Oregon Administrative Rules
Chapter 437 - DEPARTMENT OF CONSUMER AND BUSINESS SERVICES, OREGON OCCUPATIONAL SAFETY AND HEALTH DIVISION
Division 1 - RULES FOR THE ADMINISTRATION OF THE OREGON SAFE EMPLOYMENT ACT
Appendix B - Instructions for Computing Lost Workday Case Incident Rates (LWDCIR) for an Individual Firm

Incidence rates for an individual establishment or firm may be calculated by employers by using the same formula used to calculate industry-wide incidence rates from the annual Occupational Injury and Illness Survey. An employer may then compare her/his own work injury and illness experience to the overall experience in her/his industry in Oregon or the nation.

The formula requires:

(a) the number of lost workday cases, and

(b) the number of hours actually worked by all employees during the reference period. To produce an overall incidence rate:

(a) Determine the number of lost workday cases by adding the totals for columns 2 and 9 of the Occupational Injuries and Illnesses Log (OSHA No. 200).

(b) Total the number of hours actually worked during the year by all employees from payroll or other time records. The hours worked figure should not include any non-work time even though paid, such as vacations, sick leave, holidays, etc. (If actual hours worked are not available for employees paid on commission, salary, by the mile, etc., hours worked may be estimated on the basis of scheduled hours or 8 hours per workday.) The formula for computing the incidence rate is as follows:

(a) Number of lost workday cases x 200,000 = lost workday employee hours worked.

(b) Case Incidence Rate: This rate represents the number of lost workday cases occurring per 200,000 hours of work exposure or 100 full-time equivalent workers. The same base is used in computing the occupational injury and illness rates for Oregon and for the nation.