United States

Organization responsible for the statistics

US Department of Labor, Bureau of Labor Statistics.

State agencies participate in the collection of the data, but the Bureau of Labor Statistics provides partial funding and is responsible for maintaining uniform programme requirements.

Periodicity

Annual.

Source

Survey of Occupational Injuries and Illnesses (a survey of establishments). The survey generates nationwide estimates of non-fatal work-related injuries and illnesses; the Census of Fatal Occupational Injuries compiles data for fatal work injuries (see below under Additional information).

Objectives and users

The Occupational Safety and Health Act of 1970 (PL 91-596) requires the Secretary of Labor to develop and maintain an effective programme for the collection, compilation and analysis of statistics on occupational safety and health. Together, the two programmes comprising the Survey of Occupational Injuries and Illnesses and the Census of Fatal Occupational Injuries provide information that is critical to designing and implementing effective public policy in safety and health.

Major users:

the safety and health community, including officials in industrial and other enterprises, public policy makers, labour unions, academia and insurance institutions.

Coverage

The coverage of the survey is determined by the Occupational Safety and Health Act of 1970 (PL 91-596).

Data for employees covered by other Federal safety and health legislation are provided by the Mine Safety and Health Administration of the US Department of Labor and the Federal Railroad Administration of the US Department of Transportation.

Persons:

Paid employees and volunteer workers who receive compensation, including non-monetary benefits. The self-employed are excluded.

In 1994, the annual average number of employees in the private sector covered by the survey was about 95,449,300.

Economic activities:

All economic activities, except local, State and Federal government and service activities in private households.

Geographic areas:

The whole country, i.e. the 50 States and the District of Columbia. The statistics do not cover the territories of the United States (i.e. Guam, Puerto Rico, the US Virgin Islands and American Samoa).

Injuries occurring to persons working outside the country are not included in the statistics, which cover only persons employed in the area covered at the time of the injury or illness.

Establishments:

All types and sizes of establishments, except farms with fewer than 11 employees.

Types of occupational accidents covered

The statistics cover non-fatal occupational injuries 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 (i.e. one-time treatment, and any follow-up visit for the purpose of observation, of minor scratches, cuts, burns, splinters, etc., which do not ordinarily require medical care).

Data are complied for occupational injuries and diseases combined, and for occupational injuries and occupational diseases separately. The injuries are those recorded by employers, in accordance with the Occupational Safety and Health Act of 1970.

Commuting accidents are not included.

Concepts and definitions

(Source: Occupational Safety and Health Act of 1970).

Occupational injury:

any injury such as a cut, fracture, sprain, amputation, etc., which results from a work-related event or from a single instantaneous exposure in the work environment.

Worktime lost:

the number of workdays on which the injured employee would have worked but could not, excluding the day of the injury.

Lost workdays cases involving days away from work:

those cases which result in days away from work, or a combination of days away from work and days of restricted work activity.

Cases involving days of restricted work activity:

those cases which result only in restricted work activity, i.e. the days on which, because of injury or illness, the employee was assigned to another job on a temporary basis, worked at a permanent job less than full time, or worked at a permanently assigned job but could not perform all duties normally connected with it.

The unit of measure used in the statistics is the case of injury or illness.

Minimum period of absence from work: none.

(The statistics supplied to the ILO for publication in the Yearbook of Labour Statistics refer to injuries and illness with lost workdays, i.e. with a minimum absence of one day, excluding the day of the accident).

Maximum period for death to be considered a fatal occupational injury: not relevant.

Types of information compiled

Information listed under (a) to (d) is compiled only for injuries and illnesses involving days away from work.

(a) personal characteristics of persons injured: sex, age, race or ethnic background, occupation and length of service in the establishment;

(b) amount of worktime lost: the number of days away from work;

(c) characteristics of accidents: event(s) that occurred causing the injury or illness; source of the injury or illness;

(d) characteristics of injuries: part of body affected; nature of the injury or illness;

(e) characteristics of employers or workplaces: economic activity (for all employers, whether or not there were any occupational injuries or illnesses).

Measurement of worktime lost

Worktime lost is measured in workdays, for cases resulting in days away from work only. It is not measured for cases of permanent incapacity to work. Temporary absences, e.g. of less than one day, for medical treatment are not counted as worktime lost.

