From 2011 to 2018, 1,030 workers died from occupational injuries involving a confined space. The annual figures range from a low of 88 in 2012 to a high of 166 in 2017. These data are from the Bureau of Labor Statistics, Census of Fatal Occupational Injuries (CFOI).
Fatal work injuries
Confined spaces are based on guidelines from the Occupational Safety and Health Administration (OSHA). A confined space:
More information on confined spaces, including examples, can be found on the OSHA website. Some examples include, but are not limited to, storage bins, manholes, and grain silos. CFOI considers a workplace fatality to involve a confined space if an aspect of the fatal incident occurred in a confined space based on the documents and information available in each fatal work injury case. As documents in a fatal injury work injury case may vary, cases coded as not involving a confined space may include cases for which there is insufficient documentation or information to determine whether the incident involved a confined space.
Many different types of confined spaces are involved in occupational deaths. The following table shows the most common types of confined spaces for the 643 cases where those data are available1 as well as the most frequent event that led to the fatal injury.
|Type of confined space||Fatalities||Most frequent event|
Tank, bin, vat interiors
|205||Engulfment in other collapsing material (86)|
Silo, grain bin interiors
|107||Engulfment in other collapsing material (72)|
Septic tank or water tank interiors
|19||Falls to lower level (7)|
|10||Engulfment in other collapsing material (7)|
Oil storage tank interiors
|7||Inhalation of a harmful substance (4)|
Grain elevator interiors
|6||Engulfment in other collapsing material (3)|
Trash bin or dumpster interiors
|3||No publishable data|
Ditches, channels, trenches, excavations
|203||Trench collapse (166)|
Underground mines, caves, tunnels
|129||Inhalation of a harmful substance (29)|
Sewers, manholes, storm drains
|61||Inhalation of a harmful substance (27)|
Underground mines, mine tunnels
|58||Struck by falling object or equipment (21)|
Confined spaces on vehicles
|45||Inhalation of a harmful substance (20)|
Tanker truck interiors
|20||Inhalation of a harmful substance (16)|
|18||Inhalation of a harmful substance (7)|
|13||Direct exposure to electricity, 220 volts or less (5), Exposure to environmental heat (5)|
|10||Falls to lower level (6)|
 Based on the BLS Occupational Injury and Illness Classification System (OIICS) 2.01 implemented for 2011 data forward. More on OIICS can be found at https://www.bls.gov/iif/definitions/occupational-injuries-and-illnesses-classification-manual.htm.
Certain types of events are linked closely to confined spaces. Trench collapses led to the deaths of 168 workers from 2011 to 2018. 135 of these workers were employed in the private construction industry.
Falls to a lower level accounted for 156 of the 1,030 confined spaces deaths during this period. The most common coded confined spaces in falls are silo, grain bin interiors (17); sewers, manholes, storm drains (16); and ditches, channels, trenches, excavations (15).
There were 126 cases of inhalation of a harmful substance in a single episode in a confined space over the 8-year period. The most common types of inhaled gases were hydrogen sulfide (38 cases), carbon monoxide (23), methane (10), sewer gas (6), and solvents and degreasers (5). In addition to these inhalation cases, there were 39 cases of depletion of oxygen and 21 cases of drowning.
Ninety eight workers were killed in incidents involving confined spaces due to engulfment in other collapsing materials. In total, 66 of these decedents were engulfed in cash grain crops or field crops.
Fires and explosions accounted for 58 cases with explosions being the majority (46).
A total of 56 cases were attributable to being caught in running machinery. In 21 of these cases, the decedent was caught in a powered conveyor, most commonly a conveyor – screw, auger (15).
Many different occupations work in and around confined spaces. The following tables shows the 10 occupations with the largest number of fatal workplace injuries involving confined spaces from 2011-18.
Farmers, ranchers, and other agricultural managers
First-line supervisors of construction trades and extraction workers
Plumbers, pipefitters, and steamfitters
Farmworkers and laborers, crop, nursery, and greenhouse
Laborers and freight, stock, and material movers, hand
Cleaners of vehicle and equipment
Heavy and tractor-trailer truck drivers
Maintenance and repair workers, general
 CFOI has used the Standard Occupation Classification (SOC) 2010 system since 2011 to define occupation. For more information on SOC, see our definitions page at https://www.bls.gov/iif/definitions/census-of-fatal-occupational-injuries-definitions.htm.
Confined spaces are found in workplaces throughout the United States. There are publishable data for fatal occupational injuries involving confined spaces from 2011-18 in 49 states and the District of Columbia. The map below shows the breakout by state.
For technical information and definitions, please see the BLS Handbook of Methods.
You can obtain data from the Injuries, Illnesses, and Fatalities program by using the following tools: Create Customized Tables (Multiple Screens), Create Customized Tables (Single Screen), and the Online Profiles System. Additional tables and charts are on the IIF homepage and the IIF State page.
U.S. Bureau of Labor Statistics. Fatality data are from the Census of Fatal Occupational Injuries. Nonfatal injury and illness data are from the Survey of Occupational Injuries and Illnesses.
1 CFOI has a dedicated data element for identifying confined space incidents. More detail on the type of confined space, where available, comes from the Occupational Injury and Illness Classification System (OIICS) Primary Source and Secondary Source codes. More information on Primary Source and Secondary Source can be found at https://www.bls.gov/iif/definitions/occupational-injuries-and-illnesses-classification-manual.htm. Of the 1,030 fatal occupational injuries involving confined spaces from 2011-18, 643 had a Primary Source or Secondary Source that identified the type of confined space involved.
Last Modified Date: July 15, 2020