GIVE ME A BREAK! Formaldehyde down a septic system is okay? After reading Dave Bessmer’s article, you would think formaldehyde was safe to drink. Thetford Corporation is practically the only company in the country that says it’s safe for a septic system.

The EPS says it is “a probable carcinogen; moderately toxic to human (1).” OSHA reports formaldehyde causes known health hazards when touched, swallowed, or breathed (2). In 2004, the National Cancer Institute reports the International Agency for Reseach on Cancer (IARC) reevaluated the existing data that formaldehyde is a probable human carcinogen and reclassified it as a known human carcinogen (3). There are hundreds of other references against its use. In fact, Thetford holding tank deodorants have a warning in red letters, “This product contains a chemical known to the State of California to cause cancer.” This all boils down to, DON’T USE IT!

Formaldehyde either kills the good bacteria needed to liquefy solid wastes, or it has a preserving effect (embalm sound familiar?), preventing biological activitiy from occurring. This preserving effect can be p[revented by aerating the wastewater. This means septic systems need to provide added oxygen to make the formaldehyde dissappear so the bacteria can come out of suspended animation to do their job. If oxygen isn’t provided, the system stops working (4).

What can campgrounds do about providing added oxygen to their septic systems? Spend thousands of dollars for a better system to process maximum loads. THis is Thetford Corporations’ chief chemist’s solumtion to the problem. Or we can all help campground owners by not using formaldehyde.

Bessmer’s article says it’s okay the way the formaldehyde is going into the system as lomng as we RVers empty our tanks frequently using a lot of water. I agree. However, if you’re using a lot of water, why use a chemical that will eventually find its way into our water table?

Good try, Mr. Bessmer. Better luck next time.

— Preston Hall

(1) “RV Holding-tank Treatments & Deodorizers in Septic Systems,” by Kitt Farrell-Poe and Russ Radden, Cooperative Extension. The University of Arizona College of Agriculture and Life Sciences, June 2001

(2) “Formaldehyde,”

(3) “Cancer Facts Formaldehyde and Cancer: Questions and Answers,” National Cancer Institute, July 30, 2004

(4) “Effects of Recreational Vehicle Wastes on the Treatability of Domestic Wastewater,” by William Thomas, Florida Water Resources Journal, January 1995