1. A composition and the method for sustaining the biocidal activity of chlorinated polystyrene hydantoin beads.

2. Common ingredients likely to contaminate products with formaldehyde include quaternium- DMDM hydantoin, imidazolidinyl urea and diazolidinyl urea.

3. 16 Maternal teratogens that hae been reported in association with cleft lip and palate include alcohol, maternal phenylketonuria , hyperthermia, hydantoin, trimethadione, aminopterin,[www.Sentencedict.com] and methotrexate.

4. The invention is an agent for prevention and treatment of acute renal failure, which contains a hydantoin derivative represented by the general formula below as an active ingredient.

5. The electrolyte composition according to the invention comprises at least one silver ion source, a sulfonic acid and/or a sulfonic acid derivative, a wetting agent, and a hydantoin.