Introduction

The Survey of Occupational Injuries and Illnesses is a Federal/State program in which employer report forms are collected from private and public industry employers.  State agencies collect and process the survey data and prepare estimates using standardized procedures established by the Bureau of Labor Statistics (BLS), U.S. Department of Labor to insure uniformity and consistency between states.  The Survey of Occupational Injuries and Illnesses measures nonfatal injuries and illnesses only.  The survey excludes the self-employed, farms with fewer than 11 employees, private households, and Federal government agencies.   The Missouri Department of Labor and Industrial Relations, Research and Analysis Section, in cooperation with the BLS, processes survey reports from approximately 5,500 private industry establishments annually. 

National public sector estimates covering nearly 19 million State and local government workers were available for the first time from the Survey of Occupational Injuries and Illnesses for the reference year 2008.  Data were collected from State and local government establishments in all States in order to produce national public sector estimates. 

The Occupational Safety and Health Act of 1970 implemented regulations requiring most private industry employers to maintain records and prepare reports on work-related injuries and illnesses.  The BLS was given the responsibility to develop a comprehensive statistical system for work-related injuries, illnesses, and deaths in private industry.  In 1972, the BLS, in cooperation with many state governments, designed an annual survey to estimate the number and frequency of work-related injuries and illnesses by detailed industry for the Nation and for States participating in the survey.  The survey information is valuable to the safety community to assist with allocating prevention resources.

In 1992, the survey information on nonfatal incidents involving days away from work was expanded to describe the occupation and other demographic information of workers who incur the work-related injuries and illnesses, the nature of the conditions and how they occurred, and the time away from work.  The survey reports incidence rates of injury and illness cases that allow for comparison among industries and establishments of varying sizes.  Measures of injuries and illnesses are expressed as a constant to allow for a common statistical base across industries regardless of employment size of establishment.  The rates are useful to evaluate the safety performance of a particular industry over time or to compare an industry’s safety record between states.

Industry Classification

The Survey of Occupational Injuries and Illnesses uses the North American Industry Classification System (NAICS) to classify businesses by industry type.  The NAICS recognizes hundreds of new businesses in the United States economy, especially in the service-providing sector.  NAICS classifies establishments into a detailed industry based on the production processes and provided services.

The goods-producing sectors consist of the following industry sectors: agriculture, forestry, fishing, and hunting (NAICS sector 11); mining (NAICS sector 21); construction (NAICS sector 23); and manufacturing (NAICS sector 31-33).  The service-providing sectors include the following industry sectors: wholesale trade (NAICS sector 42); retail trade (NAICS sector 44-45); transportation and warehousing (NAICS sector 48-49); utilities (NAICS sector 22); information (NAICS sector 51); finance and insurance (NAICS sector 52); real estate and rental and leasing (NAICS sector 53); professional, scientific, and technical services (NAICS sector 54); management of companies and enterprises (NAICS sector 55); administrative and support and waste management and remediation services (NAICS sector 56); educational services (NAICS sector 61); health care and social assistance (NAICS sector 62); arts, entertainment, and recreation (NAICS sector 71); accommodation and food services (NAICS sector 72); other services (except public administration) (NAICS sector 81); and public administration (NAICS sector 92).

The BLS grouped related sectors into major industry sectors to help standardize the industry aggregations above the NAICS level.  There are three goods-producing major industry sectors.  Natural resources and mining is the aggregate of sector 11 (agriculture, forestry, fishing, and hunting) and sector 21 (mining).  Construction is the aggregate of sector 23 (construction).  Manufacturing is the aggregate for sector 31-33 (manufacturing).  There are eight service-providing major industry sectors.  Trade, transportation, and utilities is the aggregate for sector 42 (wholesale trade), sector 44-45 (retail trade), sector 48-49 (transportation and warehousing), and sector 22 (utilities).  Information is the aggregate for sector 51 (information).  Financial activities is the aggregate for sector 52 (finance and insurance) and sector 53 (real estate and rental and leasing).  Professional and business services is the aggregate of sector 54 (professional, scientific, and technical services), sector 55 (management of companies and enterprises), and sector 56 (administrative and support and waste management and remediation services).  Education and health services is the aggregate of sector 61 (educational services) and sector 62 (health care and social assistance).  Leisure and hospitality is the aggregate for sector 71 (arts, entertainment, and recreation) and sector 72 (accommodation and food services).  Other services is the aggregate for sector 81 (other services, except public administration).  Public administration is the aggregate for sector 92 (public administration).  The BLS has generated estimates of injuries and illnesses for many of the 2-, 3-, 4-, 5-, and 6-digit private sector industries as defined in the North American Industry Classification Manual, as well as for major industry sectors, total of all goods-producing sectors, and total of all service-providing sectors.

The Mine Safety and Health Administration of the U.S. Department of Labor provides occupational injury and illness data for coal, metal, and nonmetal mining.  This agency did not adopt the revised OSHA recordkeeping requirements effective January 1, 2002, so estimates for these industries are not comparable with estimates for other industries.  The Federal Railroad Administration of the U.S. Department of Transportation provides data for rail transportation.

Survey Records

The incidence rates and numbers of injury and illness cases are based on logs and records kept by employers throughout the calendar year.  Information from the logs is used by the survey to develop estimates of the numbers and incidence rates of nonfatal occupational injuries and illnesses.  The BLS survey collects the number of hours worked to be used to determine industry and case characteristics incidence rates.  The survey records reflect the year’s occupational injuries and illnesses as well as the employer’s comprehension of which cases are work related using the record-keeping guidelines of the U.S. Department of Labor.  Changes in the level of economic activity, working conditions and work practices, worker experience and training, and the number of hours worked can have an effect on the number of injuries and illnesses reported in a given year.

