Taste aversive agents
The bottom line
Taste aversive agents are unpleasant tasting substances often added to potentially dangerous chemicals with the intent of preventing poisoning from accidental ingestion by humans or pets. They are also used in over-the-counter products to help discourage nail-biting and thumb sucking; however, there is no evidence indicating that their usage decreases the incidence or severity of poisonings.
Prevention Tips
Do not rely solely on taste aversive agents to prevent unintentional ingestions.
Always store potentially harmful chemicals away from areas that could be easily accessed by children and pets.
Never transfer products from their original containers into unlabeled containers.
This Really Happened
A man called his poison center and reported that he does mask fitting tests using Bitrex Testing Solution (1% denatonium benzoate). The solution is bitter and, when they spray it on someone who is getting their mask fitted, the bitter taste will indicate that the mask is not properly fitted. The man reported that he’d been doing mask fittings all day lately because of COVID-19. When he gets home from work he feels nauseated and lightheaded. When he licks his lips, he can taste the bitter product, and he can also smell it. The poison center indicated that toxicity with this product is limited, but that it could be irritating especially with prolonged exposure. The poison center recommended that he rinse his skin and mouth well and felt that his symptoms should resolve gradually on their own. The following day, the poison center called the man and he reported that all of his symptoms had resolved.
The full story
Taste aversive agents are substances that are intentionally added to products to help deter inappropriate ingestion and prevent poisonings from occurring. One of the most common taste aversive agents is denatonium benzoate. You might also recognize it by one of its trade names—Denatrol, Bitrex, or Aversion. Denatonium benzoate has an extremely bitter taste that can be detected at minute concentrations (as low as 50 parts per billion). It has thus rightfully earned its reputation as “among the most bitter substances known to man” in the Merck Index and “the most bitter substance in the world” by the Guinness Book of World Records! Other common taste aversive agents include sucrose octaacetate and capsicum (chili peppers).
Some uses of taste aversive agents include:
As alcohol denaturants
In dangerous household chemicals such as:
Antifreeze
Animal repellents
Veterinary taste deterrent products
Rodent baits
Pesticides and weed killers
Detergents and disinfectants
Certain battery and device coatings (e.g., Nintendo Switch game cards)
Mask fitting testing
Nail-biting/thumb sucking deterrent products
Nail-biting and thumb sucking deterrent products found over-the-counter utilize taste aversive agents like denatonium benzoate and capsicum for their bitter and unpleasant taste properties to help break these habits. Taste aversive agents are generally considered safe with small ingestions.
Though the concept of adding taste aversive agents to substances is appealing, there is currently a lack of published data to demonstrate that adding these compounds to products actually reduces the incidence or severity of poisonings in humans and pets.
When it comes to taste aversive agents in chemicals, perhaps the more concerning potential toxicity would be the actual chemicals to which they are added. Many of these are highly toxic and the presence of a taste aversive agent might cause users to relax normal safety measures. For questions about potential poisonings related to taste aversive agents, use the webPOISONCONTROL® online tool or call 1-800-222-1222. Both options are free of the public, and available 24 hours a day.
