Titanium dioxide (nano form) in the yard and garden
Low risk for your yardTitanium dioxide (TiO₂) is the most widely used white pigment globally, found in paints, coatings, plastics, cosmetics, sunscreens, and food products (formerly E171 in the EU). The IARC Group 2B classification for TiO₂ is specific to inhaled ultrafine/nano particles and does NOT apply to oral ingestion or dermal application. For consumer sunscreen use — the primary personal care exposure route — dermally applied TiO₂ (both conventional and nano form) does not penetrate intact healthy skin in biologically significant quantities; photon microscopy and SIMS (secondary ion mass spectrometry) studies confirm TiO₂ remains largely in the stratum corneum and does not reach viable skin cells. The EU banned E171 (TiO₂ as a food additive) in 2022 under Regulation (EU) 2022/63 based on EFSA's 2021 opinion that TiO₂ could not be considered safe as a food additive given genotoxicity concerns from oral nanoparticle exposure in animal studies. The FDA has not banned TiO₂ as a food additive in the US. For sunscreen and cosmetic use, TiO₂ (including nano form) is FDA GRASE and considered safe, with the caveat that inhalation of spray sunscreen or powder formulations containing TiO₂ nano particles should be minimized. TiO₂ in conventional macro-form used as a pigment in paints and opaque products presents no meaningful cancer risk via normal consumer use.
What is titanium dioxide (nano form)?
The IUPAC name is dioxotitanium.
Also known as: dioxotitanium, TITANIUM DIOXIDE, Titania, Titanium(IV) oxide.
- IUPAC name
- dioxotitanium
- CAS number
- 13463-67-7
- Molecular formula
- O2Ti
- Molecular weight
- 79.866 g/mol
- SMILES
- O=[Ti]=O
- PubChem CID
- 26042
Risk for people, pets,
Low riskTitanium dioxide (TiO₂) is the most widely used white pigment globally, found in paints, coatings, plastics, cosmetics, sunscreens, and food products (formerly E171 in the EU). The IARC Group 2B classification for TiO₂ is specific to inhaled ultrafine/nano particles and does NOT apply to oral ingestion or dermal application. For consumer sunscreen use — the primary personal care exposure route — dermally applied TiO₂ (both conventional and nano form) does not penetrate intact healthy skin in biologically significant quantities; photon microscopy and SIMS (secondary ion mass spectrometry) studies confirm TiO₂ remains largely in the stratum corneum and does not reach viable skin cells. The EU banned E171 (TiO₂ as a food additive) in 2022 under Regulation (EU) 2022/63 based on EFSA's 2021 opinion that TiO₂ could not be considered safe as a food additive given genotoxicity concerns from oral nanoparticle exposure in animal studies. The FDA has not banned TiO₂ as a food additive in the US. For sunscreen and cosmetic use, TiO₂ (including nano form) is FDA GRASE and considered safe, with the caveat that inhalation of spray sunscreen or powder formulations containing TiO₂ nano particles should be minimized. TiO₂ in conventional macro-form used as a pigment in paints and opaque products presents no meaningful cancer risk via normal consumer use.
Regulatory consensus
11 regulatory and scientific bodies have classified Titanium dioxide (nano form). The classifications differ — that's the data.
| Agency | Year | Classification | Notes |
|---|---|---|---|
| IARC | 2010 | Group 2B (possibly carcinogenic to humans) | IARC Monograph 93 (2010). Titanium dioxide classified Group 2B specifically for the nano/ultrafine form via inhalation — based on sufficient evidence for carcinogenicity in animals (inhalation studies in rats showing lung tumors attributed to 'particle overload' at high doses) and inadequate evidence in humans. The classification applies to inhaled TiO₂ particles and is NOT based on dermal or oral exposure. The carcinogenic mechanism is considered to be particle overload in the lung at high doses, not specific chemical toxicity — the IARC Working Group noted this is shared by other poorly soluble particles. The 2B classification does NOT apply to dermally applied TiO₂ in sunscreens, where TiO₂ does not penetrate intact skin to a biologically meaningful extent. IARC explicitly noted that dermal application routes are not relevant to the 2B classification. |
| EPA CTX / NIOSH | — | potential occupational carcinogen | |
| EPA CTX / IARC | — | Group 2B - Possibly carcinogenic to humans | |
| EPA CTX / Genetox | — | Genotoxicity: positive (Ames: positive, 17 positive / 6 negative reports) | |
| EPA CTX / Genetox | — | Genotoxicity: positive (Ames: positive, 17 positive / 6 negative reports) | |
| EPA CTX / Skin-Eye | — | Skin Irritation: Not classified (score: low) | |
| EPA CTX / Skin-Eye | — | Skin Sensitization: Not classified (score: low) | |
| EPA CTX / Skin-Eye | — | eye irritation: in vivo: Studies Indicate No Significant Irritation (score: low) | |
| EPA CTX / Skin-Eye | — | skin irritation: in vivo: Studies Indicate No Significant Irritation (score: low) | |
| EPA CTX / Skin-Eye | — | skin sensitisation: in vivo (LLNA): Not likely to be sensitizing (score: low) | |
| EPA CTX / Skin-Eye | — | skin sensitisation: in vivo (non-LLNA): Not likely to be sensitizing (score: low) |
Regulators apply different standards of evidence — animal-data weighting, exposure-pattern assumptions, epidemiological power thresholds — which is why two scientific bodies can review the same data and reach different conclusions. The disagreement is the data.
