Manufacturing activities in the personal computer industry are organised in a complex global production network (GPN) led by a variety of branded global lead firms. Increasingly, considerations on environmental, health and safety governance have emerged as an important element to the management and co-ordination of these production networks by lead firms. Within the personal computer GPN, the printed circuit board (PCB) industry is commonly subcontracted by branded firms to suppliers located in developing countries such as Penang, Malaysia. The activities of PCB manufacturing and assembly involve the use of various hazardous chemicals that pose environmental health risks to workers. This research aims to understand how governance over environmental health is implemented in the GPN led by Hewlett Packard (HP) and in particular with lower tier suppliers in the printed circuit board industry in Penang, Malaysia. The main research question is: how are environmental health concerns managed by governance mechanisms in GPNs that involve the relocation of harmful manufacturing activities to developing countries? Governance mechanisms within the GPN include private standards and codes of conduct, which are supplemented by government regulation in the host country. Governance outcomes are shaped by relations between firms and non-firm actors such as government agencies, civil society organisations and trade unions. Therefore, a GPN analytical framework is utilised to understand more specifically how a variety of firm and non-firm actors and their relationships and power dynamics influence governance practices in the industry. Fieldwork for the research was conducted in 2008 and 2010 and consisted of semi-structured in-person and telephone interviews with thirty seven key actors in Malaysia, Western Europe, and the United States. Key informants included HP; first tier suppliers to HP and second tier suppliers located in Penang, Malaysia; global and Malaysian civil society organisations; an international federation of trade unions and Malaysian trade unions; Malaysian government agencies; and a politician, occupational health doctor and journalist in Penang. The findings from this research show that a combination of factors results in a weak scenario for governing environmental health risks of suppliers in Penang. These factors are resource constraints among suppliers; weak host country capacity and willingness to regulate; weak knowledge of environmental health risks by firms and regulatory agencies; and weak contestation by external stakeholders. Findings from the analysis also show the need to have differentiated views of power amongst different actor relationships in order to understand the complexity of GPN governance.