The preservatives are used in cosmetic preparations to prevent rancidity. Cosmetics They contain substances that can go rancid and can lead to bacterial growth, so we use antimicrobial preservatives and antioxidants.
Together with the scents are substances that cause most allergies and irritations.
I antioxidant preservatives are designed to counteract rancidity. This begins with the breaking of a CH bond (carbon-hydrogen), which generates radicals, which start a chain reaction. Triglycerides containing unsaturated fat and are more subject to rancidity. Antioxidants work by blocking free radicals and preventing them from continuing the chain.
Most of them are phenols, stabilized by resonance.
These include: butylated hydroxytoluene (BHT), butylated (BHA) and vitamin E (tocopherol).
action of antioxidants is often enhanced by synergistic agents, such as ' EDTA ol' citric acid, which act as chelators of metal ions such as copper and iron catalysts of the process dell'irrancidimento.
The antimicrobial preservative instead serve to prevent the formation of bacteria or fungi. In practice, the pollution of the product, due to the use of water, air, workers, gas, etc.. These include the ' benzoic acid, l' salicylic acid, l ' cinnamic acid (acid derivatives), the phenoxyethanol, l' Phenethyl alcohol and parabens (derivatives of alcohols) . These are used as antifungal, in a mixture of several products.
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