Determination of PAO
Determination of PAO (Period After Openng) for a cosmetic product is a very difficult task, as, beside the varibility of the cosmetic formulation, it depends on several factors that are not easily framed, such as the product presentation (packaging and volume), the mode of using etc.
Therefore COMPLIFE service for PAO evaluation has to be interpreted as a consultancy/collaboration for the Customer that integrate the laboratory testing.PAO evaluation is applied to new cosmetic products.
The main test is a microbiological assay, the In-Use Test, supplemented – if necessary – by chemical-physical determination or Dermatological Tests. For PAO evaluation, samples are usually preincubated in controlled conditions of temperature and humidity, then evaluated; such conditioning period could is predictive of ageing of the cosmetic product, then samples are distributed to volunteers for using, carrying out periodical microbiological tests, with a frequency that is related to the specific characteristc of the cosmetic product.”
