Summary Lockout reduces the risks posed by maintenance, repair and unjamming work on industrial machines. The CSST recently indicated that 5,225 accidents, six of which are fatal, still occur annually during the execution of such work on machines that are improperly or not locked out. Canadian standard CSA Z460-05 defines lockout as the placement, in accordance with an established procedure, of a lock or tag on a machine’s energy-isolating device in order to indicate that it must not be operated until the lock or tag is removed. According to the Regulation respecting occupational health and safety, workers who perform maintenance, repair or unjamming tasks in the danger zone of one of these machines must apply this process. This report shows that publications give different meanings or definitions to lockout, that the legal requirements on this subject vary by Canadian province and by country, that there are normative differences in this respect, that the lockout programs in books and guides differ, and finally, that Québec establishments have programs with regulatory or normative deficiencies. This study, which will help companies wanting to draw up or carry out a lockout program be better equipped, will open the way to subsequent research on the application of lockout in industry.Following this project, a technical fact sheet was developed to provide companies with a simple and practical means of verifying the content of their lockout programs.