ISO 16217 · In vivo
Water resistance: ISO 16217 and ISO 18861
A standardised water immersion procedure (ISO 16217) combined with the in vivo SPF before and after immersion. The percentage of water resistance is calculated according to ISO 18861 to support “water resistant” and “very water resistant” claims.
Advantages
Context
- Supports “water resistant” and “very water resistant” claims
- Combined with the SPF determination in the same study
Limitations
- In vivo: requires volunteers and the ISO 24444 procedure
- Not yet covered by in vitro or hybrid methods (ISO 23675, ISO 23698)
Principle
The SPF is determined on the back of volunteers after controlled immersion periods in a whirlpool bath, following ISO 16217, and compared with the SPF without immersion. ISO 18861 defines how the percentage of water resistance is calculated and evaluated.
EU context
Water-resistance claims on the EU market rely on in vivo testing: neither Double Plate nor HDRS covers them yet.
At ISD Research
Our water-resistance room has an immersion whirlpool bath next to the in vivo SPF room, so immersion and SPF determination run in the same study. Results are usually delivered in 3–4 weeks.
Frequently asked questions
Which standards are used for water resistance?
ISO 16217 defines the water immersion procedure; ISO 18861 defines the calculation of the percentage of water resistance. Both are combined with the in vivo SPF of ISO 24444.
References
- ISO 16217:2020. Cosmetics, Sun protection test methods, Water immersion procedure for determining water resistance.
- ISO 18861:2020. Cosmetics, Sun protection test methods, Percentage of water resistance.
Indicative summary of the standard: it does not reproduce or replace it, nor the ISD Research SOP or the study protocol.
Other methods
Is this the right method for your product?
Tell us your product, claim and market. We will propose the method and option that fit.