This is a test method for determining values of flame propagation distance and optical smoke density for plastic sprinkler pipe that is to be installed in ducts, plenums, and other spaces used for environmental air. This test method does not cover the construction requirements for sprinkler pipe for pressure or other performance requirements. A product that contains features, characteristics, components, materials, or systems new or different from those covered by the requirements in this standard, and that involves a risk of fire or of electric shock or injury to persons shall be evaluated using appropriate additional component and end-product requirements to maintain the level of safety as originally anticipated by the intent of this standard. A product whose features, characteristics, components, materials, or systems conflict with specific requirements or provisions of this standard does not comply with this standard. Revision of requirements shall be proposed and adopted in conformance with the methods employed for development, revision, and implementation of this standard.