CUPERTINO (CBS / AP) — Apple is banning the use of two potentially hazardous chemicals during in the final assembly of iPhones and iPads as part of the company’s latest commitment to protect factory workers who build its trendy devices.

The decision announced Wednesday comes five months after the activist groups China Labor Watch and Green America launched a petition drive calling on Apple Inc. to abandon the use of benzene and n-hexane in the production of iPhones.

READ MORE: Two Men Fatally Shot Near Laurel District in Oakland

Apple says a four-month investigation at 22 factories found no evidence that benzene and n-hexane was endangering the roughly 500,000 people who work at the plants.

READ MORE: Afghan American Family Finally Returns to California; 'It's A Story Of Hope'

The Cupertino-based company nevertheless decided the substances should no longer be allowed during the final assembly process.

Benzene can cause leukemia and n-hexane has been linked to nerve damage.

MORE NEWS: Will The Oakland A's Strikeout With Fans Over Proposed 2021 Ticket Price Hikes?

© Copyright 2014 The Associated Press. All Rights Reserved. This material may not be published, broadcast, rewritten or redistributed.