Four pig farms were studied to assess the barn workers’ exposure to hydrogen sulphide (H2S) while\u00a0pulling pit plugs and power-washing production rooms. Results indicated that plug pulling generated\u00a0high concentrations of H2S reaching 1,000 ppm in some cases. All the farms studied had plug pulling\u00a0events that exceeded limits defined by the Occupational and Safety Regulations of Saskatchewan. The\u00a0H2S released when a plug was pulled did not follow a predictable pattern over time and within the room\u00a0space. Power washing generated lower H2S concentrations than plug pulling but workers were exposed\u00a0for a longer time period. Based on this study, swine barn workers may be exposed to H2S concentrations\u00a0that exceed acceptable limits when pulling pit plugs and power-washing rooms. Personal monitors should\u00a0be provided to all barn workers and training and standard operating procedures are needed so workers can learn how to deal with routine operations and emergency situations when high H2S concentrations are\u00a0generated .<\/p>\n