
- Boot cover removal
- Outer glove removal
- Suit and safety boot wash
- Suit and boot rinse
- Tank change or redress, if returning to the exclusion zone
- Safety boot removal
- Splash suit removal
- Inner glove wash and rinse
- Facepiece removal
- Inner glove removal
- Inner clothing removal, field wash and redress
The number of stations depends on the PPE level and contaminant. Level A and B lines are longer; Level C and D lines may only need a few steps.
Checking decon worked
Methods include visual inspection (sometimes under UV light for fluorescent contaminants), wipe sampling of PPE or skin, and testing the final rinse solution. Results feed back into the procedure.
Emergency decon
If a worker is injured or seriously exposed, life-saving care comes first. Gross decon such as removing outer clothing and flushing with water can be done quickly; full decon may be skipped if it would delay critical medical treatment. Wrap the victim to limit spread and tell medical staff what the contaminant is.
Frequently asked questions
Where is the decontamination line located?
In the contamination reduction zone (warm zone), between the exclusion zone and the support zone, arranged from most contaminated to least contaminated.
Does OSHA require a written decon procedure?
Yes. 1910.120(k)(1) requires a decontamination procedure to be developed, communicated to employees and implemented before anyone enters a site where they may be exposed.
Should decon be done before emergency medical treatment?
Not if it would delay life-saving care. Perform gross decon if it can be done quickly, protect medical responders and tell them what the contaminant is.
This guide summarizes federal OSHA, Cal/OSHA and EPA rules for training purposes. It is not legal advice. Always check the current regulation text and your site safety and health plan.