In 1999, North West OHS released a study of confined space fatalities based on reports from the Occupational Safety and Health Administration (OSHA), National Institute of Occupational Safety Health (NIOSH) and the Mines Safety and Health Administration (MHSA) with a breakdown of their causes. Researchers believe that the following numbers are only a fraction of the fatal confined space accidents that actually occurred as many locations are not initially identified as confined spaces, OSHA reports did not include non-hazardous confined space fatalities in their studies prior to 1982, NIOSH still do not include non-hazardous confined space fatalities in their studies and many American states do not note the presence of confined spaces in fatality reports submitted to OSHA.
