Chloroprene rubber (CR) is more commonly know by the trade name Neoprene®.
Chloroprene is unusual in that it is moderately resistant to both petroleum oils and weather (ozone, sunlight, oxygen). This qualifies Neoprene® for O-ring service where many other elastomers would not be satisfactory. It is also used extensively for sealing refrigeration fluids. FDA grades are available. Neoprene® has good compression set characteristics, abrasion resistance, and a temperature range of -65° to 285°F (-55° to 140°C).
PAI offers Neoprene® compounds in a hardness range of 40 to 90 durometer. Black is the standard color, but many other colors are available.