AUSTIN, TX — In mid-March, the U.S. Environmental Protection Agency (EPA) published a letter on the subject of “Use of Disinfectants and Sanitizers in Heating, Ventilation, Air Conditioning, and Refrigeration Systems.” Since then, experts from various business sectors have dissected and analyzed its contents.

The letter was the topic of discussion at one seminar at the recent Healthy Indoor Environments (HIE) 2002 Conference. In the letter, the EPA summarized its position:

“We recommend that you advise your members not to apply disinfectant, sanitizer, or other antimicrobial products to treat hvacr systems if such product does not include specific directions for hvacr use. The Agency believes that it is important that you ensure that members of your association are not applying products to hvacr systems which are not registered for that use.

“We intend to further evaluate this use to determine the potential exposure and risks, as well as the efficacy criteria which are required before pesticide products are registered to be used in hvacr systems.”


At HIE, EPA’s Dennis Edwards said that the actual work leading up to the published letter began in the early 1990s. “We are primarily concerned with sanitizing and disinfectant products which do not contain directions for use in air handling/ductwork,” he said. “We don’t have exposure data and have not assessed the risk of building occupants to antimicrobial products.”

Edwards said the EPA is concerned with users misinterpreting the labels and the fact that there are no specific directions for use in hvacr systems.

“Our proposed label recommendation would be: ‘Do not use in air ducts, air handlers, or ductwork of heating, ventilation, air conditioning or refrigeration systems.’”

Michael Bowdoin, an attorney with Brown & Simms, PC, Houston, TX, said there are legal implications from the restricted use of antimicrobial products in hvacr systems.

“My focus would be on the product, not the conduct of the user,” he said. “Is the product defective, e.g., its design or how it is marketed? Were directions followed? Was the disclaimer readable and understandable?”

Bowdoin added that suppliers should also take heed of the directions of use of the products they sell. “Texas statute says that manufacturers can indemnify the supplier if a product is defective — unless the supplier misapplies the product or adds to it [design change].”

In the end, Bowdoin said, “Make sure your product performs to the advertised claims.”

Bob Baker of BBJ Environmental Solutions, Inc., Tampa, FL, said that should the EPA “tighten the noose” on the use of antimicrobial products for hvacr systems, a typical response might be what one contractor said. “I will not use antimicrobials until this is cleared up,” Baker recounted. “This involves too much risk.”

“However,” Baker added, “manufacturers have said that this letter does not restrict the use of our products.”

Publication date: 06/03/2002