On July 1, 2025, the European Commission's (EC) Scientific Committee on Consumer Safety (SCCS) issued a final opinion on hydroxyapatite (nano) in oral products. The EC asked SCCS if it considers hydroxyapatite (nano) safe when used in toothpaste up to a maximum concentration of 29.5 percent and in mouthwash up to a maximum concentration of ten percent according to the specifications as reported in the submission, taking into account reasonably foreseeable exposure conditions. According to the opinion, based on the data provided, SCCS considers hydroxyapatite (nano) safe when used at concentrations up to 29.5 percent in toothpaste, and up to ten percent in mouthwash. The opinion states that the available evidence "shows that hydroxyapatite (nano) does not pose a mutagenic hazard or cytotoxicity or inflammatory effects even when tested at high concentrations in a buccal mucosa cell model." The opinion notes that any uptake of hydroxyapatite (nano) by buccal mucosa "is considered negligible, and the epithelial cells with internalised particles will be shed out over time as they are continually replaced. Also, any unintentionally ingested [hydroxyapatite] nanoparticles during the use of oral-care products will undergo rapid dissolution in the gastric fluid and therefore do not raise any nano-specific concern over safety." SCCS's opinion applies only to hydroxyapatite (nano) that have the following characteristics:
- Composed of rod-shaped particles of which at least 87 percent (in particle number) have aspect ratios equal to or less than three, and the remaining 13 percent have aspect ratios not exceeding nine;
- The hydroxyapatite particles are not coated or surface modified; and
- The opinion is related to hydroxyapatite particles with max length of the hydroxyapatite nanoparticles in the present opinion, i.e., 122 ± 43 nanometers (nm).
The opinion is not applicable to any hydroxyapatite (nano) material that is composed of or contains needle-shaped particles.
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