What is the explanation for the abbreviation R-EP90 cable insulation type?

The abbreviation R-EP90 for cable insulation type refers to a specific classification of rubber insulation designed to withstand elevated temperatures, with "R" indicating rubber and "EP" denoting its ethylene-propylene composition. The "90" signifies that the insulation can operate at temperatures up to 90 degrees Celsius. This type of insulation is commonly used in various electrical applications due to its durability, flexibility, and resistance to environmental factors.