Apple has banned the use of two chemicals used in the final stages of manufacturing, following an investigation at 22 of its factories and amid claims that they cause health problems.
For some time activist groups have campaigned for the removal of benzene and n-hexane, which manufacturers use as a cleaning and solvent agent, from the workplace.
Back in March, Green America and China Labor Watch began pressuring Apple to stop using the chemicals, in favour of less hazardous alternatives. According to the Associated Press, Apple's own investigation launched soon after at 22 factories.
The firm found that 18 of the sites were not using the substances, while the other four were within agreed safety limits. Despite this, the company has decided to ban the two chemicals in the final stages of assembly for iOS devices and Macs, although they can still be used earlier on in the manufacturing process.
Apple's vice president of environmental initiatives Lisa Jackson said that the firm was doing all that it could to crack down on chemical exposures.
"We think it's really important that we show some leadership and really look toward the future by trying to use greener chemistries," she added.
N-hexane, in particular, has previously caused issues for the company. Wintek, one of its manufacturing partners, had 137 employees hospitalised, with many of them threatening to sue the firm over its use of the chemical. While Apple recognised the incident in its 2011 Supplier Responsibility progress report, it did not ban the product outright.
Benzene, although identified as carcinogenic, is still a vital part of producing polystyrene and nylon fibres in other industries.