Mold
Mold grows wherever there is moisture: after floods and leaks, and in crawl spaces, attics and wall cavities. Renovation, demolition and cleanup workers can breathe in large amounts of mold spores when they disturb moldy materials.
- Construction
- Remediation
Photo: worker removing moldy drywall inside plastic containment
Health effects
- Allergic reactions: sneezing, runny nose, red eyes, skin rash
- Asthma attacks, and new asthma in some workers
- Irritation of the eyes, nose, throat and lungs
- Rarely, a serious lung reaction called hypersensitivity pneumonitis, with fever and shortness of breath
- Infections in people with weakened immune systems
Tell your doctor about mold exposure if you have breathing problems, and tell your supervisor if you have asthma or a weakened immune system before working on a mold job.
Size of the job
| Area of mold | General approach |
|---|---|
| Less than about 10 square feet | Usually can be handled by trained workers with an N95 respirator, gloves and goggles |
| Larger areas, HVAC systems, or heavy contamination | Professional remediation methods: containment, negative air with HEPA filtration, and a higher level of respirator |
These are EPA guidelines, not federal rules. Some states license mold assessors and remediators; check your state.
Safe cleanup
- Fix the water problem first, or the mold will come back.
- Wear an N95 respirator (or better), gloves and goggles without vents. A respirator requires fit testing under your employer’s program. See Respirators.
- Set up plastic sheeting to contain the area, and keep spores out of HVAC returns.
- Remove and bag porous materials that are moldy: drywall, insulation, carpet, ceiling tiles.
- Clean hard surfaces with detergent and water, then dry them completely within 24 to 48 hours.
- Mist materials lightly to keep spores down; clean up with a HEPA vacuum, not dry sweeping.
- Wear disposable coveralls on bigger jobs, and remove them before leaving the work area.
- Don’t paint or caulk over mold.
- Don’t mix bleach with ammonia or other cleaners; it makes toxic gas.
- Don’t run the building’s HVAC system if it may be contaminated.
- Don’t assume older materials are only moldy. Drywall compound, flooring and insulation may also contain asbestos or lead paint. See Asbestos.
Before starting a mold job
- Water source found and fixed
- Size of the moldy area estimated
- Asbestos and lead checked in older buildings
- Respirator fit-tested; gloves, goggles and coveralls on hand
- Containment and HEPA equipment ready if needed
- Electrical hazards checked after flooding
Standards & references
- EPA: Mold
- OSHA: Mold
- See also: Cleaning Up After a Flood · Mold at Home
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