Antimicrobials and Disinfectants

Preservatives combine both antimicrobials and antioxidants and are often added to water-containing products such as skin care ointments. In general, contact allergy to preservatives is considered rare. Sensitization to preservatives is often due to the use of products on damaged skin, e.g., eczema or leg ulcers. Patients often present with symptoms of dermatitis of the hands or face. The most frequently used preservatives in cosmetics and topical drugs are parabens, imidazolinidyl urea, quaternium-15, dimethylol-dimethyl (DMDM) hydantoin, phenoxyethanol, met-hylchloroisothiazolinone/methylisothiazolinone, dia-zolinidyl urea, 2-bromo-2-nitropropane-i,3-diol and sorbic acid (Schnuch et al. 1998). Preservatives and antimicrobials are also used in industrial products (called biocides), such as metalwork fluids.