Triphenyl Phosphate in Nail Polish: 2026 Guide

Triphenyl phosphate (TPHP, also written TPhP) is a chemical plasticizer that has been found in some nail polishes. California has now added nail products with more than 250 parts per million (ppm) TPHP to its Safer Consumer Products priority list. That is a new regulatory step—not a blanket ban on nail polish or an instruction that consumers must discard products. [1][2][5]

The European Union has taken a separate route: its 2026 cosmetics regulation adds TPHP to the list of prohibited substances, with transition dates for products that do not meet the new rules. If you have seen headlines about TPO in gel nails, that is yet another chemical with a different identity and legal history. This guide separates those developments and explains what consumers can reasonably take from the evidence.

What Is TPHP, and Why Is It in Nail Polish?

TPHP (CAS 115-86-6) is a phosphate ester used for several industrial functions, including as a plasticizer and flame retardant. In polish, it has been used to help make a coating flexible. It is not present in every nail product, and the amount can vary by formula. The California rule applies to a defined product-and-chemical combination, not to all products marketed as nail polish.

Ingredient lists can help identify a product that declares “triphenyl phosphate” or “TPHP,” but a label generally does not tell you the concentration in ppm. Therefore, the presence of the ingredient name alone cannot establish whether a particular formula is above California’s 250 ppm threshold. Conversely, absence from a label is not a laboratory measurement of the product. Some older research found TPHP in products whose labels did not disclose it, which is one reason not to treat a label as a chemical test. [5]

What California’s October 2026 Listing Does

As of October 1, 2026, California’s regulations list nail products containing TPHP above 250 ppm as a Priority Product under the state’s Safer Consumer Products program. The approved rule adds section 69511.10 to Title 22 of the California Code of Regulations; the Office of Administrative Law’s effective-date listing records the action, and the state CEQA notice describes the threshold and product category. [1][2]

“Priority Product” is a designation that starts a manufacturer compliance process; the listing itself is not a statewide sales ban or consumer discard notice. Manufacturers must notify DTSC if their product meets the definition. The CEQA notice describes possible routes: remove TPHP, replace it, stop California sales, or conduct an alternatives analysis. DTSC does not mandate one response simply by listing the product. [1]

The 250 ppm cutoff defines this listing’s scope, not a safety boundary. A product below it is outside this specific listing, but that alone does not establish that it is risk-free. In-scope status likewise does not mean every user will experience harm; further regulatory responses, if any, follow later review. [1]

For consumers, the practical near-term limitation is simple: most labels do not provide a measured ppm concentration. The listing is primarily a manufacturer-facing requirement, not a consumer-facing database or universal ingredient-label change. You can ask a brand or salon whether a product contains TPHP and whether it has been reformulated, but an ingredient declaration alone may not answer the concentration question.

The EU Rule Is a Separate, Phased Prohibition

Commission Regulation (EU) 2026/909 adds Triphenyl Phosphate (CAS 115-86-6) to Annex II of the EU Cosmetics Regulation. Products containing TPHP that do not comply with the restrictions may not be placed on the EU market from January 1, 2027; from July 1, 2028, they may no longer be made available on that market. Those dates distinguish first placement from later supply, and they mean the transition is still underway as of October 2026. [3]

Unlike California’s manufacturer process, the EU regulation phases in restrictions on placement and supply. Neither measure means “all nail polish is banned”; the applicable requirements depend on the product and market. [1][2][3]

TPHP Is Not TPO

The abbreviations are easy to mix up. TPHP means triphenyl phosphate. TPO means trimethylbenzoyl diphenylphosphine oxide, a separate substance associated with some UV-cured nail products. They are not alternate names for the same ingredient, and a regulatory update about one should not be applied to the other.

