BHA / BHT
Also known as: butylated hydroxyanisole, butylated hydroxytoluene
Synthetic petroleum-derived preservatives used to stop fats in kibble from going rancid.
What it actually is
Butylated hydroxyanisole and butylated hydroxytoluene — synthetic antioxidants developed for the petroleum industry in the 1940s and later adopted by food manufacturers.
Why it's used in dog food
Extremely effective at preventing fat oxidation in shelf-stable kibble. Cheap, and lets a bag sit on a shelf for 12+ months without turning rancid.
A bit of history
Introduced to human food in the 1940s. Classified by the US National Toxicology Program as 'reasonably anticipated to be a human carcinogen' in 1991. Banned or restricted for pet food in several EU countries. Still legal in North America.
Pros
- •Very effective preservative — extends kibble shelf life significantly
- •Cheap
Cons
- •Classified as reasonably anticipated to be a human carcinogen (US NTP)
- •Banned from pet food in Japan and restricted in parts of the EU
- •Studies in rats and mice show liver and stomach tumours at high doses
- •Natural alternatives (mixed tocopherols, rosemary extract) work well
Safety notes
Any food using natural preservatives (mixed tocopherols, rosemary extract, ascorbic acid) is a better choice.
Sourcing & quality
Any food that lists BHA, BHT, or ethoxyquin is a lower-quality formulation regardless of what else is on the label.
Commonly found in
Skip this if…
Always — choose a food preserved with mixed tocopherols instead.
The verdict
Avoid. There is no ingredient more universally worth swapping out.