Testing the Sun Protection Factor (SPF) of cosmetic products is crucial to ensure they provide the claimed level of UV protection.

There are two primary methods for SPF testing:

In Vivo Testing
In vivo testing is conducted on human volunteers. The product is applied to the skin, which is then exposed to UV light to determine the minimum erythema dose (MED)—the smallest dose that causes redness. The SPF is calculated by comparing the MED of protected skin (with sunscreen) to unprotected skin.

In Vitro Testing
In vitro testing, on the other hand, is a laboratory-based method that uses a substrate, such as a PMMA plate. The product is applied to the substrate, exposed to UV radiation, and the amount of UV light that passes through is measured. This transmittance data is then used to estimate the SPF value.

Regulatory considerations are essential for both methods. Testing must follow international guidelines, such as ISO 24444:2019 for in-vivo and ISO 24443:2012 for in vitro testing. Additionally, compliance with regulatory authorities’ requirements, like the FDA in the USA and the European Commission in the EU, is necessary for accurate labeling and marketing of the product. While in vivo testing is considered more accurate, in vitro testing serves as a useful preliminary or supplementary method. Both methods aim to ensure that cosmetic products provide effective sun protection, safeguarding consumers against harmful UV radiation.

Take the next steps

If you would like to know more about the services ADSL provides or speak to a member of our Clinical department, please call +44 (0) 1803 520 048 or book a free video consultation with us using the Get Started link below.

  • Efficacy of cosmetic products
  • Quality testing
  • Analytical services
  • SPF Testing
  • In Vivo Testing
  • In Vitro Testing
  • Consumer evaluations
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