4.1 Resilient floor covering is made by fusing polymer materials under heat or pressure, or both, in various manufacturing and decorating processes. The polymer material may be compounded with plasticizers, stabilizers, fillers, and other ingredients for processability and product performance characteristics. The formulation of the compound can be varied considerably depending on the desired performance characteristics and methods of processing.

4.2 Light stability, which is resistance to discoloration from light, is a basic requirement for functional use.

4.3 This test method provides a means of measuring the amount of color change in flooring products when subjected to accelerated light exposure over a period of time (functional use of the flooring product).

4.4 This test method specifies that a sample is measured by a spectrophotometer and expressed in δE* units before and after accelerated light exposure.

Note 2: It is the intent that this test method be used for testing light stability performance properties to be referenced in resilient flooring specifications.