Classifications

(a) fatal or non-fatal accidents:

not relevant;

(b) extent of disability:

none;

(c) economic activity:

according to the Standard Industrial Classification;

(d) occupation:

according to the classification structure developed by the Bureau of the Census, US Department of Commerce;

(e) type of injury:

characteristics of the case: the coding structure developed by the Bureau of Labor Statistics is hierarchical and provides detail up to the four-digit level; the following gives the Occupational Injury and Illness Classification Structure at the two-digit level:

nature of injury or illness: traumatic injuries and disorders (traumatic injuries and disorders, unspecified; traumatic injuries to bones, nerves, spinal cord; traumatic injuries to muscles, tendons, ligaments, joints, etc.; open wounds; surface wounds; burns; intracranial injuries; effects of environmental conditions; multiple traumatic injuries and disorders; other traumatic injuries and disorders); systemic diseases and disorders (systemic diseases and disorders, unspecified; diseases of the blood and blood forming organs; nervous system and sense organ diseases; circulatory system diseases; respiratory system diseases; digestive system diseases and disorders; genitourinary system diseases and disorders; musculoskeletal system and connective tissue diseases and disorders; disorders of the skin and subcutaneous tissue; other systemic diseases and disorders); infectious and parasitic diseases (infectious and parasitic diseases, unspecified; bacterial diseases; viral diseases; other arthropod-borne diseases; mycoses; helminthiases; infectious diseases peculiar to the intestines; other infectious and parasitic diseases); neoplasms, tumours and cancer (malignant neoplasms and tumours (cancers, carcinomas, sarcomas); benign neoplasms and tumours; neoplasms and tumours of unknown properties); symptoms, signs and ill-defined conditions (symptoms, signs and ill-defined conditions, unspecified; symptoms; abnormal findings; multiple symptoms, signs and ill-defined conditions; symptoms, signs and ill-defined conditions, not elsewhere classified); other diseases, conditions and disorders (damage to prosthetic devices; mental disorders or syndromes; other diseases, conditions and disorders, not elsewhere classified); multiple diseases, conditions and disorders; non-classifiable;

part of body: head (head, unspecified; cranial region, including skull; ear(s); face; multiple head locations; head, not elsewhere classified); neck, including throat (neck, except internal location of diseases or disorders; internal neck location, unspecified; vocal cord(s); larynx; laryngopharynx; pharynx; trachea; multiple internal neck locations; internal neck location, not elsewhere classified); trunk (trunk, unspecified; shoulder, including clavicle, scapula; chest, including ribs, internal organs; back, including spine, spinal cord; abdomen; pelvic region; multiple trunk locations; trunk, not elsewhere classified); upper extremities (upper extremities, unspecified; arm(s); wrist(s); hand(s), except fingers; finger(s), fingernail(s); multiple upper extremities locations; upper extremities, not elsewhere classified); lower extremities (lower extremities, unspecified; leg(s); ankle(s); foot(feet), except toes; toe(s), toenail(s); multiple lower extremities locations; lower extremities, not elsewhere classified); body systems; multiple body parts; other body parts (prosthetic devices; other body parts, not elsewhere classified; non-classifiable);

(f) cause of accident:

source of injury or illness: chemicals and chemical products (chemicals and chemical products, unspecified; acids; alkalies; aromatics and hydrocarbon derivatives, except halogenated; halogens and halogen compounds; metallic particulates, trace elements, dusts, powders, fumes; agricultural chemicals and other pesticides; chemical products, general; coal, natural gas, petroleum fuels and products, not elsewhere classified; other chemicals); containers (containers, unspecified; containers - non-pressurized; containers - pressurized; containers - variable restraint; dishes, drinking cups, beverage glasses; luggage, handbags; skids, pallets; containers, not elsewhere classified); furniture and fixtures (furniture and fixtures, unspecified; cases, cabinets, racks, shelves; floor, wall, window coverings; furniture; other fixtures; furniture and fixtures, not elsewhere classified); machinery (machinery, unspecified; agricultural and garden machinery; construction, logging and mining machinery; heating, cooling and cleaning machinery and appliances; material handling machinery; metal, woodworking and special material machinery; office and business machinery; special process machinery; miscellaneous machinery); parts and materials (parts and materials, unspecified; building materials - solid elements; fasteners, connectors, ropes, ties; hoisting accessories; machine, tool and electric parts; metal materials - non-structural; tars, sealants, caulking, insulating material; tarps and sheeting - non-metal; vehicle and mobile equipment parts; parts and materials, not elsewhere classified); person, plants, animals and minerals (animals and animal products; food products - fresh or processed; infectious and parasitic agents; metallic minerals; non-metallic minerals, except fuel; person - injured or ill worker; person - other than injured or ill worker; plants, trees, vegetation - not processed; persons, plants, animals and minerals, not elsewhere classified); structures and surfaces (structures and surfaces, unspecified; building systems; floors, walkways, ground surfaces; other structural elements; structures; structures and surfaces, not elsewhere classified); tools, instruments and equipment; tools, instruments and equipment, unspecified; hand tools - non-powered; hand tools - powered; hand tools - power not determined; ladders; medical and surgical instruments; photographic equipment; protective equipment, except clothing; recreation and athletic equipment; other tools, instruments and equipment, not elsewhere classified); vehicles (vehicles, unspecified; air vehicle; highway vehicle, motorized; highway vehicle, non-motorized; off road vehicle, non-industrial; plant and industrial powered vehicles, tractors; plant and industrial vehicles - non-powered; rail vehicle; water vehicle; vehicles, not elsewhere class ified); other sources (ammunition; apparel and textiles; atmospheric and environmental conditions; paper, books, magazines; scrap, waste, debris; steam, vapours, liquids, not elsewhere classified; other sources, not elsewhere classified; non-classifiable);

