Polyform Modeling compound
[Polyform Products, Illinois] A brand name for a plasticized polyvinyl chloride modeling compound. Polyform is identical in composition to "Sculpey", but is packaged for professional artists. Polyform feels like modeling clay but it does not shrink on baking. Sculpey is available in a wide variety of colors. Polyform contains about 15% di-(2-ethylhexyl) terephthalate (DOTP) plasticizer (prior to 1991, it contain DEHP which was a carcinogen). The uncured clay should not be placed on painted or varnished surfaces as the plasticizer will dissolve these materials. Additionally, Polyform may be affected by solvent based paints. Polyform precautions recommend baking temperatures below 130C (275F).
Polyvinyl chloride decomposes at 190C (375F) to form hydrogen chloride fumes.