This Standard covers physical requirements and test methods for performance pertaining to structure, water resistance, chemical/stain resistance, ignition testing, cleanability, and other significant properties, in addition to general requirements of materials, workmanship and finish of plastic water closet seats and covers. While this standard covers the performance requirements of plastic water closet seats and covers and describes those performance requirements in terms of methods of test applicable to all such units, a number of different materials and methods of manufacture shall be permitted to be used to meet the requirements.