Potassium Sorbate vs Butylated Hydroxytoluene: which is worse?

What is Potassium Sorbate?

Potassium sorbate is the potassium salt of sorbic acid, a naturally occurring short-chain fatty acid originally derived from the mountain ash berry (Sorbus aucuparia). Commercial potassium sorbate is synthetically produced by reacting sorbic acid with potassium hydroxide. It is the most widely used food preservative globally.

What is Butylated Hydroxytoluene?

Butylated hydroxytoluene (BHT) is a synthetic lipophilic phenolic antioxidant preservative derived from petroleum. It is a white crystalline solid with chemical formula C15H24O. Like BHA, it prevents fat oxidation and is widely used in food, cosmetics, pharmaceuticals, jet fuel, and rubber.

Documented risks

Potassium Sorbate: Potassium sorbate has a generally good safety profile compared to other synthetic preservatives. EFSA's 2015 re-evaluation maintained the ADI at 3 mg/kg body weight, finding no significant carcinogenicity or genotoxicity. However, some human and in vitro studies have documented concerns. A 2010 study in Toxicology in Vitro found potassium sorbate was genotoxic (caused DNA strand breaks) in human blood cells at concentrations achievable in food. The study found it damaged peripheral blood lymphocytes. A 2014 study in Food and Chemical Toxicology found potassium sorbate caused DNA damage in human lymphocytes at food use concentrations. Contact dermatitis and allergic reactions from topical use are documented. At very high doses in animal studies, liver and kidney effects have been observed. The general regulatory consensus is that potassium sorbate is one of the safer food preservatives, but the in vitro genotoxicity findings deserve attention.

Butylated Hydroxytoluene: BHT's carcinogenicity profile is complex and bidirectional. Some NTP bioassays found liver tumors in female mice at high doses, while other studies suggested BHT might inhibit tumor initiation in certain contexts. A 1986 NTP bioassay found liver tumors in female mice but anti-carcinogenic effects in the rat forestomach — making BHT's net carcinogenicity uncertain. IARC has not formally classified BHT in a specific Group due to this conflicting evidence. The NTP notes that BHT's carcinogenicity data are complex. The 'Report on Carcinogens' does not currently list BHT, unlike BHA, but the NTP has noted inconclusive evidence. Potential endocrine disruption: a 2017 study in Environmental Science & Technology found BHT disrupted thyroid hormone levels in female rats. Multiple animal studies have demonstrated weak estrogenic effects. The American Academy of Pediatrics' 2018 policy statement on food additives mentioned BHT as a synthetic preservative warranting reduced childhood exposure. Kellogg's Frosted Flakes in the US contains BHT to preserve freshness; the European version uses mixed tocopherols (vitamin E) instead — a commercially meaningful difference demonstrating feasibility of substitution. Japan banned BHT for food use based on its precautionary approach. The EU restricts it with ADI-based maximum permitted levels.