SPF Testing for Sunscreens: Tests Scope, Methodology & Standards Compliance

1. In vivo SPF Test – This test determines the Sun Protection Factor (SPF) of a product by assessing its effectiveness in preventing UVB-induced erythema on human skin. It is conducted under controlled conditions according to international standards such as ISO 24444.
2. In vivo UVA Test – PPD (Persistent Pigment Darkening) – The PPD method measures the UVA protection level of a sunscreen based on the skin’s pigment darkening response after UVA exposure. It is widely used in regulatory frameworks such as the European Commission’s guidelines, ISO 24442
3. In vitro UVA-PF Test – This test evaluates the UVA Protection Factor (UVA-PF) by measuring the absorbance of UV radiation through a sunscreen-applied substrate. It is performed in compliance with ISO 24443 and does not require human testing.
4. Broad Spectrum Protection (In Vitro) – The test verifies that a product offers balanced protection against both UVA and UVB radiation. It is typically conducted using in vitro spectral absorbance analysis, meeting FDA or ISO broad-spectrum criteria.
5. Water Resistance Test (ISO or on the basis of FDA Guidelines) – This test assesses the product’s ability to maintain its SPF after water immersion, simulating real-life water exposure. It is carried out in accordance with either ISO 16217/18861 or FDA water resistance protocols (40 or 80 minutes).
6. Sweat Resistance / High Sweat Resistance (In Vivo) – The test measures a product’s efficacy in maintaining UV protection during and after exposure to sweating conditions. It is performed on human volunteers under controlled environmental conditions to simulate high perspiration.
7. ANTI-SAND Test (Sand Resistance for SPF) – This test evaluates the product’s ability to resist sand adhesion and maintain its SPF after contact with sand. It simulates real-world beach conditions to assess product performance in sandy environments.
8. Phototoxicity Test (In Vivo) – This test determines whether a product induces toxic skin reactions when exposed to sunlight. It involves applying the product to human skin followed by controlled UV exposure.
9. Photoallergenicity Test (In Vivo) – The test assesses the potential of a product to trigger allergic skin reactions upon exposure to UV radiation. It is performed on human subjects using a photo-patch testing protocol.

Turnaround Times:

• in vivo SPF test – results up to 10 days
• in vitro UVA test – results in 10 days