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Denatonium Benzoate

  • Other
  • CAS 3734-33-6
  • IUPAC: benzyl-diethyl-[(2,6-xylylcarbamoyl)methyl]ammonium benzoate

Denatonium Benzoate (CAS 3734-33-6) appears in 1 of the 1,812 car-care products CarCareTruth tracks (as of June 2026).

Denatonium benzoate is added at very low concentrations (typically 1-100 ppm) as a bittering agent to deter accidental ingestion of household and industrial products. It carries H302 (harmful if swallowed) at concentrated form but is functionally effective at concentrations far below any toxicological threshold. Not a skin sensitizer, not a carcinogen, not on California's Prop 65 list. Its presence in a product is a consumer safety feature — it signals the manufacturer is taking steps to reduce accidental ingestion risk.

Denatonium benzoate (BITREX) is the most bitter substance known, detectable by humans at concentrations as low as 8 ppm. It is added to antifreeze, cleaning products, industrial fluids, and nail-biting deterrents as an aversion agent to prevent accidental ingestion. Its presence in a cleaning product is a safety-positive formulation choice. At typical use concentrations in cleaning products (often under 10 ppm) there are no realistic health concerns from skin or inhalation exposure.

Regulatory status

  • Not CA Prop 65 listed
  • EU CLP: H302 (harmful if swallowed) at concentrated form only
  • Approved as denaturant in multiple jurisdictions

Health & environment profile

VOC
no
Prop 65 listed
no
Asthmagen
no
EPA Safer Choice
no
Aquatic toxicity
no
Biodegradable
no
Bioaccumulative
no
Persistent
no
Ozone depleting
no
Microplastic
no
PFAS
no
Env. score
5/5
Purpose: Aversion agent (bittering agent) added to cleaning products and industrial fluids to prevent accidental ingestion; among the most bitter substances known

Common questions about Denatonium Benzoate

What is Denatonium Benzoate used for in car care?
Aversion agent (bittering agent) added to cleaning products and industrial fluids to prevent accidental ingestion; among the most bitter substances known
Is Denatonium Benzoate a VOC?
No. Denatonium Benzoate is not classified as a volatile organic compound (VOC).
Is Denatonium Benzoate on California's Proposition 65 list?
No. Denatonium Benzoate is not on California's Proposition 65 list.

1 product contain this

Related

Health and environment notes translate the manufacturer Safety Data Sheet, the GHS classification, and authoritative regulatory listings (California Prop 65, EPA). Not medical advice. They describe the ingredient itself; whether a hazard applies to a finished product depends on its concentration and how it's used.