Jan. 26 (Bloomberg) -- An accident at a chemical plant in Wuelfrath, northwest Germany, injured nine people today.

A chemical derived from zinc acetate mixed with air and formed a cloud at about 7.30 a.m., injuring workers from companies adjacent to a plant operated by ASK Chemicals GmbH, Reinhard Schneider, a spokesman for the town of Wuelfrath, said by telephone.

The cloud has since dispersed and the air around the site is being tested to determine whether there is still a potential health hazard, Schneider said.

ASK Chemicals is a joint venture of Sued-Chemie AG, based in Munich, and Ashland Inc. based in Covington, Kentucky. The company has 1,600 employees, about 250 of whom work at the Wuelfrath plant, according to its website.

ASK spokesman Ulrich Girrbach wasn’t immediately available for comment.

--Editors: Alan Purkiss, Tim Farrand

To contact the reporter on this story: Richard Weiss in Frankfurt at rweiss5@bloomberg.net

To contact the editor responsible for this story: Benedikt Kammel at bkammel@bloomberg.net