event: contact with objects and equipment (contact with objects and equipment, unspecified; struck against object; struck by object; caught in or compressed by equipment or objects; caught in or crushed in collapsing materials; rubbed or abraded by friction or pressure; rubbed, abraded or jarred by vibration; contact with objects and equipment, not elsewhere classified); falls (fall, unspecified; fall to lower level; jump to lower level; fall on same level; fall, not elsewhere classified); bodily reaction and exertion (bodily reaction and exertion, unspecified; bodily reaction; overexertion; repetitive motion; sustained viewing; bodily conditions, not elsewhere classified; bodily reaction and exertion, not elsewhere classified); exposure to harmful substances or environments (exposure to harmful substances or environments, unspecified; contact with electric current; contact with temperature extremes; exposure to air pressure changes; exposure to caustic, noxious or allergenic substances; exposure to noise; exposure to radiation; exposure to traumatic or stressful event, not elsewhere classified; oxygen deficiency, not elsewhere classified; exposure to harmful substances or environments, not elsewhere classified); transportation accidents; transportation accident, unspecified; highway accident; non-highway accident, except rail, air, water; pedestrian, non-passenger struck by vehicle, mobile equipment; railway accident; water vehicle accident; aircraft accident; transportation accident, not elsewhere classified); fires and explosions (fire or explosion, unspecified; fire - unintended or uncontrolled; explosion); assaults and violent acts (assaults and violent acts, unspecified; assaults and violent acts by person; self-inflicted injury; assaults by animals); other events or exposures (non-classifiable);

(g) duration of absence from work:

one day, two days, three to five days, 6 to ten days, 11 to 20 days, 21 to 30 days, 31 days or more;

(h) characteristics of workers:

age, sex, race or ethnic group (white, not of Hispanic origin; black, not of Hispanic origin; Hispanic; asian or Pacific islander; American Indian or Alaskan Indian); length of service (less than three months; three to twelve months; one to five years; more than five years);

(i) characteristics of accidents:

none;

(j) characteristics of employers or workplaces:

employment size.

Crossclassifications:

all the variables listed above are used for crossclassifications.

Reference period

Year.

A case of injury or illness is included in the statistics for the period in which the accident occurred.

Worktime lost is included in the statistics for the period in which the accident occurred; it may include time lost beyond the reference year.

Estimates

Total number of cases of injury or illness, for selected characteristics.

Median number of days away from work, for selected characteristics.

Percentage distributions of cases of injury or illness and days away from work, for selected characteristics.

Selected data from the survey, such as length of service with the employer, are also used to produce weighted estimates: e.g. the percentage of all cases with less than three months' tenure and involving a certain number of days away from work.

Incidence rates: the number of cases of injury or illness per 100 full-time workers, estimated as: N / EH x 200,000

where:

N = number of cases of injury or illness

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 for 50 weeks per year)

Incidence rates per 10,000 full-time workers are similarly calculated for illnesses and for selected characteristics.

Incidence rates are calculated for all cases of injury, injuries with lost worktime and injuries without lost worktime. They are also calculated for selected characteristics.

