Antimicrobial active compositions and substances comprising at least one, preferably two, unbranched (straight-chain) 1,2-alkanediols and preferably a further preservative and also to products containing such mixtures in an antimicrobially effective quantity. One example of an antimicrobial mixture comprises: (a) 1,2-hexanediol and 1,2-octanediol and also optionally 1,2-pentanediol and/or 1,2-decanediol and (b) one, two or more substances selected from the group consisting of potassium sorbate, parabens and iodopropynyl butylcarbamate (IPBC).