Apple has posted an extensive guide [PDF] to how Apple and its suppliers are operating together. The progress report contains many details of audits that Apple has done across 127 facilities that produce Apple products.
Apple is committed to driving the highest standards of social responsibility throughout our supply base. 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.
The report covers all suppliers and issues in great detail but there a couple of incidents of note, the first is the suicides that plagued the Foxconn facility in Shenzhen last year. To help resolve the issue Apple details the great lengths the company and Foxconn went to including conducting "an international search for the most knowledgeable suicide prevention specialists".
Secondly, Apple also addressed the use of N-Hexane in some of its partners facilities which caused 137 workers at a Wintek plant to fall ill after exposure.