SCCS Opinion on Hydroxyapatite (nano), SCCS/1648/22

Overview

The SCCS final opinion on hydroxyapatite (nano) evaluates the safety of a notified nano-form hydroxyapatite material in oral cosmetic products. It is not a finished-product occurrence study, but it contains regulatory-context heavy-metal impurity data for the submitted hydroxyapatite nano paste ingredient and a safe-use envelope for toothpaste and mouthwash. The impurity values below should not be pooled as toothpaste or mouthwash product concentrations.

Key numbers

• Opinion identity: SCCS/1648/22, final opinion adopted during the SCCS plenary meeting on 21-22 March 2023; PDF ISSN 1831-4767; ISBN 978-92-68-19389-1; DOI 10.2875/102239.
• SCCS safe-use conclusion: based on data provided, hydroxyapatite (nano) is considered safe up to 10% in toothpaste and up to 0.465% in mouthwash.
• Scope limits: the conclusion applies only to rod-shaped particles where at least 95.8% by particle number have aspect ratio below 3, the remaining 4.2% have aspect ratio not exceeding 4.9, and particles are not coated or surface-modified.
• Exclusions: the opinion is not applicable to needle-shaped hydroxyapatite (nano) particles and is not applicable to sprayable products that could expose consumer lungs to nanoparticles by inhalation.
• Impurity specification: Table 2 reports Total Heavy Metals (as Pb) at < 20 ppm for the notified hydroxyapatite nano paste ingredient, citing Ph. Eur. 7th Ed. 2.4.8 Heavy metals.
• Table 3 heavy-metal/element impurity results for the notified hydroxyapatite nano paste ingredient are in mg/kg; the source table prints three result columns in source order:

• Other Table 3 elements not routed through HMI metal source metadata because no current metal slug exists for them: potassium 11, 9.9, 7.5 mg/kg; sodium 82, 86, 110 mg/kg; strontium 43, 44, 24 mg/kg.
• Solubility: the material is described as insoluble or practically insoluble in water, with solubility 0.0065 g/L at 20 deg C by EU method A.6 under GLP, and soluble at low pH.

Methods (brief)

This is an SCCS regulatory-science opinion under the EU Cosmetics Regulation nanomaterial framework, not a market survey. The Commission requested assessment of hydroxyapatite (nano) in oral cosmetic products after prior SCCS opinions could not exclude genotoxicity concerns. The opinion focuses on newly submitted genotoxicity data plus chemical/physical characterization inherited from SCCS/1624/20.

The extracted text omits the body of Tables 2 and 3 because the tables render as images in the PDF. The table values on this page were read from a rendered image of PDF page 9 (pdftoppm -f 9 -l 9 -png -r 220), and the surrounding text was cross-checked in /tmp/mfk_june8_sccs_hydroxyapatite_nano.txt.

Speciation: the source reports arsenic only as Arsenic (As), so this page treats it as total arsenic context (tAs). Nickel, lead, barium, iron, copper, magnesium, and manganese are elemental impurity measurements; the source does not report Cr(VI), inorganic arsenic, methylmercury, or total mercury.

Related evidence

• Toothpaste (Cat 2)
• Mouthwash/oral rinse
• Arsenic, Total
• Barium
• Lead
• Iron
• Copper
• Magnesium
• Manganese
• Nickel

Update history

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