Synergistic antimicrobial compositions containing 1-hydroxymethylpyrazole and a preservative

A method of controlling the growth of at least one microorganism selected from a bacterium, fungus, or a mixture thereof, in or on a material or medium susceptible to attack by the microorganism comprising the step of adding to the material or medium a composition comprising

• (a) a compound having the formula (I) ##STR4## where R and R' are independently selected from hydrogen and alkyl of 1 to 4 carbon atoms, R" is a moiety selected from the group consisting of (a) hydrogen, (b) a halogen atom selected from the group consisting of F, Cl, Br, and I, and (c) a nitro group, or the hydrochloride salt of said compound;
• and
• (b) at least one preservative selected from 2-bromo-2-nitropropane-1,3 diol;
• dimethylhydantoin;
• imidazdidinyl urea;
• diazolidinyl urea;
• or 1-(3-chloroallyl)-3,5,7-triaza-1-azoniaadamantane chloride;
• wherein said components (a) and (b) are present in a combined synergistically effective amount to control said growth.

A method for preventing spoilage of a material or medium caused by bacteria or fungi comprising the step of adding to a material or medium a composition comprising

• (a) a compound having the formula (I) ##STR5## where R and R' are independently selected from hydrogen and alkyl of 1 to 4 carbon atoms, R" is a moiety selected from the group consisting of (a) hydrogen, (b) a halogen atom selected from the group consisting of F, Cl, Br, and I, and (c) a nitro group, or the hydrochloride salt of said compound;
• and
• (b) at least one preservative selected from 2-bromo-2-nitropropane-1,3 diol;
• dimethylhydantoin;
• imidazdidinyl urea;
• diazolidinyl urea;
• or 1-(3-chloroallyl)-3,5,7-triaza-1-azoniaadamantane chloride;
• wherein said components (a) and (b) are present in a combined synergistically effective amount to prevent or mitigate said spoilage.