Problematic additives
BHA (E320)
Avoid
Description
Synthetic antioxidant preservative.
Benefits
Preserves fats
Risks
Suspected carcinogen, endocrine disruptor
History and origin
Butylated hydroxyanisole (BHA) was first synthesised in 1947 as an industrial antioxidant for rubber and petroleum products. It was approved as a human food preservative in 1954 and entered pet food shortly after. For forty years it was the default antioxidant in dry pet food because it was extremely cheap and extended shelf life from 6 months to 18 months. Starting in the 1980s, peer-reviewed studies linked BHA to tumour development in rodent studies, and the International Agency for Research on Cancer classified it as possibly carcinogenic to humans in 1987. Japan banned it from human food in 1958. The EU restricts its use in human food but still permits it in pet food.
Controversies and what to watch for
The pet food industry's argument for keeping BHA is that the dose in pet food is below the level that causes tumours in rats. The counter-argument is that cats and dogs eat the same brand every day for 10 to 15 years, which means cumulative exposure is far higher than the short-term rat studies measure. Natural alternatives exist and work perfectly: mixed tocopherols (vitamin E), rosemary extract, and ascorbic acid (vitamin C) preserve kibble for 10 to 12 months with zero carcinogenic concern. Premium brands all switched to natural antioxidants in the 2000s. BHA is now found only in budget brands where the extra few cents of cost matter.
Species adaptability
Avoid for
- Dogs
- Cats
- Rabbits
- Ferrets
- Birds