Historical background of the series

The Bureau of Labor Statistics has developed data on safety and health conditions for workers since 1912, with the introduction of series on industrial accidents in the iron and steel industries. Subsequent Bureau studies reflected a growing concern for workers disabled on the job, and were helpful in the development of the present workers' compensation system.

It was not until the passage of the Occupational Safety and Health Act of 1970 that the Bureau of Labor Statistics was given responsibility for developing a comprehensive system of statistics covering all work-related deaths, injuries and illnesses. Shortly after, the Bureau, in cooperation with many State governments, designed an annual survey to estimate the number and frequency of work-related injuries and illnesses throughout the country and for several hundred individual economic activities. Statistics of occupational injuries and diseases are available for the whole country as from 1972.

In 1992, the survey first began to collect information on the demographic and case characteristics of injuries involving days away from work, as well as the number of days away from work associated with these cases and their characteristics. A separate census of fatal occupational injuries was also developed (see below).

Documentation

Series available:

The following summary tables are published:

The following sets of tables showing the characteristics of cases of injury or illness are also published:

Bibliographic references:

The data are published in:

US Department of Labor, Bureau of Labor Statistics: Occupational Injuries and Illnesses: Counts, Rates and Characteristics (annual).

idem: Workplace injuries and illnesses (Press release, annual).

idem: Characteristics of injuries and illnesses resulting in absences from work (Press release, annual).

In addition, analytical articles are published periodically in US Department of Labor: Monthly Labor Review and Compensation and Working Conditions.

Methodological information is published in Occupational Injuries and Illness: Counts, Rates and Characteristics (op cit.), and in the Bureau of Labor Statistics: Handbook of Methods.

Not all the data are published because of space limitations in the annual bulletin. If data are publishable, but not published, they can be made available on request addressed to the Bureau of Labor Statistics. Data are also available on the World Wide Web (BLS World Wide Web site: www.bls.gov).

Data on rates of injury and illness from 1981 to the most recent year, classified at the two-digit level of the Standard Industrial Classification (SIC). Injury and illness rates from 1976 to the most recent year classified at the two-, three- and four-digit level of the SIC are available on tape.

Data published by ILO:

The following data are furnished regularly to the ILO for publication in the Yearbook of Labour Statistics, relating to reported injuries (including occupational diseases) according to major division of economic activity: number of persons injured (cases of injury or illness) with lost workdays. Data on the number of fatal injuries and rates of fatal injuries were provided up to 1991, and the number of workdays lost up to 1992. The number of persons at risk (total number of employees in private industry) is also supplied and stored in the LABORSTA database.

Confidentiality:

Information relating to individual companies is considered confidential and information which could reveal company-specific information is also considered confidential. Estimates for individual economic activities are not published if one of the following situations occurs:
  1. estimates for the activity are based on reports from fewer than three establishments; or, if three or more establishments report data for the activity, one employs more than 60 per cent of the workers; or if there were fewer than six employees in the industry;
  2. average employment for the activity was less than 10,000 in the survey year; however, data for an activity with an annual average employment of less than 10,000 may be published if the majority of the employment was reported in the survey;
  3. the relative standard error on total cases for the activity at one standard error was more than a specified limit;
  4. the benchmark factor for the activity was less than 0.90 or greater than 1.49.

    Data that are not published for a particular activity are included in the total for the broader group of which it is a part. In addition, selected items of data are suppressed for publishable activities if the sampling error for the estimate is 100 per cent or above.

International standards

The Occupational Safety and Health Act of 1970 (PL 91-596) was the source of the requirements of the statistical system. The international statistical standards and guidelines were not followed.

Input from all parties interested in statistics on occupational safety and health is solicited in the Federal Register. Both formal and informal meetings are held with representatives of the interested groups. For example, the National Academy of Science provided input to the current survey design. The Bureau of Labor Statistics continuously invites ideas from users and experts in business, labour, professional and academic organizations, and from members of the public. The Commissioner for Labour Statistics established two standing advisory committees in 1947: the Business Research Advisory Council and the Labor Research Advisory Council. A third council, the State Research Advisory Committee on Occupational Safety and Health was in existence from 1989 to 1994. These councils advise on technical problems and provide views on Bureau programmes in relation to the needs of their members.

Method of data collection

Type of survey:

Establishment survey.

Types of data collected:

The form used in the survey consists of the following:

Name and address of the establishment (prefilled from the information in the State Unemployment Insurance lists.

