Last checked: October 2026. Written by Clockwork, which makes a toothpaste with 10% nanoXIM·CarePaste.
Nano-hydroxyapatite is assessed as safe in toothpaste only when the particles meet a precise specification. In the EU, that means rod-shaped, uncoated particles at no more than 10%. So the first question about any nHAp toothpaste is not "how much?" but "which material, made by whom, to what specification?" A percentage only means something once you know what it is a percentage of.
"10% protein" on a protein bar tells you little until you know which protein, from where and how pure. Nano-hydroxyapatite is the same. The name covers materials that differ in:
Two toothpastes can both print "nano-hydroxyapatite" and contain different materials. A bigger number for a material nobody has specified can't be checked, compared or traced.
The EU's Scientific Committee on Consumer Safety (SCCS) is the most detailed public safety review of nano-hydroxyapatite in oral care. Its history shows that the specification, not the name, is what gets assessed:
| Condition | Detail |
|---|---|
| Shape | Rod-shaped: at least 95.8% of particles with an aspect ratio (length ÷ width) below 3; the rest no more than 4.9 |
| Surface | Not coated or surface-modified |
| Amount | Up to 10% in toothpaste; up to 0.465% in mouthwash |
| Not covered | Needle-shaped particles; sprays or anything that could be inhaled |
Particle shape changes how a material behaves around cells. In a 2013 laboratory study on human airway cells, needle-shaped and plate-shaped nano-hydroxyapatite caused the most cell death, while rod-shaped particles did not raise toxicity even though cells took up more of them (Zhao et al., Archives of Toxicology). That is a lab finding, not a result in people. It helps explain why the EU's conditions specify rods, set an aspect-ratio limit and exclude anything that could be inhaled.
Shape, size, surface and purity are properties of a manufacturing process, so they come from a specific manufacturer. A named maker and a registration number let you trace the material:
Without these, "nano-hydroxyapatite" on a label is a word, not a specification.
Yes, once you know the material. In laboratory work by Fluidinova, the amount of nano-hydroxyapatite that settled on enamel rose with concentration. Amount matters. But a number for an unspecified material can't be compared with anything. Source first, then amount. A brand should be able to give you both: what the material is, and how much of the formula it makes up.
Clockwork Daily contains 10% nanoXIM·CarePaste. It is a named ingredient you can look up, not a generic description.
| Question | nanoXIM·CarePaste |
|---|---|
| What it is | Nano-hydroxyapatite made for oral care, supplied as a water-based paste |
| Who makes it | Fluidinova, Portugal |
| Shape | Rod-shaped; 95.8% of particles at aspect ratio below 3 |
| Size | Under 100 nm; Fluidinova gives a typical rod as about 30 nm long and 15 nm wide |
| Registration | REACH 01-2119490075-38-0021 |
| Safety review | Reviewed by the SCCS in 2023 |
| In Clockwork Daily | 10% of the formula, alongside 10% xylitol. Fluoride free, SLS free. Made in India |
If a brand can't answer, ask why. The full checklist: 6 questions → · What brands sold in India publish → · The complete guide to nHAp →
The EU's safety committee concluded in 2023 that it is safe in toothpaste up to 10% and in mouthwash up to 0.465%, when the particles are rod-shaped and uncoated. Its conclusion does not cover needle-shaped particles or sprays.
No. Since 2024 it is permitted in toothpaste and mouthwash under the conditions above, and not in products that could be inhaled.
Not on its own. The EU's safety conclusion stops at 10% in toothpaste, and a percentage of an unspecified material can't be compared with anything. Know the material first, then compare amounts.
Toothpaste is regulated as a cosmetic in India under the Cosmetics Rules, 2020 and the standard IS 6356. We could not find an Indian rule that names nano-hydroxyapatite specifically, which is why the EU conditions are the most useful published benchmark.
We print the ingredient by name and amount: 10% nanoXIM·CarePaste, made by Fluidinova. Its specification is published by its maker, so you can check exactly what you're buying.