Aqueous and non-aqueous based end-user compositions which (i) are selected from the group consisting of cosmetic products, toiletry products, personal care products, oral care products, skin care products, hair care products, household & cleaning products, soap and bath products, industrial and institutional cleaning products, disinfecting products, wound care, sanitary products, agricultural compositions, textile industries, coating industries and laundry products; and (ii) contain, in the range of from 0.01 wt. % to 5.0 wt. % of the total composition, - a synergistic preservative composition (a) being capable of providing broad spectrum antimicrobial activity and of inhibiting or killing Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Aspergillus brasiliensis, Candida albicans and/or Burkhodelia cepacia, and (b) comprising 0.1 wt. % to 99.9 wt. % of propylene carbonate and 0.1 wt. % to 99.9 wt. % of one or more organic compounds selected from the group consisting of hexanediol, octanediol and hexylglycerin, wherein the ratio of propylene carbonate to organic compounds is in the range of from 1:10 to 10:1. (i) are selected from the group consisting of cosmetic products, toiletry products, personal care products, oral care products, skin care products, hair care products, household & cleaning products, soap and bath products, industrial and institutional cleaning products, disinfecting products, wound care, sanitary products, agricultural compositions, textile industries, coating industries and laundry products; and (ii) contain, in the range of from 0.01 wt. % to 5.0 wt. % of the total composition, - a synergistic preservative composition (a) being capable of providing broad spectrum antimicrobial activity and of inhibiting or killing Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Aspergillus brasiliensis, Candida albicans and/or Burkhodelia cepacia, and (b) comprising 0.1 wt. % to 99.9 wt. % of propylene carbonate and 0.1 wt. % to 99.9 wt. % of one or more organic compounds selected from the group consisting of hexanediol, octanediol and hexylglycerin, wherein the ratio of propylene carbonate to organic compounds is in the range of from 1:10 to 10:1. - a synergistic preservative composition (a) being capable of providing broad spectrum antimicrobial activity and of inhibiting or killing Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Aspergillus brasiliensis, Candida albicans and/or Burkhodelia cepacia, and (b) comprising 0.1 wt. % to 99.9 wt. % of propylene carbonate and 0.1 wt. % to 99.9 wt. % of one or more organic compounds selected from the group consisting of hexanediol, octanediol and hexylglycerin, wherein the ratio of propylene carbonate to organic compounds is in the range of from 1:10 to 10:1. (a) being capable of providing broad spectrum antimicrobial activity and of inhibiting or killing Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Aspergillus brasiliensis, Candida albicans and/or Burkhodelia cepacia, and (b) comprising 0.1 wt. % to 99.9 wt. % of propylene carbonate and 0.1 wt. % to 99.9 wt. % of one or more organic compounds selected from the group consisting of hexanediol, octanediol and hexylglycerin, wherein the ratio of propylene carbonate to organic compounds is in the range of from 1:10 to 10:1.