Remediation
Biocides and antimicrobials: limits and legal rules
In plain English
R520 is clear that chemicals are not a substitute for removal. Killing mold does not remove what makes it a problem, because dead spores and fragments can still trigger allergic or toxic reactions. Indiscriminate spraying is discouraged. Professional judgment may still call for a biocide in particular cases, such as bacterial contamination from sewage covered by the S500 water standard.
The guide separates product classes. Sanitizers reduce microbes to safe levels. Disinfectants destroy fungi and bacteria on hard, non-porous surfaces but not necessarily their spores. Sterilizers aim to destroy all microbial life. A product may only be used against the organisms and on the surfaces its EPA registration covers, and only as the label directs. Off-label use violates the federal pesticide law (FIFRA). Fogging is acceptable only with products registered for that use.
Before applying an antimicrobial, R520 says to explain risks and benefits, share the safety data sheet, ask about health conditions, get written informed consent, and have people and pets leave. The remediator should not claim more than the label does. If used at all, these products go on after cleaning and verification, not before.
“Killing microorganisms with biocides does not typically destroy their antigenic or toxigenic properties.”
Key points
- Dead mold can still cause reactions; removal is the fix.
- Use products only for organisms and surfaces on their EPA label.
- Misapplying a registered pesticide violates FIFRA.
- Get written informed consent and clear the area of people and pets.
- Apply only after cleaning and post-remediation verification.
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 Reference Guide, IICRC S520 Standard and Reference Guide for Professional Mold Remediation — Reference Guide — Ch. 5, pp. 64–67. Best practice
- IICRC S520 Reference Guide, IICRC S520 Standard and Reference Guide for Professional Mold Remediation — Reference Guide — Ch. 11, p. 124. Best practice