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Injuries, Illnesses, and Fatalities

Occupational Safety and Health Changes to OIICS, NAICS and SOC

In September 2010, the Bureau of Labor Statistics completed a major revision to the Occupational Injury and Illness Classification System (OIICS). The revised OIICS structure (OIICS 2.01) was used for reference years 2011 through 2022 for both the Census of Fatal Occupational Injuries (CFOI) and the Survey of Occupational Injuries and Illnesses (SOII). In 2022, the OIICS structure underwent another comprehensive revision (OIICS 3.01) for use beginning with reference year 2023. Each of these OIICS revisions resulted in series breaks for both the CFOI and SOII programs for the noted reference years. As a result of these series breaks, new series IDs were created for OIICS characteristics available in the public IIF databases ( for both CFOI and SOII. For more information on OIICS versions and changes, see:

The Standard Occupational Classification (SOC) system is used to classify occupations for both CFOI and SOII. Beginning with the 2019 reference year, CFOI and SOII began using the 2018 SOC system for coding occupations. The SOC 2010 system was used for reference years 2011 through 2018.The SOC 2000 system was used for reference years 2003 through 2010. While the changes to the new structures (SOC 2010 and 2018) were not extensive, comparisons of SOC 2000, SOC 2010, and SOC 2018 occupations should be made with caution. More information on the SOC coding versions used in CFOI and SOII can be found here:

The North American Industry Classification System (NAICS) is used to classify industry for both CFOI and SOII. NAICS is revised on a 5-year cycle to reflect changes in the economy, resulting in new standards for 2007, 2012 and 2017. These changes were incorporated into SOII and CFOI industry data 2 years later, for 2009, 2014 and 2019 respectively. These changes resulted in a series break for SOII industry data from 2013 to 2014, and footnotes should be consulted to check for incompatibility in other cases. For additional information regarding differences between NAICS 2002, NAICS 2007, NAICS 2012, and NAICS 2017 visit the U.S. Census Bureau NAICS webpage.

For more information on changes in coding structures and the years to which they apply, see the IIF Timeline of Key Developments in our Handbook of Methods


Last Modified Date: November 8, 2023