The present disclosure is directed to a plasticizer, polymeric compositions containing the plasticizer, and conductors coated with the polymeric composition. The plasticizer includes (i) an epoxidized fatty acid methyl ester, (ii) an epoxidized natural oil, and (iii) an epoxidized tallate ester. Polymeric compositions containing a polymeric resin and the plasticizer exhibit a weight loss less than 50 mg/cm2 after exposure to 100° C. for seven days. Conductors coated with the polymeric composition (containing the plasticizer) pass the low temperature unwind test of UL719 and exhibit a weight loss less than 50 mg/cm2 after exposure to 100° C. for seven days.