This standard specifies the terms and definitions, principles, instruments, reagents, specimens, test procedures and test reports of the test method for the color fastness of Wood Plastic Composite composites to chlorine water. Applicable to polyethylene (PE) (PE) or polypropylene (PP) (PP) Wood Plastic Composite Composites. The referenced specification documents include GB/T 250, GB/T 6682, GB/T 7921, GB/T 8433-2013, GB/T 19106-2013 and JC/T 2222. The principle of the test is to soak the Wood Plastic Composite composite sample in a solution with a given effective chlorine concentration, then dry it naturally and evaluate its discoloration. Required instruments include container, Electronic Balance, pH Meter, grey sample card and colorimeter for evaluating discoloration. The test water should meet the requirements of analytical pure reagents and GB/T 6682 standards.