Abstract: Concentrates containing from 0.5% to 20% by weight of an alkali metal borohydride, balance essentially inert dry resinous polymer are added to plastics in amounts effective to reduce traces impurities and thereby result in improved heat and light stability.

Abstract: A solid composition comprising a homogeneous mixture of a solid thermoplastic resin and from 1 to 80 weight % of at least one microbiocide which is insoluble in water, is readily dispersible or soluble in the resin at temperatures sufficiently high to permit plastic manipulation of the resin and the dispersion or solution of the microbiocide is sustained indefinitely upon cooling to ambient temperature while the diffusivity of the microbiocide in the resin under such conditions becomes vanishingly small, retains its microbiocidal activity in the resin and does not degrade or react with the resin in which it is dispersed. This compositon provides a convenient non-toxic dosage form of the microbiocide which is subsequently mixed with a second thermoplastic resin at a concentration of about 0.5 to 15 weight % to obtain a homogeneous resin composition containing an effective amount of the microbiocide.

Abstract: A microbiocidal solution for resin compositions including a glycyl phosphite or glycyl phosphonate and at least about 20 weight percent of a microbiologically active phenoxarsine. The composition can include additional solvents or dispersants or resin plasticizers.