Liquid concentrate for the preservation of cosmetic and pharmaceutical products

The invention relates to a liquid concentrate for the preservation of cosmetic and pharmaceutical products which comprises 3-iodo-2-propynyl butylcarbamate (IPBC), at least one liquid carrier selected from the group consisting of: polyvalent alcohols, glycol esters and glycol ethers, and at least one stabilizer selected from the group consisting of: formic acid, formic acid salts, and formate esters, and comprising no additional carboxylic acid selected from the group consisting of: benzoic acid, propionic acid, salicylic acid, sorbic acid, 4-hydroxybenzoic acid, dehydroacetic acid and 10-undecylenic acid and a salt thereof being present.