Where your yard encounter titanium dioxide (nano form)
- Outdoor Air — Vehicle exhaust, Industrial emissions, Power plant discharge
- Indoor Air — Combustion byproducts, Office buildings, Parking garages
- Personal Care — sunscreen, moisturizer with SPF, foundation, lip balm
Safer alternatives
Lower-risk approaches that achieve a similar outcome to Titanium dioxide (nano form):
-
Physical/mechanical pest control (IPM)
Trade-offs: More labor-intensive. May not be sufficient for severe infestations.Relative cost: 1.2-2×
-
Zinc oxide
Relative cost: 1.2-2×
-
Iron oxides
Relative cost: 1.2-2×
Frequently asked questions
Is titanium dioxide (nano form) safe for your yard?
Titanium dioxide (TiO₂) is the most widely used white pigment globally, found in paints, coatings, plastics, cosmetics, sunscreens, and food products (formerly E171 in the EU). The IARC Group 2B classification for TiO₂ is specific to inhaled ultrafine/nano particles and does NOT apply to oral ingestion or dermal application. For consumer sunscreen use — the primary personal care exposure route — dermally applied TiO₂ (both conventional and nano form) does not penetrate intact healthy skin in biologically significant quantities; photon microscopy and SIMS (secondary ion mass spectrometry) studies confirm TiO₂ remains largely in the stratum corneum and does not reach viable skin cells. The EU banned E171 (TiO₂ as a food additive) in 2022 under Regulation (EU) 2022/63 based on EFSA's 2021 opinion that TiO₂ could not be considered safe as a food additive given genotoxicity concerns from oral nanoparticle exposure in animal studies. The FDA has not banned TiO₂ as a food additive in the US. For sunscreen and cosmetic use, TiO₂ (including nano form) is FDA GRASE and considered safe, with the caveat that inhalation of spray sunscreen or powder formulations containing TiO₂ nano particles should be minimized. TiO₂ in conventional macro-form used as a pigment in paints and opaque products presents no meaningful cancer risk via normal consumer use.
What products contain titanium dioxide (nano form)?
Titanium dioxide (nano form) appears in: Vehicle exhaust (Outdoor air); Industrial emissions (Outdoor air); Combustion byproducts (Indoor air); Office buildings (Indoor air); sunscreen (Personal care).
Why do regulators disagree about titanium dioxide (nano form)?
Titanium dioxide (nano form) has been classified by 11 agencies including IARC, EPA CTX / NIOSH, EPA CTX / IARC, EPA CTX / Genetox, EPA CTX / Genetox, with differing conclusions. Regulators apply different standards of evidence (animal data weighting, exposure-pattern assumptions, epidemiological power thresholds), which is why two scientific bodies can review the same data and reach different conclusions. See the regulatory consensus table on this page for the full picture.
See Titanium dioxide (nano form) in the outdoor app
Look up products containing titanium dioxide (nano form), compare to alternatives, and explore the full data record.
Open in outdoor View raw API dataSources (2)
- IARC Monographs Volume 93: Carbon Black, Titanium Dioxide, and Talc — Titanium Dioxide Group 2B Evaluation (Inhalation, Nano Form) (2010) — regulatory
- EFSA: Re-evaluation of Titanium Dioxide (E 171) as a Food Additive — Safety Opinion and EU Ban Basis (2021) — regulatory
Reference data, not professional advice. Aggregates publicly available regulatory and scientific data; not a substitute for veterinary, medical, legal, or regulatory advice. Why we built ALETHEIA →