For employees to endorse drug testing there needs to be evidence of real safety benefits. In order to achieve this, the efficacy of workplace testing needs to be examined and the features of 'good practice' workplace testing practices need to be identified. To examine these issues, the National Centre for Education and Training on Addiction (NCETA) undertook an investigation of the role of workplace drug testing in improving workplace safety. The investigation involved a critical review of relevant literature and identified the extent and nature of alcohol or drug related risk to workplace safety.