(a) Unicellular expanded polyvinyl chloride-acetate copolymer or synthetic rubber modified polyvinyl chloride, polymer or copolymer plastic foam shall be of three types as follows:
Type A - for life preservers, buoyant vests or buoyant cushions.
Type B - for buoyant vests or buoyant cushions.
Type C - for ring life buoys.
(b) [Reserved]