Article

October 2013

Using workplace safety and health data for injury prevention

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Sequence of events

When is a fall not a fall? Perhaps when a person is pushed. Likewise, when is an explosion not an explosion? Perhaps when it is caused by a forklift driven into a gas canister. Employee injuries, when taken at face value, may appear to be the result of one event, but, in reality, the underlying event may be different. Understanding this underlying event is important in allocating prevention resources. For fatal work injuries and the most severe nonfatal work injuries and illnesses, BLS identifies a number of characteristics of the case, including the manner in which the injury occurred (known as the “event or exposure” and typically referred to as “event”). Beginning with data for 2011, event coding has been based on an order of precedence designed to identify the underlying cause of an incident. In the first example above, the underlying cause of the fall (being pushed) is an act inflicted by another person; likewise, the underlying cause of the explosion in the second example is a transportation incident (forklift driven into a gas canister). Directing resources toward greater prevention of fall or explosion incidents, while no doubt important, might not directly lessen the likelihood of these events.

BLS identifies many events or exposures, grouped into seven broad categories in order of precedence (that is, the event that comes first on the list is considered the event of record). The order of precedence is as follows:

1.      Violence and other injuries by persons or animals

2.      Transportation incidents

3.      Fires and explosions

4.      Falls, slips, and trips

5.      Exposure to harmful substances or environments

6.      Contact with objects and equipment

7.      Overexertion and bodily reaction

As a result of the now strict adherence to the order of precedence, some events are presently classified in categories that are different from those used in the past. For example, unintentional shootings, which in the past would be included in contact with objects or equipment, are now included in violence and other injuries by persons or animals. Table 1 identifies several case circumstances for two incidents in which the event could be classified into one of several categories. The order of precedence can be used as one means of identifying the root cause of each incident.

Table 1. Determining the sequence of events
Incident example 1
CircumstancesEvent or exposure
categories(1)
Correct code

(1) Worker on 2nd-story roof
(2) Worker argues with coworker
(3) Coworker pushes worker backwards
(4) Worker takes step back and trips on skylight railing
(5) Worker falls to ground, fractures skull, and dies

 

 

 

 

 

 

Violence and other injuries by persons or animals
Transportation incidents
Fires and explosions
Falls, slips, and trips
Exposure to harmful substances or environments
Contact with objects and equipment
Overexertion and bodily reaction
Incident example 2
CircumstancesEvent or exposure
categories(1)
Correct code

(1) Worker driving forklift in warehouse 
(2) While turning sharply, one fork strikes a pressurized container filled with flammable gas 
(3) Container falls to ground and ignites, causing fire 
(4) Worker suffers third degree burns to lower leg

 

 

 

 

 

 

Violence and other injuries by persons or animals
Transportation incidents
Fires and explosions
Falls, slips, and trips
Exposure to harmful substances or environments
Contact with objects and equipment
Overexertion and bodily reaction

Notes:

(1) Possible event coding shown in italics.

In describing the change in coding of events or exposures, BLS indicates that the category violence and other injuries by persons or animals

now includes more distinct coding of intentional acts, unintentional acts, and acts of unknown intent . . . . The share represented by this division is likely to increase [from previous coding] . . . . All injuries resulting from direct human contact are now explicitly included in this division, whether or not the injury could be defined as an assault. For example, an injury to a physical education teacher during a kickball game, to a police officer during a training exercise, to a professional football player during a game, and to a worker injured by a coworker during horseplay will all be classified into violence and other injuries by persons or animals. In addition, the new division includes codes for unintentional shootings.4

Looking at data under the new coding system provides some evidence for a shift of nonfatal cases into the “violence” category.5 In 2010, under the old system, 18 percent of fatal work injuries and 4 percent of nonfatal work injuries and illnesses resulting in days away from work were classified as assaults and violent acts; in 2011, under the new system, 17 percent of fatal work injuries and 6 percent of nonfatal work injuries and illnesses were classified as violence and other injuries by persons or animals.

Frequency of incidents

How often do workplace injuries and illnesses occur in your establishment? For many employers, the requirement to post an Occupational Safety and Health Administration (OSHA) injury and illness log each year provides one opportunity to assess worker safety issues. But that log may have little value unless it can be compared against such benchmarks as nationwide or industry totals or against data for a specific state. Such data are available on the BLS website and from many states that partner with BLS to capture and present these data. Further, a simple application on the BLS website allows anyone to compute an injury and illness rate and to view comparisons by industry and state. Figure 1 demonstrates the BLS incidence rate calculator and comparison tool and provides an example of available results.

Notes

4 Northwood, Sygnatur, and Windau, “Updated BLS Occupational Injury and Illness Classification System.”

5 Data users should be cautious about placing too much emphasis on differences between 2010 and 2011 data. Because the definitions used before and after the transition to the new classification system are different, it is not possible to compute variance data to validate those differences. When data over several years are available, looking at them may help establish trends that result from the new classification system.

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About the Author

William J. Wiatrowski
wiatrowski.william@bls.gov

William J. Wiatrowski is an economist in the Office of Compensation and Working Conditions, Bureau of Labor Statistics.