Poisoning Interventions

Bittering Agents

Another intervention aimed at preventing accidental poisonings is the addition of a harmless agent that would make poisonous household liquids taste so foul and bitter that children would not continue to ingest the substance. Denatonium benzoate (Bitrex) has been suggested as the ideal compound for such an intervention: it is non-toxic, chemically stable, and the most bitter substance known (50-100 ppb is sufficeint to be tasted as bitter).

While several stuides exist that examine children’s reactions to this bittering agent,13-16 at this time, there are no studies that examine the effectiveness of bittering agents in preventing childhood poisonings in the real world.

Review of physician-based education studies:


Neumann et al, 2000

Study design and target population

Ecological time series.

State of Oregon, children under 6.


1991 Oregon law which required that anti-freeze and windshield washer fluid must contain an aversive agent after April 1995.


Reports of poisoning to the Poison Center.


No significant effect on number of cases reported.

Study quality and conclusions

Poor design and small number of cases limits conclusions which can be drawn.

Summary of bittering agent studies

The one study above did not provide any evidence for the impact of the law. The study was a weak design with small numbers of cases and no concurrent control.

Recommendations for future research

Other studies should be undertaken of the Oregon Law. There is also a need for a large RCT of bittering agents.