The LCD outfit Wintek, which makes panels for Apple's iPads, has said that it has taken proper measures, including medical treatment for affected employees. The outfit has been sued by workers who became sick allegedly due to exposure to a poisonous chemical at its China factory.

More than 44 workers at its subsidiary, United Win (China), are planning legal actions against Wintek, claiming they were poisoned by a chemical, n-hexane, that they used to clean screens for the Apple iPhone.

Wintek said the China subsidiary has stopped using n-hexane. All affected workers have been examined and treated, and they are recovering and returning to work, Wintek said.

In January 2010, workers at United Win staged a protest believing that the company would deny them their annual bonuses. Wintek later said the row was resolved and the workers would get their money.

The case has highlighted claims that Apple has been boosting profits margins on its electronic gear.