Workers charged with cleaning the touch screens of iPhones and other Apple products were poisoned by the chemical used, n-hexane. From the Guardian:
Prolonged over-exposure to n-hexane can cause extensive damage to the peripheral nervous system and ultimately the spinal cord, leading to muscular weakness and atrophy and even paralysis, said Paul Whitehead, a toxicology consultant and member of the UK’s Royal Society of Chemistry. It can also affect male fertility. Recovery can take a year or more.
The chemical’s potential risks are well-known in industry, as are safe exposure limits. But the Wintek manager who decided to switch from alcohol to n-hexane for cleaning – apparently because it dried more quickly – did not assess the dangers. It was used without proper ventilation.
…Asked if they knew what products they were working on, three of the affected Wintek employees said team leaders told them they were working for Apple. They instantly recognised pictures of an iPhone and said they were cleaning touch screens, adding that items for other brands were not affected because Apple had isolated its production line. A lawyer acting for 44 of the poisoning victims also said several had named Apple.
Wintek, which does not discuss its clients, said it had replaced the factory’s general manager.