SHANGHAI: The number of workers poisoned by a toxic chemical at a Taiwanese factory in Jiangsu province has increased from 47 to 62, more than a month after angry employees attacked the company over management and pay disputes.

Workers from United Win Technology, which is owned by the Taiwan-based Wintek Corporation that produces iPad components for Apple, have suffered from muscular atrophy and damage to their nervous systems since August 2008 after they used n-hexane as a cleaning agent for touch panels produced at the Suzhou factory.

They complained they had not been given safety instructions, nor warned of the dangers of the chemical, and had worked in poorly ventilated rooms for long hours.