The European Commission says TPO has been prohibited in EU cosmetics since September 1, 2025, with no sell-through or professional-use exception under its guidance. TPHP’s EU measure is the distinct 2026 regulation with the January 2027 and July 2028 transition dates above. So a “TPO-free” claim does not tell you whether a polish contains TPHP, and the California TPHP listing does not concern TPO. [3][4]

What the Nail Polish Exposure Study Found—and Did Not Find

A 2016 study tested ten nail polishes purchased in 2013–2014. Eight contained TPHP, at concentrations up to 1.68%; two products containing it did not list TPHP on the label. In a small group of 26 participants, researchers observed that urinary diphenyl phosphate (DPHP), a metabolite used as an exposure marker, rose to nearly seven times the pre-application level 10–14 hours after application of a polish containing 0.97% TPHP. A separate glove comparison involving ten participants found lower DPHP after application with gloves, consistent with uptake through skin. [5]

These results are evidence that TPHP exposure from polish was measurable in that study. They are not a test of current products, do not show that every polish contains TPHP, and do not demonstrate that participants developed a health condition. The small sample and older product set also limit how broadly the results can be generalized. Urinary biomarker changes indicate exposure; they are not, by themselves, a diagnosis or proof of harm.

The EU’s decision is a regulatory action, not a clinical finding about an individual bottle. For shoppers, it is more useful to keep three things distinct: whether a product contains TPHP, how much it contains, and what a particular rule requires in a particular market.

Practical Steps When Buying or Using Nail Products

• Read the ingredient list and look for “triphenyl phosphate” or “TPHP,” while remembering that a label does not usually show a concentration in ppm.
• If you use a salon product, ask the salon or manufacturer about the ingredient and whether the formula has changed. Do not assume a product is TPHP-free just because it is described as “clean,” “non-toxic,” or “TPO-free.”
• Follow the product’s directions and warnings, keep it away from children, and use nail products in a well-ventilated area. The U.S. Food and Drug Administration also advises reading labels carefully and reporting reactions to FDA. These are general nail-product precautions, not TPHP-specific instructions. [6]
• If you shop in the EU, note the 2027 and 2028 TPHP transition dates; if you shop in California, remember that the state listing’s 250 ppm threshold is not typically visible on a retail label.

If you are comparing several products, Toxic Scan can help you read ingredient labels and understand what a name refers to. It cannot determine a product’s laboratory-measured concentration from a photo or replace official regulatory information. For context on related consumer topics, see our guides to EU fragrance-allergen labels, aluminum in deodorant, and identifying chemicals in everyday products.

What to Take Away

California’s TPHP listing is a manufacturer compliance trigger, not a consumer discard notice. The EU has a separate phased rule, and TPHP and TPO are different chemicals. Ingredient awareness can help you ask useful questions, but a label or marketing claim alone does not reveal a product’s precise concentration.

References

1. California Department of Toxic Substances Control. (2026). “Safer Consumer Products: Listing Nail Products Containing Triphenyl Phosphate (TPhP) at Concentrations Greater Than 250 Parts per Million (ppm) as a Priority Product.” CEQAnet, SCH No. 2026060214. https://ceqanet.lci.ca.gov/2026060214
2. California Office of Administrative Law. (2026). “October 1, 2026 Effective Date.” https://oal.ca.gov/october-1-2026-effective-date/
3. European Commission. (2026). “Commission Regulation (EU) 2026/909 of 27 April 2026.” Official Journal of the European Union. https://eur-lex.europa.eu/eli/reg/2026/909/oj/eng
4. European Commission. (2025). “TPO in Nail Products – Questions & Answers.” https://single-market-economy.ec.europa.eu/sectors/cosmetics/tpo-nail-products-questions-answers_en
5. Mendelsohn, E., Hagopian, A., Hoffman, K., Butt, C. M., Lorenzo, A., Congleton, J., Webster, T. F., & Stapleton, H. M. (2016). “Nail Polish as a Source of Exposure to Triphenyl Phosphate.” Environment International, 86, 45–51. https://pubmed.ncbi.nlm.nih.gov/26485058/
6. U.S. Food and Drug Administration. (n.d.). “Nail Care Products.” Retrieved October 12, 2026, from https://www.fda.gov/cosmetics/cosmetic-products/nail-care-products