Methods for water resistance testing of sun protection products

Publisher Website
Google Scholar
Abstract
Synopsis Water resistance of sun protection products has been found to be best determined by the following methods: (1) Tests for determining UVL filter adherence to merino wool; this gives a rough value for orientation. Values in excess of 6% are suggestive of satisfactory adherence. (2) Tests for determining water resistance of sunscreen products on pig skin constitute a further essential step. Values in excess of 50% provide a realistic basis for tests in humans. In addition to filter adherence the product base, i.e. primarily the emulsifiers, are of special significance. Adequate results can be obtained with both W/O and O/W systems. Tests on volunteers are best done at the time of determining the sun protection factor, i.e. when simulating the events during a 2-3 h sunbath. Simulation should involve a single application of the test product in a pre-defined quantity and all activities conmmonly done in sunlight, e.g. swimming, as well as intermittent exercises to induce sweating. Values are considered as excellent, if 1 MED is not exceeded after 3 h exposure. Sun protection products with this characteristic qualify as adequate 'all-day' sunscreen for individuals with average sensitivity.

This publication has 0 references indexed in Scilit: