Butylated Hydroxytoluene vs Titanium Dioxide: which is worse?

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.

What is Titanium Dioxide?

Titanium dioxide (TiO2) is a naturally occurring white mineral used as a food colorant, whitening agent, and opacity enhancer. In food applications, it exists as nano-sized and micro-sized particles. It is one of the most widely produced industrial minerals globally, used in paints, plastics, sunscreens, and food products.

Documented risks

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.

Titanium Dioxide: The EU banned titanium dioxide as a food additive in 2022 following EFSA's landmark 2021 safety assessment (EFSA Journal 2021;19(5):6585), which concluded that titanium dioxide 'can no longer be considered safe as a food additive.' The primary concern is genotoxicity from nanoparticles: EFSA determined it was impossible to rule out the risk of DNA damage (genotoxicity) from TiO2 nanoparticles at typical food use exposure levels. In vitro studies have demonstrated that TiO2 nanoparticles cause DNA strand breaks in intestinal epithelial cells and induce oxidative stress. A 2019 study in Nature Communications found TiO2 nanoparticles could disrupt gut microbiome balance and intestinal barrier function in mice models. Multiple studies have suggested effects on gut permeability and immune function. IARC classifies titanium dioxide as Group 2B (possible human carcinogen) for inhalation exposure in occupational settings — primarily relevant to workers handling TiO2 dust, based on rat lung cancer studies. While inhalation and oral exposure are different routes, EFSA determined that the genotoxicity concerns from nanoparticles applied to oral food use as well. Following the EU ban, California attempted to pass legislation banning TiO2 in candy (along with other additives) in 2022. The bill was signed in modified form. Mars reformulated EU Skittles to remove TiO2. The US FDA has not announced specific action on food-grade TiO2 as of 2025, though USRTK and other organizations are calling for a US ban.