SUQIAN, CHINA — Workers at an Apple iPhone suppliers' factory in Suqian, China are exposed to toxic substances, according to an investigation.

The report by New York-based China Labour Watch has criticised Chinese factory employees working at Apple supplier Catcher Technology work 10 hour days, six days per week.

The report also claims that the workers face exposure to toxic substances. It claims some workers hands aren't adequately protected by the provided gloves and that protective ear plugs and eye wear are not always available.

China Labour Watch says that some employees' eyes have experienced vision issues from cutting fluid and that noise in the factory can cause irreversible hearing damage.

The report also claims the factory's wastewater was directly dispensed into the public sewage system. Analysis of this found that it exceeded local standards for water quality.

In May last year, the report says 90 were sent to hospital following a chemical leak at the plant, and that five were in intensive care as a result. Investigation of the incident by the Administrative Committee of the Suzhou-Suqian Industrial Park said the cause was a mechanical failure, notes the report.

Apple told the Guardian it investigated these claims, interviewed 150 factory workers and found no violations of it's code of conduct. The tech giant told the paper that workers were provided with protective equipment and that wastewater was treated appropriately.