Polychlorinated naphthalene contamination of some recently manufactured industrial products and commercial goods in Japan.

A follow-up case study was performed after two incidents of recent illegal import and use in Japan both of technical PCNs mixture and contaminated with those compounds an industrial raw material. In case 1, above 18 tons of PCNs mixture, resembling Halowax 1001, which is a technical PCNs formulation, were imported from the United Kingdom. An illegally imported PCNs mixture was used for manufacture of a wide spectrum of industrial materials and commercial goods including sealants, putty, shock absorbing materials, adhesive materials, insulating materials and rubber belts. About 1.3 tons of PCNs contained in the Neoprene FB manufactured reached domestic market and 9.3 tons could reach other markets. In case 2, which became known in 2001, the Japanese company imported from Canada 54 tons of PCNs contaminated raw rubber material for industrial use. In weathering test (40 degrees C for up to 168 h) of the feral rubber coated sheets for rubber bands 98% of di- and 66% of tri-CNs vaporized. A loss rate of tetra-, penta-, and hexa-CN during initial 12 h of the weathering test ranged from approximately 10 to approximately 20%, while from 12 to 168 h remained negligible.