(AP) -- Apple is defending itself against a fresh barrage of criticism from Chinese environmental activists over alleged pollution by the manufacturers who make its iconic iPhones, iPads and other products.
In a report issued Wednesday, a group of nongovernmental organizations accused the technology giant of violating its own corporate responsibility standards by using suppliers it said its investigations found are violating the law and endangering public health by discharging heavy metals and other toxins.
Responding to the report, Apple said Thursday that it was committed to "driving the highest standards of social responsibility" in its supply chain.
"We require that our suppliers provide safe working conditions, treat workers with dignity and respect, and use environmentally responsible manufacturing processes wherever Apple products are made," it said.
In a letter to the Institute of Public and Environmental Affairs, the Beijing-based NGO that spearheaded the report, Apple said it took such concerns seriously but had found discrepancies in the document.
It also proposed a "private conference call" with the institute, which responded by asking that other sponsors of the report be included in any dialogue.
Policing supply chains is a headache for big brand name companies, given the countless scandals over labor, environmental, safety and quality problems brought on by outsourcing to myriad factories in China and elsewhere in the developing world.
The latest report explores in more detail findings of an earlier one that took Cupertino, California-based Apple and other big electronics makers to task for alleged violations of labor and environmental standards.
It says Apple is spreading pollution through its supply chain and names seven facilities owned by five separate suppliers for specific problems, mainly with disposal of hazardous materials such as copper, nickel and cyanide.
Staff at two of those factories near Shanghai, Kaedar Electronics and Unimicron (Kunshan), said their managers were not available to comment Thursday.
Toxic waste and noxious smells from factories are a fact of life for many living in the heavily populated Shanghai region, and often standards demanded by residents are much higher than those allowed for industries.
An official with the local government in Kunshan said that the situation had improved from several years ago with the installation of a wastewater treatment plant, and that the Kaedar factory was expected to move to another area by 2013.
"It's true that it smells here, but the level of pollution is actually better than national standards," said the official, who asked to be identified only by his surname, Wang. "But when the wind blows, the smell is just unavoidable," he said.
The report also named Taiwan-owned Foxconn, also known as Hon Hai Precision Industry Co., which assembles Apple's iPhones and iPads in enormous factories in several mainland locations.
It said Foxconn's factory in the northern Chinese city of Taiyuan was emitting irritating gases resulting from metals surface processing, and authorities responsible for treating hazardous waste from its massive facility in the southern boomtown of Shenzhen had discharged pollutants exceeding legal limits.
Another suspected Apple supplier, Ibiden Electronics (Beijing), a Japanese maker of printed wiring boards, was discharging several dozen tons a day of sludge containing hazardous chemicals, the report said.
In its own social responsibility report, Ibiden says it exercises "rigorous control" over chemicals and is seeking to reduce use of those that are toxic.
Apple's latest supplier responsibility report acknowledges weaknesses, especially in suppliers' handling of hazardous substances, air emissions and environmental permits and reporting. The company says it is addressing those issues in its audit process, and has made progress.
The company had audited 288 facilities as of December 2010. Because Apple does not publicize its suppliers, public information about specific manufacturers serving them is hard to come by.
Explore further: Apple details labor violations at its suppliers