Green America and China Labor Watch launched their campaign Wednesday to protect the health of factory workers assembling the devices in China. The groups unveiled an online petition protesting the use of benzene and n-hexane in the production of iPhones.
Benzene is a carcinogen that can cause leukemia if not handled properly and n-hexane has been linked to nerve damage.
"Apple is a highly popular brand, one that consumers trust and expect to act responsibly," said Elizabeth O'Connell, campaigns director at Green America, in a statement. "Apple is also highly profitable, so it can easily afford to do right by its workers and make the necessary changes to appeal to its socially-conscious consumers."
Apple says it has already removed a long list of toxic chemicals and ensures all remaining toxic substances comply with U.S. safety standards.
The protesting groups contend that it would cost Apple less than $1 per iPhone to come up with a safer manufacturing recipe.
Apple has long drawn fire for its labor practices in China, where contract manufacturing giant Foxconn assembles the company's iPhones. In 2013, China Labor Watch said that problems were rife across Apple's supply entire, including low worker wages, excessive hours and dangerous working conditions.
In a report this year on its suppliers' progress in improving their labor practices, Apple said it is working with firms to identify health hazards. The company also launched an education program in China to train health, safety and environmental personnel.