Marine-Grade Moisture-Resistant Polyethylene (HDPE) Sheets and Bars lor: See Table Maximum Temperature: 180° F Tensile Strength: 4, 100 psi (Poor) Impact Strength: 1. 1 ft. - lbs./in. (Poor) Hardness: Durometer 68D (Medium) For Use Outdoors: Yes Specifications Met: ASTM D4976, UL 94 HB