One of the most significant changes affecting work globally over the past 25 years has been the growth of more flexible or less-secure forms of work arrangements, now typically labeled precarious employment or contingent work. While the terms precarious employment and contingent work are often used interchangeably, the former term has a somewhat wider coverage. As the review of international research, this chapter demonstrates that there is now substantial if not compelling evidence that the growth of precarious employment poses a serious threat to the maintenance of Occupational Health and Safety (OHS) standards. For a number of reasons already identified, the epidemic of injury and illness related to contingent work arrangements and job insecurity is not apparent in official OHS statistics. There is now a large and rapidly growing body of research examining the health and safety effects of job insecurity and contingent work arrangements.