Bactericidal antibiotics kill bacteria; bacteriostatic antibiotics slow their growth or reproduction. Hence the sulfonamide antibacterials exhibit a bacteriostatic rather than bactericidal effect. In general, combinations of a bacteriostatic antibiotic and bactericidal antibiotic are antagonistic. Prophylactics should be bactericidal rather than bacteriostatic. The highest division between antibiotics is bactericidal and bacteriostatic. Depending on their concentration, they act as bacteriostatic or bactericidal agents. Solutions are bacteriostatic or bactericidal according to their concentration. In contrast to many conventional antibiotics these peptides appear to be bactericidal instead of bacteriostatic. Glycerol is bacteriostatic in its action, and ethanol is bactericidal in its action. Salicylic acid is used as a food preservative, a bactericidal and an antiseptic. Aminoglycosides in lab tests showed some bactericidal activity. All disinfectants kill bacteria (called bactericidal). However, the concentration required for bactericidal activity is also highly dependent on bacterial concentration. When magnesium acetate is mixed with hydrogen peroxide it acts as a bactericidal. As a derivative of salicylic acid, bismuth subsalicylate displays anti-inflammatory and bactericidal action.