Part 1: summary of occupational injuries and illness, to be completed by all establishments in the sample, even if there were no occupational injuries or illnesses during the reference year:

Part 2: information about cases with days away from work: for each case (up to four are provided for in the form):

Provision is included in the form for any comments respondents may wish to add regarding the survey.

Universe of the survey:

The sample is selected to represent all private sector activities throughout the country. The universe file which provides the sample frame is derived from the State Unemployment Insurance lists of all employers.

Sampling:

A sample of about 250,000 establishments is selected by the Bureau of Labor Statistics each year, using stratified random sampling with a Neyman allocation and a ratio estimator. The sample is designed to produce data at the two-digit level of the SIC for agriculture, forestry and fishing; at the four-digit level for manufacturing; and at the three-digit level for the other activities covered.

The sampling unit is the establishment, defined as a single physical location where business is conducted or where services or industrial operations are performed. The sampling units are stratified by State, size (number of employees) and economic activity, and an independent sample is selected for each State, so as to permit the data needs of participating State agencies. The largest establishments are all included in the sample; smaller establishments are selected in proportion to size. Thus, the largest establishments are included in the sample each year, while the smaller ones are selected less frequently.

There is no replacement of sampling units in the case of non-response.

Field work:

Early each year, State agencies mail the questionnaires to the selected establishments, to collect information referring to the previous calendar year. For those States not participating in the programme, the questionnaires are mailed by the Bureau of Labor Statistics. Each employer completes a single form which is used for both national and State estimates of occupational injuries and illnesses. This procedure eliminates duplicate reporting by respondents and, together with the use of identical survey techniques at the national and State levels, ensures maximum comparability of estimates.

Information for the injury and illness portion of the form is copied directly from the employer records of occupational injuries and illnesses.

The responses are generally received around the middle of the year.

Data processing:

The data are entered on a PC-based data capture computer system.

The system checks each summary data element for validity, the summary record for consistency, and for consistency between data elements on the summary form and its related case forms. This edit process identifies invalid and questionable conditions that must be reviewed and clarified. Values in selected data fields on usable records are imputed if the employer failed to provided the data or if the data did not pass the edit criteria. Both demographic and case characteristics from the Days away from work case forms are coded and entered into the system.

The employer may be recontacted by telephone or letter if no response has been obtained or if data need to be clarified.

Estimates:

The sample units are constructed to represent all units in the size class-activity cell by means of a weighting procedure. The sample unit weight for a particular size class and economic activity is determined by the inverse of the sampling ratio for that size-class/activity cell from which the unit was selected. Because a small portion of the survey forms are not returned, weights are adjusted to account for non-respondents. Weighted estimates for an individual estimating cell are produced using the following formula:

Xi = Σj W ij Xij

where:

Xi = weighted estimate of characteristics, e.g. number of cases reported, in size class i

Wij = weight of sample unit (establishment) j, in size class i, adjusted for frame and collection problems

Xij = characteristics reported by sample unit j, in size class i

If a respondent provides data that do not cover exactly the original sample unit, the sample unit's weight may be adjusted.

Benchmarking adjusts the data to reflect employment levels for the year surveyed. The universe file which provides the sample frame uses older data. The benchmarking procedure uses more recent employment data. Totals are estimated in an individual estimating cell using the weighted estimate of the characteristics.

Reliability of the estimates:

The sample frame is designed to cover all establishments in the target population.

The standard error varies according to the estimate which is examined. At the level of the private sector for total recordable cases, the error may be one per cent; for a specific category of illness in a specific small economic activity, the error may be above 50 per cent.

The sampling variance is estimated using a linearization formula.

Non-sampling errors in the estimates may be attributed to many sources, including the inability to obtain information about all the cases in the sample units, differences in the interpretation of questions, inability or unwillingness of respondents to provide the correct information, mistakes in recording or coding the data, definitional difficulties, and estimations for missing data.

Changes planned:

None.

Additional information

Record-keeping and reporting of occupational injuries and illnesses

The Occupational Safety and Health (OSH) Act of 1970 requires covered employers to prepare and maintain records of occupational injuries and illnesses. The Occupational Safety and Health Administration of the US Department of Labor is responsible for administering the record-keeping system established by the act. Nearly all private sector employers are covered by the OSHA, except small farms with fewer than 11 employees. All employees and volunteers who receive compensation in those establishments are covered.

