EU risk assessor hikes intake safety levels for food additive BHT

The European food safety assessor has revised upward the acceptable daily limit for food additive used in chewing gum and fats and oils - BHT.

Exposure of adults to the synthetic antioxidant - butylated hydroxytoluene (BHT) (E 321) - is unlikely to exceed the newly derived ADI of 0.25 mg/kg bw/day at the average and high end consumer intake level, said the European Food Safety Authority (EFSA).

The EFSA Panel concluded that BHT is not of concern with respect to genotoxicity or carcinogenicity.

BHT prevents oxidative rancidity of fats. It is used to preserve food odour, colour, and flavour. It is also added directly to shortening, cereals, and other foods containing fats and oils. In addition, it is permitted in chewing gum alone or in combination with other synthetic antioxidants at a maximum level of 400 mg/kg chewing gum.

EFSA said its panel on Food Additives and Nutrient Sources added to Food (ANS) re-evaluated the safety of the additive as part of the programme set up under Regulation (EU) No 257/2010. This legislation ensures that food additives are re-evaluated whenever necessary in light of changing conditions of use and new scientific information.

The Panel said it was not provided with a newly submitted dossier and that based its risk assessment on previous evaluations, additional literature that became available since then and the data available following a public call for information.

Earlier assessments

BHT had previously been reviewed by the Joint FAO/WHO Expert Committee on Food Additives (JECFA), the latest in 1996, and also the EU Scientific Committee for Food (SCF) in 1987.

The SCF had established an ADI of 0-0.05 mg/kg bw/day for the additive based on thyroid, reproduction and haematological effects in the rat, while JECFA allocated an ADI of 0-0.3 mg/kg bw/day for BHT based on effects in the reproduction segments and hepatic enzyme induction seen in two separate 2-generation studies in rats.

The Parma-based risk assessor said that after the last SCF evaluation, two new 2-generation studies were published, which were the basis for the ADI set by JECFA. Both studies revealed a NOAEL of 25 mg/kg bw/day. 

“Overall, the Panel concluded that the present database gives reason to revise the ADI of 0.05 mg/kg bw/day. Based on the NOAEL of 25 mg/kg bw/day and an uncertainty factor of 100, the Panel derived an ADI of 0.25 mg/kg bw/day,” said EFSA.

Worst-case scenario

Using a worst-case scenario of combined exposure to BHT from the food categories where its use is authorised, the ANS experts estimated that potential exposure for adults to be on average 0.01-0.03 mg/kg bw/day and 0.03-0.17 mg/kg bw/day at the 95th percentile - the highest exposure level.

For children, the scientists estimated potential exposure in the range of 0.01-0.09 mg/kg bw/day at the mean and in the range of 0.05-0.30 mg/kg bw/day at the higher exposure range.

The Panel noted that at the average exposure of adults to BHT is unlikely to exceed the newly derived ADI of 0.25 mg/kg bw/day and at the 95th percentile.

For exposure of children to BHT from its use as food additive, the ANS found that it is also unlikely that this ADI is exceeded at the mean, but is, in fact, exceeded for some European countries such as Finland, and the Netherlands, at the highest intake levels.