The ASTM D1148-2018 standard is used to evaluate the discoloration of white or light-colored vulcanized rubber under high humidity, high temperature, and UV conditions. The method simulates UV or UV/visible light exposure in a controlled environment to determine the color change of the rubber surface. These test results help producers and consumers understand how the material is likely to perform in actual use, although they are not directly equivalent to the results of natural exposure. The standard also includes a qualitative assessment of the degree of discoloration and is distinguished from staining tests. The SI units used in the test are standard units.