Two forms are used for OSHA record-keeping in the establishment. One (OSHA No. 200) serves two purposes: (a) as the Log of Occupational Injuries and Illnesses, on which the occurrence, extent and outcome of cases are recorded during the year, and (b) as the Summary of Occupational Injuries and Illnesses which summarizes the log at the end of the year. The other form, the Supplementary Record of Occupational Injuries and Illnesses (OSHA No. 101) provides additional information on each of the cases that have been recorded on the log, recording a description of how the injury or illness exposure occurred, a list of the objects or substances involved, and an indication of the nature of the injury or illness and the part of the body affected.

Ordinarily, injury and illness records must be kept for each establishment covered by the OSH Act. The regulations require that records be located and maintained at this level to assist government agencies administering and enforcing the act, to increase employer and employee awareness and to promote injury and illness prevention. The following cases should be recorded: every occupational death, every non-fatal occupational illness and those non-fatal occupational injuries 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.

The OSH Act requires employers to make periodic reports of deaths,injuries and illnesses which have been recorded on the OSHA injury and illness records. This periodic reporting is accomplished through the Annual Survey of Occupational Injuries and Illnesses described above, and the Census of Fatal Occupational Injuries described below.

Census of Fatal Occupational Injuries

The Census of Fatal Occupational Injuries is carried out each year by the Bureau of Labor Statistics. The data are the most complete count of fatal occupational injuries and provide information that is needed for the design and implementation of effective public policy in safety and health. The Census was initiated in 1992, as studies had shown that fatal work injuries were rare events in the workplace, and could not be covered sufficiently well using probability samples, as in the Survey of Occupational Injuries and Illnesses.

Coverage: The Census covers all employees and self-employed persons in all economic activities throughout the country (about 124,000,000 persons on average in 1994).

Types of occupational accidents covered: The statistics relate to all types of fatal occupational injuries. Deaths due to commuting accidents are not included. For a fatality to be included, the person must have been employed (i.e. working for pay, compensation or profit) at the time of the event, engaged in a legal work activity or present at the site of the incident as a requirement of the job.

Concepts and definitions: An occupational injury is defined as any intentional or unintentional wound or damage to the body resulting from acute exposure to energy, such as heat or electricity, or kinetic energy from a crash; or from the absence of such essentials as heat or oxygen caused by a specific event, incident, or series of events within a single workday or shift. Included are open wounds, intracranial and internal injuries, heatstroke, hypothermia, asphyxiations, acute poisonings resulting from a short-term exposure limited to the worker's shift, suicides and homicides and work injuries listed as underlying or contributory to the cause of death.

Any death that was the result of an occupational injury is counted regardless of the lapse of time between the injury and the death. However, deaths occurring within 30 days of the injury are also reported, for comparison with other statistics.

Types of information compiled:

The following data elements are recorded for each fatality:

These items are used for classifications and crossclassifications.

Reference period: Fatalities are included in the statistics for the period in which the death occurred.

Documentation: The data are published in US Department of Labor, Bureau of Labor Statistics: Fatal workplace injuries: A collection of data and analysis (annual), which also contains research papers. Data for 1993 were published in 1995. Methodological information is included in this publication and in the Bureau of Labor Statistics Handbook of Methods. Because the current methodology differs from that used in previous years, no data from the Census have yet been supplied to the ILO for publication in the Yearbook of Labour Statistics.

Not all the data are published because of space limitations. Additional data that meet publication standards are available on request addressed to the Bureau of Labor Statistics. Data are available to the public in printed form only, although some data are also available on the World Wide Web (BLS World Wide Web site: http://www.bls.gov).

Method of data collection: The Census is carried out on a contractual basis with States; operating costs are shared equally between the States and the US Federal Government.

The data are collected on an ongoing basis during the calendar year, from various source documents, such as death certificates, workers' compensation reports, Federal reports (OSHA) and newspaper articles. A follow-up questionnaire is used in about 20 per cent of the cases to solicit missing information about the incident. The employer may be recontacted by mail or letter, or both, if no response has been obtained or if data need to be clarified. The information is coded by the States and entered into a computer system which edits data for validity and consistency between data elements. This edit process identifies invalid and questionable conditions that should be reviewed and clarified. Records are also sampled and independently coded manually, then the codes compared to ensure that the coded information is consistent and that there are no systematic errors. If significant errors are found in the coding, the entire batch of records is reviewed manually for accuracy.