of the unsaturated polyester resins. The production of PVC entails the production of "vinyl chloride resins", which differ in the degree of polymerization. Silicone resins Silicone resins are silicone-based polymers that exhibit various useful properties like weatherability (durability), dielectricity, water repellency, thermal stability, and chemical inertness. Health hazards Health hazards potentially associated with synthetic resins are typically less of a concern than the hazards associated with the cured products, which are more commonly in contact with consumers. Issues of interest include the effects of unconsumed monomers, oligomers, and solvent carriers. Dental restorative materials based on bis-GMA-containing resins can break down into or be contaminated with the related compound bisphenol A, a potential endocrine disruptor. However, no negative health effects of bis-GMA use in dental resins have been found. See also Prepolymer Resin casting Waterborne resins References Plastics Polymers