The BLS Survey of Occupational Injuries and Illnesses provides information on characteristics, such as occupation, age, sex, race, and length of service, of occupational injuries and illnesses involving days away from work.  The survey also includes data concerning the circumstances of the injury or illness, including nature of the injury or illness, part of body affected, event or exposure, and primary and secondary sources of the injury or illness.

Nonfatal Occupational Injuries and Illnesses

Nonfatal occupational injuries are defined as involving one or more of the following: loss of consciousness, restriction of work or motion, transfer to another job, or medical treatment (other than first aid).  An occupational injury is an injury, such as a cut, fracture, sprain, strain, amputation, etc., that results from a work event or from a single instantaneous exposure in the work environment.

An occupational illness is defined as any abnormal condition or disorder, other than one resulting from an occupational injury, caused by exposure to factors associated with employment.  Occupational illnesses include acute and chronic illnesses or diseases that may be caused by inhalation, absorption, ingestion, or direct contact.

Cases with Days Away from Work, Job Transfer, or Restriction

Cases with days away from work, job transfer, or restriction involved recuperation away from work, transfer to another job, restricted duties at work, or a combination of these actions.  Other recordable cases did not result in time away from work.  There are two types of cases with days away from work, job transfer or restriction.  The first type requires at least one day away from work, with or without job transfer or restricted work activity.  The second type requires only job transfer or restriction.  Job transfer or restriction cases may involve shortened work hours, a temporary job change, or temporary restrictions on certain duties of a worker’s regular job.  Incidence rates denote the number of injuries and/or illnesses per a specified number of full-time workers.

Survey Estimates

The survey estimates for the characteristics of cases with days away from work are based on a scientifically selected probability sample instead of a census of the entire industry population.  Industry establishments were selected to represent themselves and other establishments of the same industry and employment size that were not selected to participate in the survey for the reporting year.  Selected establishments that were anticipated to have large numbers of days away from work cases were given instructions prior to the survey on how to sample the cases to minimize the burden of their response.

A standard error is calculated to determine the precision of each injury and illness estimate.  The standard error defines a confidence interval (range) around the estimate.  The approximate 95 percent confidence interval is the estimate plus or minus two times the standard error.  The standard error can be expressed as the relative standard error, or percent of the estimate.  At the 95 percent confidence level, one can be 95 percent confident that the actual incidence rate falls within the confidence interval.

Survey Users

The survey can be used as an indicator of the magnitude of occupational safety and health problems.  The statistics can help determine which industries need to improve safety programs and to assess the effectiveness of the Occupational Safety and Health Act in reducing work related injuries and illnesses.  Labor and management can use the estimates obtained in the survey to evaluate safety programs.  Other users include insurance carriers involved in workers’ compensation, industrial hygienists, manufacturers of safety equipment, researchers, and others concerned with job safety and health.

Summary Data

Summary data presents numbers and incidence rates of nonfatal occupational injuries and illnesses in Missouri industry.  Data are presented for industries and industry sectors classified by NAICS codes.  Numbers and incidence rates of occupational injuries and illnesses are presented for different types of cases.

Incidence rates and numbers of occupational illnesses are presented by category of illness.  The categories of illnesses are: total cases; skin disorders; respiratory conditions; poisonings; hearing loss; and all other illnesses. 

Incidence Rate Calculations

The incidence rates represent the number of injuries and illnesses per 100 full-time workers and were calculated as: (N/EH) x 200,000 where
N                         = number of injuries and illnesses
EH                       = total hours worked by all employees during the calendar year
200,000              = base for 100 equivalent full-time workers (working 40 hours per week, 50 weeks per year).

The incidence rates are presented for total recordable cases; cases with days away from work, job transfer, or restriction; and other recordable cases. 

Incidence rates of nonfatal occupational illnesses represent the number of illnesses per 10,000 full-time workers and were calculated as: (N/EH) x 20,000,000 where
N                         = number of illnesses
EH                       = total hours worked by all employees during the calendar year
20,000,000         = base for 10,000 equivalent full-time workers (working 40 hours per week, 50 weeks per year).

Case and Demographic Data

The most serious nonfatal occupational injury and illness cases involve lost work-time.  One measure of the severity of lost work-time cases is the percent distribution.  A second measure of the severity of lost work-time cases is the median number of lost workdays.  The median days away from work designates the point at which half the cases involved more days and half the cases involved fewer days. 

Demographic information provides details of characteristics of the injured or ill worker.  This information includes occupation, gender, age of worker, occupational group, length of service with employer at the time of the incident, and race or ethnic origin.  Four case characteristics are used to describe each nonfatal occupational injury or illness.  The nature of the injury or illness identifies the principal characteristics, or physical effects, of the injury or illness.  The part of body affected is identified for the involved worker.  The source of injury or illness identifies the object, substance, bodily motion, or exposure that directly produced or inflicted the injury or illness.  The event or exposure describes the manner in which the injury or illness was produced or inflicted by the source of the injury or illness.

Incidence Rate Calculations

Incidence rates represent the number of injuries and illnesses per 10,000 full-time workers and were calculated as: (N/EH) x 20,000,000 where
N                          = number of injuries and illnesses
EH                        = total hours worked by all employees during calendar year
20,000,000          = base for 10,000 equivalent full-time workers (working 40 hours per week, 50 weeks per year).