Antimicrobial coatings and sealants are liquid-applied, film-forming products, which contain a "bound" antimicrobial agent. They are designed to help prevent future growth of mold on previously contaminated surfaces that have been properly cleaned (ideally by a qualified Clean Trust Certified firm), particularly in environments where moisture control is difficult. [Note: Ad or content links featured on this page are not necessarily affiliated with The Clean Trust and should not be considered a recommendation or endorsement by The Clean Trust.]
Antimicrobial coatings and sealants should not be used in place of proper source removal of mold contamination, moisture control, or regular cleaning and maintenance. They can protect some materials from microbial growth. (Cole, Foarde, ACGIH Bioaerosols, 16.3.3).
Product Efficacy
Currently, there are no regulations regarding the nature, substance or minimum performance requirements of coatings and sealants formulated for mold. Antimicrobial coatings used in post-remediation applications demonstrate optimal performance results when tested in accordance with industry standards ASTM G-21 (‘0’ rating) and ASTM D-3273 (‘10’ rating).
Antimicrobial coatings and sealants should not create a vapor barrier that could lead to a buildup of moisture, and possibly contribute to a future microbial or structural problem. Products should demonstrate reasonable permeability as tested under ASTM D-1653. Antimicrobial coatings and sealants products should be water-based, low-odor, and contain low volatile organic compounds (VOCs).
Product Classes
- Mold-Resistant Coatings - Coatings and sealants that contain EPA-registered antimicrobials and are intended to inhibit mold growth on or in the coating film.
- Fungicidal Coatings - EPA-registered antimicrobial sealants designed to deliver antimicrobial activity on pre-cleaned surfaces, while also providing long-term inhibition of fungal growth on treated surfaces.
Use Limitations
Antimicrobial coatings and sealants are effective only when applied to surfaces that have been properly cleaned, and disinfected or sanitized when appropriate. A layer of dirt and debris accumulated on treated materials or surfaces can act as a physical barrier between the coating or sealant film and microorganisms, and eliminate product effectiveness. (Cole, Foarde, ACGIH Bioaerosols 16.3.3).
Mold-resistant coatings should not be used as sealants or encapsulants to contain or cover active, viable mold growth. Failure to properly clean and remove mold can permit continued growth beneath the coating, as the active ingredients in these products inhibit growth only on or in the coating film.
Fungicidal coatings should not be used as sealants or encapsulants to contain or cover active, viable mold growth. Fungicidal coatings are only effective as an antimicrobial after visible growth has been removed and the surface has been cleaned. Some jurisdictions might require users of fungicidal coatings to be licensed pesticide applicators.
Coatings and sealants should be applied only after post-remediation evaluation and verification. If antimicrobials, fungicidal coatings, mold-resistant coatings or sealants are used, and concerns exist that there could be future reoccurrence of mold, the use of non-pigmented (clear) coatings could permit future visual inspection of treated surfaces.
This information is quoted from the ANSI/The Clean Trust S520 Standard and Reference Guide for Professional Mold Remediation, 2d. Ed. ©, pages 120 &121, and is used by express permission of the copyright holder, The Clean Trust. No portion of the above excerpt can be duplicated without the written consent of The Clean Trust.
