Background: Legislation requiring bittering of antifreeze enables assessment of the impact on frequency, volume, and severity of pediatric antifreeze ingestions.
Methods: US poison control data for antifreeze ingestions in children younger than 5 years were analyzed comparing 232 ingestions occurring in states after enactment of bittering requirements with 6218 cases occurring in states (or at times) where bittering was not required.
Results: The frequency of pediatric antifreeze ingestions was unchanged after implementation of bittering in Oregon and California. The medical outcome distribution, median volume ingested, and observed clinical effects were no different in bittered compared with nonbittered groups. Likewise, the rates of hospital admission, critical care treatment, and use of alkalinization, hemodialysis, or intubation showed no differences with bittering.
Conclusion: Despite the appealing logic of limiting the ingested volume and thereby the severity of poisonings by adding aversive agents, and despite promising results in volunteer studies, bittering agents do not decrease the frequency or severity of pediatric antifreeze poisonings. The addition of bittering agents to household products cannot be justified based on actual poisoning data.