Do HVAC antimicrobials really work?

By Robert Preuss

WASHINGTON — Government regulators will take a hard look at disinfectants/sanitizers used in HVAC systems.

Review will focus on two main issues:

Risk to building occupants

"We may need to call in data to allow us to perform a full risk assessment," Debra Edwards, associate director, Antimicrobials Division, Office of Pesticide Programs, US Environmental Protection Agency, told CM e-News DailyCMDistributionOnline Wednesday.

Concerns include the potential for adverse health effects from inhalation of chemicals applied to HVAC systems.

Effectiveness

"Unless these products are applied directly to surfaces throughout HVAC systems, which would likely require that the systems be dismantled, we have no confidence that they'll be effective," Edwards said.

The EPA will ask suppliers to provide efficacy data to support product registration for products that claim to sanitize or disinfect ductwork, Edwards said.

While there are a very limited number of products registered for use in HVAC systems, there is also a concern that disinfectants registered for use on hard or porous surfaces are also being used in HVAC systems where use may be inappropriate.

"We never intended the meaning of hard or porous surfaces to include such items as air ducts," Edwards said. She noted that the EPA is not setting out to cancel registrations, but to gather data to ensure that products are appropriately and effectively applied.

Duct cleaning professionals should be aware that only certified pest control operators may legally apply products classified as restricted use pesticides by EPA.

In the case of non-restricted antimicrobial products, local regulations may apply.

Application of antimicrobial products, including coatings, is becoming popular in the industry. Some contracting firms supplying duct cleaning services to government/military agencies include application of such products after cleaning in basic pricing.