The sniff test is a technique for checking the efficacy (protection against armpit odour) of a deodorant. Subjects participating in this test must follow a precise protocol to ensure that no deodorants or antiperspirants used beforehand affect the results of this test. Employees who have had special training in this technique, the so-called “sniffers”, analyse the results of the test and assess the efficacy of the deodorant based on a standard scale. In order to achieve a direct comparison, the test subjects only ever apply the product under test to one armpit. Depending on the manufacturer’s preference, the length of use and analysis time can vary in order to be able to make claims for after 12h, 24h or 48h.