ISO 24442 · In vivo
ISO 24442: in vivo UVA protection (PPD)
Determines the UVA protection factor on the skin of volunteers from the persistent pigment darkening (PPD) induced by UVA radiation, comparing protected and unprotected skin.
Advantages
Compared with in vitro ISO 24443 and HDRS ISO 23698
- UVA protection measured in vivo, on real skin
- For markets or clients that require an in vivo UVA method
Limitations
- Requires volunteers and induces pigmentation on small test areas
- Longer and more costly than in vitro ISO 24443
- Does not report the critical wavelength; HDRS gives SPF, UVA-PF and CW without pigmentation
Principle
Test areas on the back are exposed to increasing UVA doses with and without the product. The UVA-PF is the ratio between the minimal dose that produces persistent pigment darkening on protected skin and on unprotected skin.
EU context
In the EU, UVA protection is usually substantiated in vitro with ISO 24443; the in vivo PPD method is used when a client or market specifically requires an in vivo UVA value.
At ISD Research
We advise on whether an in vivo UVA value is needed for your target markets, or whether ISO 24443 or HDRS covers the claim faster and without pigmentation.
Frequently asked questions
ISO 24442 or ISO 24443?
Both give a UVA-PF. ISO 24443 is in vitro, faster and also gives the critical wavelength needed for the EU UVA logo; ISO 24442 is used when an in vivo value is specifically required.
References
- ISO 24442. Cosmetics, Sun protection test methods, In vivo determination of sunscreen UVA protection.
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.