High concern

BHA & BHT

Butylated hydroxyanisole · Butylated hydroxytoluene · E320 · E321

Synthetic antioxidant preservatives added to fats and oils to extend shelf life. Both have been restricted or banned in much of the world — but remain common in American breakfast cereals, snack foods, and packaged baked goods.

Why we flag them

BHA is classified by the U.S. National Toxicology Program as "reasonably anticipated to be a human carcinogen" based on consistent evidence of cancer in animal studies. The International Agency for Research on Cancer (IARC) lists BHA as Group 2B — "possibly carcinogenic to humans." BHT, while less studied, has shown similar effects at high doses in animal research and is suspected of being an endocrine disruptor.

Both compounds are banned in infant foods across the European Union and prohibited in food entirely in Japan, Australia, and several other countries. Many U.S. brands have voluntarily removed them — General Mills, Kellogg's, Mars, and Nestlé have all announced phase-outs — but they remain in plenty of products on store shelves.

Where you'll find them

Anywhere fats need to stay stable on the shelf for months:

What to look for instead

Cleaner preservation methods are widely available — many brands have already switched:

The best signals on a label: "preserved with mixed tocopherols," "no artificial preservatives," or USDA Organic certification, which prohibits BHA and BHT entirely.