Remediation
Removing mold, cleaning up, and checking the work (S520)
In plain English
Workers should wear disposable or washable outer clothing that is thrown out or cleaned and taken off before leaving the work area, and the S520 says they "shall" meet every safety requirement the hazard assessment identifies, not just the PPE for mold. Leaving, coveralls are HEPA-vacuumed and rolled in on themselves, disposable outerwear is thrown away each time, clothing and hair are vacuumed, exposed skin is washed, respirators are cleaned and stored under the written respiratory program, and shoe soles are cleaned. Air scrubbers have their ducting removed and intake and exhaust sealed before they leave.
How a moldy material is handled depends on whether it can be returned to Condition 1, weighing the cost of replacing it against cleaning it. Remediators should match the cleaning method to the surface, limit the release of spores and fragments, put vacuum capture on any tool that makes dust, keep the floor clean with regular HEPA vacuuming, take out contaminated materials in pieces as large as practical and bag or wrap them in heavy plastic, get rid of sharps like nails and tack strip, clean remaining surfaces and the containment, clean any new materials installed before the job is done, and involve a structural engineer if structure is removed. Shared walls in apartments and condos bring the limits described in the disputes topic.
The goal after removal is that every surface in the work zone is free of visible mold and of visible dirt, dust and debris. The S520 recommends cleaning from top to bottom and cleaning the decontamination chamber at least daily.
Bagged waste is handled carefully, never dropped or thrown. If a bag breaks inside the house but outside containment, the area is closed off, PPE goes on, and the debris is HEPA-vacuumed and contained. From the house to the landfill there are generally no special rules for mold waste, but any laws on transporting and disposing of other materials apply.
The remediator checks its own work in a post-remediation evaluation (PRE): a thorough visual inspection, often a smell check, and sometimes tools such as laser particle counters, ATP meters and moisture meters. An area can be considered clean when the mold, unrestorable materials and debris are gone, surfaces are visibly free of dust (which can include wiping with a white or black cloth to see), there's no microbial odor, and remaining materials are dry; at that point a return to Condition 1 is probable. If not, the process is repeated. Without an independent check, air scrubbers keep running until the PRE says the job is done. A post-remediation verification (PRV) is the separate inspection and assessment by an independent, third-party IEP; see the verification topic.
Texas note: on a licensed Texas project, the remediator's own evaluation is not enough. A licensed Mold Assessment Consultant independent of the remediator must perform clearance, and walk-in containment stays up until it's passed.
Key points
- Outerwear off and disposed of or cleaned before leaving; vacuum, wash, clean shoes.
- Remove in large pieces, bag in heavy plastic, kill the dust at the tool.
- Done means: no visible mold, dust or debris, no odor, materials dry.
- Never drop or throw waste bags; contain any spill at once.
- PRE is the remediator's own check; PRV is by an independent IEP.
- In Texas, independent clearance is required on licensed jobs.
Official text
This topic is covered in our own words because the standard behind it is copyrighted; we cite it below rather than reproduce it.
Citations
- IICRC S520, ANSI/IICRC S520 Standard for Professional Mold Remediation — Secs. 9.3.6–9.3.8, suit up and entry, demolition and mold removal, cleaning, p. 49. Best practice
- IICRC S520, ANSI/IICRC S520 Standard for Professional Mold Remediation — Secs. 9.3.10–9.3.13, removal of equipment and personnel, disposal, post-remediation evaluation, post-remediation verification, p. 51. Best practice