Deadly Explosion At Japanese Polymer Plant Could Cause Diaper Shortage

The worldwide disposable diaper industry will reel for months in the aftermath of a deadly accident at a polymer plant in Japan. The plant is a major global producer of the superabsorbent acrylic polymer (SAP) used in disposable diapers.

The Sept. 29 explosion and fire occurred in an acrylic acid tank at a Nippon Shokubai SAP plant in Himeji, near Kobe. It killed a firefighter and injured 36 other emergency responders and plant workers.

Made primarily from polymerized acrylic acid, SAP is the key absorbent ingredient in disposable diapers. Shokubai is the world’s largest producer of the material; other companies that produce it include BASF and Evonik Industries.

Shokubai says it has discontinued operations at the Himeji plant while the company and government officials conduct an investigation. With a production capacity of 320,000 metric tons per year, the facility accounts for 20% of the world’s supply of SAP, according to a new report on the disposable diaper market by the consulting firm Global Industry Analysts.

The diaper industry will “witness significant shortfall in supply of SAP over the next few months,” the GIA report says, adding that the Asian diaper market will be hit hardest. Shokubai may be able to alleviate market shortages by boosting capacity at its other plants, the consultants add. Shokubai runs smaller SAP facilities in Belgium, China, and the U.S.

Other SAP suppliers say they will endeavor to increase supply. BASF will seek to ease the impact on the market by running all its plants worldwide at capacity, a BASF spokeswoman tells C&EN. Similarly, Jeff J. Davis, Evonik’s general manager for baby care, says the company is “stretching” its acrylic acid and SAP capacity to support the market.

The Shokubai explosion continues a series of deadly accidents in recent months for the Japanese chemical industry. An explosion at a Mitsui Chemicals plant in April killed one worker and worsened shortages in the chronically tight market for m-cresol. In November 2011, an explosion at a Tosoh facility killed one employee and idled one of Japan’s largest vinyl chloride facilities.