Fish oil is used as an ingredient in fish feed, and consequently BHA may be present in fish feed. BHA is authorised as a food additive for several food products such as cake mixes, snacks and powdered milk. Since low levels of BHA are present in fish feed, very low concentrations are present in farmed salmon.
BHA has not been found to have harmful effects on humans, but studies on rats have shown that it may be carcinogenic if consumed at high doses.
There are no maximum levels for BHA in fish. The acceptable daily intake of BHA derived by the European Food Safety Authority is 1 mg per kg body weight per day. A large portion (300 grams) of farmed salmon would contribute less than 0.05 per cent of the acceptable daily intake of BHA. The intake of BHA from the consumption of farmed salmon is negligible.
Threshold values in fish feed
In fish feed, the maximum level for the sum of synthetic antioxidants (EQ, BHA, BHT, PG and OG) is 150 milligrams per kilograms of feed. The levels of BHA in fish feed is monitored by the Norwegian Food Safety Authority in a feed monitoring programme, no feeds analysed to date have contained BHA levels which exceed the maximum level, and levels are considerably lower than those for BHT and ethoxyquin.