Pure deodorants fight against body odour without inhibiting sweat secretion. Protection can be achieved by covering the sweat smell in the armpit by fragrance or other ingredients like essential oils that impart scent to the deodorant formulation.
Another very effective mode of action is to include antimicrobial substances that combat gram-positive bacteria, to prevent decomposition of sweat into degradation products with unpleasant odour. By incorporating antimicrobial substances that work selectively against odour-causing bacteria without impacting natural skin flora, pure deodorants can be formulated that are very gentle to the skin. Frequently used deodorant actives are sensiva® SC 50 and sensidin® DO.
In many deodorants both mechanisms are combined. Pure deodorants are an excellent option for consumers who want to use gentle deodorants without influencing the evaporation of sweat.
Deodorants frequently claim 24 or 48 hours protection. Authorities require that efficacy claims of cosmetic products should be substantiated scientifically, i.e. Commission Regulation (EU) No 655/2013. The efficacy of deodorants is typically verified by a sniff test. A sniff test determines the smell-inhibiting effect of the test products by directly sniffing the armpits of test subjects. Specifically adapted test protocols can be applied because no detailed legal guidelines are obligatory.
The deodorant can be tested against benchmark, untreated area or placebo. At least 10 (optimally 20) volunteers enter a conditioning phase without using any product applied to the axilla except a defined wash lotion. In the test phase trained evaluators determine the individual baseline of odour after washing of each subject. Then the deodorant(s) are applied. Depending on the requirements the next evaluation is conducted 24, 48 hours or longer after application. The results are compared with initial baseline value and between left and right axilla. The test protocol can include more evaluation points or a longer application period.