Market Recycles its Foam-styrene Cartons

Each work day at the Tokyo Central Wholesale Market in Tsukiji, Chuo Ward, as the time nears 7 a.m. mounds of discard foam-styrene containers measuring four or five meters high appear.

They are part of about 90 tons of waste, including expanded styrene and organic waste, discarded daily. Up to 50% of the waste from the market consists of used paper, cardboard boxes, and foam-styrene containers. The mass of the last category alone averages 13 tons. However, the entire leavings gets recycled.

The annual total of foam-styrene waste at the market expanded from 575 tons in 1976 to 3496 tons in 1997. How to handle the increasing volume became a major concern, according to Toshihiro Ono, managing director of the Tsukiji Market Association. He is charged with processing the waste.

The association's original disposal method was to burn it, or crush it with bulldozers and transport it to landfills along Tokyo Bay. However, burning the foam generated an enormous volume of acrid smoke, drawing complaints from those working in the market. The association since 1977 has been melting it.

Today, all used foam-styrene containers are heat-treated at a processing facility and compressed into blocks weighing seven to 10 kilograms each. The blocks are exported to processing plants in China. Foreign matter, including fish scales and adhesive tape, is removed, and the foam is transformed into granules about five millimeters in diameter.

The granules are then sold to manufacturers in China and Southeast Asia, which process them into such products as videotapes, clothes hangers, flowerpots, and combs. Japan then imports the final products.

The previous case study was adapted from a story produced for the Feb 8 edition of Yomiuri Shimbun.