These requirements apply to clothes dryer transition ducts intended for venting household and commercial clothes dryers. The ducts covered by these requirements are intended to connect a clothes dryer to an existing permanent duct provided as a part of the building structure. The duct is intended to vent lint and humid air from drying clothes. A product that contains features@ characteristics@ components@ materials@ or systems new or different from those in use when the Outline of Investigation was developed@ and that involves a risk of fire@ electric shock@ or injury to persons@ shall be evaluated using the appropriate additional component and end-product requirements as determined necessary to maintain the level of safety for the user of the product as originally anticipated by the intent of this Outline of Investigation. A product whose features@ characteristics@ components@ materials@ or systems conflict with specific requirements or provisions of this Outline of Investigation cannot be judged to comply with this Outline of Investigation. Where considered appropriate@ revision of requirements may be proposed and adopted in conformance with the methods employed for development@ revision@ and implementation of this Outline of Investigation.