TKS Fluid Toxicity

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I am considering adding TKS to a Bonanza G36, but am concerned about
the toxicity of the TKS fluid.

The standard fluid (TKS 406B) contains ethylene glycol, which is
antifreeze and is deadly if ingested. I am particularly concerned
because I have my dogs around and in the airplane and dogs are
unfortunately attracted to the smell and taste of antifreeze.

TKS also makes 3 other versions: TKS 80, R328, and TKS Sustain.
These are described as "glycol-based", but they never say if it is
ethylene glycol (EG), which is highly toxic, or propylene glycol
(PG), which is non-toxic.

I tried e-mailing Kilfrost (who makes TKS and is the K in the name)
and their U.S. affiliate, but I never got a reply. Any help or input
would be appreciated.


-- Todd Ramming, May 27, 2010


I have a 1998 Mooney Encore with factory-installed TKS and would never buy a similar plane without it.

I purchase AL-5 (406B) from CAV Aerospace in Salina, KS. Their website is and maybe they have more information for you.

AL-5 is toxic but comes in sturdy containers that are difficult to open. The greatest danger is probably after a flight when you've used TKS - excess fluid will drip off your plane and onto the floor of your hangar. Also be careful when filling... I overfilled once and the fluid came out of the vent in the tank and left a big puddle on the floor.

If you can find a way to manage your dogs you'll find that TKS's benefits to every creature that enters your plane to be substantial. I've been able to make dozens of flights over the past 10 years with the system that I could not have made without it, and I know it has saved my life at least twice when I flew into icing situations that were much more severe than forecast.

-- Joe Zuffoletto, May 31, 2010


My name is David Schueler and I work for the Americas office at Kilfrost in Florida. Your e-mail posting had no contact information associated with it except the link to this web site. Concerning your TKS question, please call me at 954-282-5045 and I would be more than happy to address your points.

I look forward to hearing from you.

Best regards,

David Schueler Kilfrost, Inc. 954-282-5045

-- David Schueler, June 1, 2010

I called Kilfrost at the number David provided and they were able to answer my questions. I had read previously about TKS Sustain, their new environmentally friendly TKS fluid. According to an AOPA article, "(TKS Sustain) will have some big advantages over the traditional TKS fluid. It will weigh 10 percent less, making a gallon weigh 8.3 pounds instead of TKS 408B�s 9.2 pounds. Its viscosity characteristics are better, too. TKS Sustain will stay thinner at colder temperatures and be slightly thicker at warmer temperatures. On the down side, TKS Sustain will cost 10 to 20 percent more per gallon." (

Kilfrost told me that TKS Sustain uses a bioglycol (not ethylene glycol), which is listed on the Material Safety Data Sheet as non-toxic. The only substance TKS Sustain contains that is listed with a warning is ethyl alcohol (drinking alcohol), which obviously produces symptoms of intoxication if ingested.

Kilfrost also told me that TKS Sustain is awaiting final FAA approval and should be available before the upcoming fall/winter season. It will be sold, like TKS 406B, from CAV Aerospace in Salina, KS.

Finally, TKS Sustain has a lower freezing point (better performance) than TKS 406B.


-- Todd Ramming, June 3, 2010