(Co)polycarbonates stabilised against .gamma.-radiation

A method of making a polycarbonate moulding composition resistant to high energy .beta.,.gamma.-radiation, which comprises adding to a polycarbonate from 0.01% by weight to 2.5% by weight, based on weight of polycarbonate, of a stabilizer of formula (I) ##STR4## wherein R.sub.1 and R.sub.2 represent, independently of each other, H, C.sub.1 -C.sub.36 alkyl groups which are optionally branched, C.sub.7 -C.sub.18 alkylaryl radicals or aralkyl radicals which are optionally branched and/or substituted, or C.sub.6 -C.sub.18 aryl radicals which are optionally substituted, or where two R.sub.1 -R.sub.2 radicals represent an aromatic ring which is incorporated by condensation and which is optionally substituted, and where R.sub.3 has the meanings given for R.sub.1,

• or of a stablizer of the formula (Ia) ##STR5## wherein R.sub.3 is defined as above for formula (I), and exposing the molding compound to .beta.,.gamma.-radiation.