Pest Solutions – Pesticide or Antimicrobial?

July 3, 1997

For the last several issues, we have discussed some of the legal concerns that contractors have today. That can be depressing. This issue, there is some good news. The United States Congress took an action last summer that results in a considerable reduction in legal risk. The new law allows contractors to use properly registered antimicrobial products as part of their maintenance strategy without fear of being accused of exposing someone to a dangerous Pesticide.

We receive many calls from contractors and their customers who are want to use an antimicrobial to control growth in their air conditioners but are confused by all of the negative statements that have been made about ‘Pesticides’ during recent years. Ever since Rachel Carson called attention to the dangers on DDT and other ogorano-phosphates in her book ‘Silent Spring’ there have been concerns about the risks associated with exposure to pesticides.

Pesticides Can Be Toxic

To some extent, such concerns are well placed. Many of the insecticides used to control crop destroying pests and insects around the home are highly toxic and can cause injury or discomfort to humans and animals if we are exposed to high concentrations or over long periods of time. In some cases, even short duration exposure can cause injury.

The chemical traits that allow antimicrobial products to destroy or control the growth of bacteria and other microorganisms can also result in irritation or toxicity in high concentrations. Fortunately, microscopic creatures can normally be effectively controlled at chemical concentrations that are well below the level, which would cause harm to humans or animals. In fact, most antimicrobial products will not even harm insects. They are not very effective pesticides.

Antimicrobials Are Different

The confusion results from the fact that in the past the U.S. government has used the same set of laws and regulations to regulate antimicrobials and pesticides. Thus the labeling, precautionary statements, and warnings on packages of both pesticides and antimicrobials look much alike. Although there are differences, they are not normally clear to the average consumer. During the summer of 1996, congress set out to correct that confusion. A law known as the ‘Food Quality Protection Act’ was passed and signed into law by President Clinton in August. Among other things, that law requires the EPA to set up a separate division to regulate Antimicrobials and establish a new set of regulations covering them. Although the new regulations will not be in place for another year and some time will be required for the full reality to filter throughout society, the new law will eventually remove much of the confusion.

The main sponsor of the bill in the Congress, Senator Rod Grams, summed it up best in his communication to the president urging approval of the bill:

‘Antimicrobials play an important and beneficial role in controlling disease and in maintaining a high public-health standard in hospitals, nursing homes, clinics, schools, hotels, restaurants, and even in our own homes.’

Does this mean that any antimicrobial is therefore, safe to use in an air conditioning system? No! Even though Antimicrobials are generally safer than many other products, they still must have a certain level of activity to be effective. Many of the Antimicrobials that are developed for use in hospitals and on countertops and in rest rooms must work quickly to be fully effective. Therefore, they are formulated with ingredients that are highly active and may be too irritating to use where they may enter into the air stream and be inhaled.

Follow Directions

Before selecting a product to use, read the label carefully. If the directions do not specifically provide for use in air-conditioning systems, do not use it. The agency is working to clarify label language on products that were previously confusing. They are also working do develop criteria that may allow additional products to be specifically registered for HVAC applications. Until that takes place, it is best to ask a lot of questions and be sure of what you are buying and using.

The Law Limits Your Liability

One of the good things about the EPA regulatory process is that when you use a registered product according to the directions on the label, your liability from any alleged injury caused by that proper use is limited. The EPA has certified that the product is safe and effective to use in that manner. Therefore, a court will not find that you have done something improper. That can be an important protection given the attitudes we often encounter in society today.

Bob Baker is a member of ASHRAE and Chairman and CEO of BBJ Environmental Solutions, Inc., a manufacturing company specializing in providing clean air through environmentally responsible products, such as BBJ MicroBiocideâ„¢, BBJ Micro Coil Cleanâ„¢, BioSoft Spray Disinfectant/Cleanerâ„¢, and Fresh Ductâ„¢, as well as The Indoor Air First Aid Kitâ„¢. For additional information, Mr. Baker can be reached at (800) 889-2251 or through the company web site at