A labour rights group said Thursday it had found "deplorable" conditions at Apple suppliers in China, following a probe of several firms that make the US technology giant's hugely popular products.
New York-based China Labor Watch said a four-month investigation of 10 suppliers to Apple in southern and eastern China uncovered violations of workers' rights, including excessive overtime and hazardous work conditions.
The 10 firms investigated included Foxconn, Jabil Circuit and BYD Electronic in the southern city of Shenzhen, as well as Riteng Computer Accessory and Kenseisha in the commercial hub Shanghai and five others in nearby Jiangsu province.
"This investigation of 10 different Apple factories in China finds that harmful, damaging work environments characterised by illegally long hours for low levels of pay are widespread in Apple's supply (chain)," the group said.
The report was based on surveys and interviews of 620 workers, as well as first-hand observations by a team of six, including some who entered the factories undercover.
The lengthy report followed findings announced in March by the Fair Labor Association (FLA), which toured three Chinese suppliers with Apple's consent and also reported on forced overtime and other problems.
China Labor Watch director Li Qiang urged Apple to make good on pledges to improve, and in a letter to the California-based company's chief executive Tim Cook called for immediate changes to be made.
"Are these promises sincere or merely a public relations ploy?" the report asked.
Speaking to AFP, Li said the FLA investigation had better access than his organisation, but that report blamed the suppliers instead of placing responsibility on Apple.
"Apple should take the responsibility to change the poor working conditions of those workers," Li said.
Following the FLA report, Apple's largest supplier, Taiwan's Foxconn, pledged to end workplace abuses at its factories in China, including overtime above the amount permitted by Chinese law.
Foxconn has come under scrutiny since 2010, following a spate of suicides and incidents of labour unrest at its Chinese plants.
At least 13 of its employees died in apparent suicides in 2010, with several more deaths last year.
China Labor Watch reported that other Apple suppliers had treated their staff worse than Foxconn, which has received the most attention.
"The labour rights violations at Foxconn also exist in virtually all other Apple supplier factories and in many cases are actually significantly more dire than Foxconn," the report said.
The group found employees worked an average of between 100 and 130 hours of overtime a month at the 10 factories, well above China's legal limit of 36 hours.
Low wages compelled workers to accept overtime and some factories did not properly compensate them for the hours, it said.
Working conditions in factories that produce cases for Apple products were especially poor, including exposure to loud noise and toxic chemicals, the report said.
Workers had little ability to push for better conditions because they did not know how independent unions functioned, it said. China only allows only one national trade union, which has links to the government.
Apple products are wildly popular in China, where the iPhone and iPad are particularly coveted by wealthy consumers.
China Labor Watch said more than 70 percent of the workers it surveyed did not own Apple products but would like to have at least one.
Apple and Foxconn did not respond immediately to requests from AFP for comment.