How to measure the sunscreen index of cosmetics?

If you want to test and evaluate the sunscreen effect of sunscreen cosmetics, there are generally two indicators, one is SPF value and the other is PFA value. You can't know the exact value yourself, so you have to go to a professional testing institution to evaluate and test the efficacy of cosmetics.

Specific operation: the subject takes the front position to irradiate the back, predicts the minimum ultraviolet radiation (MPPD value) of the subject's skin 24 hours before the test, and adjusts the ultraviolet radiation according to the prediction result to test the subject. Firstly, a normal skin area of not less than 30cm2 ~ 2 is selected on the back of the subject, and the subject or reference substance is evenly applied to the above area at a dose of (2.00 0.05) mg/cm2; Then, according to the requirements of the specification, the UVA radiation dose is selected and irradiated in three situations: ① the subject's skin is not coated with the subject; ② Application of reference substance; (3) coating the measured object. After 2 ~ 4 hours, observe the experimental results and record the MPPD values in three cases respectively.

Hangzhou Huazhuang Technology Co., Ltd. is still very strong in the cosmetics testing industry. We can scientifically and reasonably choose the evaluation method of cosmetic efficacy claims based on product classification, standardize the evaluation of cosmetic efficacy claims, and achieve the purpose of cosmetic efficacy claims evaluation. I hope my answer can help you.