Process hazard analysis (PHA) identifies existing risk reduction measures so that their contribution to reducing risk can be determined in order to decide if the risk of hazard scenarios is tolerable. Unfortunately, PHA practitioners do not follow consistent practices in crediting risk reduction measures as there are no generally accepted standards or guidelines for doing so. This situation leads to inconsistent studies and possibly erroneous results. The meaning of risk reduction measures and their relationship to process safeguards are discussed in this article, and risk reduction measures that could be credited in PHA are identified. © 2012 American Institute of Chemical Engineers Process Saf Prog, 2012.