PURPOSE: To provide the titled compsn. in which the emission of smoke during combustion is reduced without detriment to flame retardance, physical properties and processability inherent to the vinyl chloride resin, by blending specified quantities of antimony trioxide and an iron compd.

CONSTITUTION: 1W30pts.wt. antimony trioxide such as Thermoguards S (a product of M & T Chemicals), 2W20pts.wt. iron oxide and/or iron phosphate (having an average particle size of pref. 40μ or below) and 15W100pts.wt. plasticizer such as a trimellitate are blended with 100pts.wt. polyvinyl chloride resin.