Titanium Dioxide vs Propyl Gallate: which is worse?

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.

What is Propyl Gallate?

Propyl gallate is a synthetic antioxidant preservative derived from gallic acid and propanol. It prevents oxidation of fats and oils, extending shelf life of fat-containing foods. It is often used in combination with BHA and BHT for synergistic antioxidant effect. Chemical formula: C10H12O5.

Documented risks

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.

Propyl Gallate: Animal studies have shown propyl gallate may cause liver damage at high doses. Concerns about estrogenic activity have been raised — some studies suggest propyl gallate may weakly mimic estrogen. Contact dermatitis and allergic reactions are documented in both food and cosmetic applications. Japan banned propyl gallate for food use as part of its precautionary approach to synthetic food preservatives. NTP bioassays found dose-dependent liver effects. EFSA's re-evaluation set an ADI of 0.1 mg/kg body weight — one of the lowest ADIs for food additives, reflecting toxicological concern.