Does Food nanoparticles (titanium dioxide E171) cause infertility?

Probable. Several human studies point the same way, with a plausible biological mechanism, but the evidence is not yet conclusive. Nanoparticles (under 100 nm) penetrate the body more easily; animal studies have shown placental crossing, which prompted a precautionary ban — EFSA (European Food Safety Authority) cannot establish a safe daily dose.

Food nanoparticles (titanium dioxide E171)

Nanoparticulate additive

Evidence level : Probable Snacks & ready mealsMechanism : Dietary / inflammatory burden

🟡 Several human studies point the same way, with a plausible biological mechanism, but the evidence is not yet conclusive.

Where it's found: Banned from food in France since 2020 and across the EU since 2022, but still found in illegally imported products (confectionery, industrial pastries); still permitted in some medicines and cosmetics.
Suspected mechanism: Nanoparticles (under 100 nm) penetrate the body more easily; animal studies have shown placental crossing, which prompted a precautionary ban — EFSA (European Food Safety Authority) cannot establish a safe daily dose.
Suggested alternative: Check ingredient lists (E171 or titanium dioxide) on products imported from outside the EU; the European ban has greatly reduced exposure since 2022.
Source: EFSA 2021; ANSES 2019; INRAE study (Bettini et al., NANOGUT); INRAE ASIRPA 2025.

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Related factors

Including a factor does not mean it causes infertility: it is simply worth monitoring, depending on its level of evidence.

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Content last updated: September 14, 2026