Denatonium benzoate is one of the most bitter substances known. Just a few parts per million will make a product so bitter that children and pets will not be able to swallow it. Denatonium benzoate makes sweet but highly toxic products such as antifreeze and detergents taste foul. Research shows that people can detect denatonium benzoate in water at 50 parts per billion. Denatonium benzoate is bitter at 1 to 10 ppm and most products will become undrinkable at 30 to 100 ppm. Denatonium benzoate is also stable and inert. In addition, so little is needed that the properties of the product remain unchanged.

Aversion Technologies offers denatonium benzoate in four forms:

– 100% denatonium benzoate powder – in 1 kg bags or in 25 kg drums

– 100% denatonium benzoate prill (dustless noodles) – in 1 kg bags or in 25 kg drum

– 25% denatonium benzoate in ethylene glycol (w/v) – in 5 liter jugs

– 25% denatonium benzoate in propylene glycol (w/v) – in 5 liter jugs

Both the National Safety Council and the American Medical Association recommend adding denatonium benzoate to products that are defined as mild to moderately toxic. Some countries like France have made denatonium benzoate mandatory in antifreeze. Others such as Italy have made denatonium benzoate the number one denaturant for ethanol. The State of Oregon has required that it be added to antifreeze and windshield wiper fluid since 1995.


Chemical names

A) Denatonium Benzoate

B) Ammonium, Benzyl diethyl ((2,6,Xylylcarbamoyl) methyl)-Benzoate

CAS Registry Number: 3734-33-6

Molecular Formula: C28 H34 N2 O3


Appearance: White powder

Melting point: 163 – 170°C

Acidity (3% solution): pH 6.5 – 7.5

Loss on drying: 1.0% max

Sulfated Ash: 0.1% max

Chloride: 80ppm max