September 30, 2019




AMANDA EDENS, Acting Deputy Assistant Secretary
Office of the Assistant Secretary


PATRICK J. KAPUST, Acting Director
Directorate of Enforcement Programs

Revisions to the Occupational Safety and Health Administration (OSHA) Weighting System

This memo describes the new OSHA Weighting System (OWS) that replaces the Enforcement Weighting System (EWS). The new OWS accomplishes two objectives: 1) to further encourage the appropriate allocation of resources to support OSHA’s balanced approach promoting safe and healthy workplaces, and: 2) to continue to develop and support a management system to focus enforcement activities on critical and strategic areas where the agency’s efforts can have the most impact. OWS is framed around three enforcement activities of resource use: enforcement, essential enforcement support functions, and compliance assistance.

As you know, inspections are the fundamental tool that OSHA uses to ensure employers comply with its standards, comply with the general duty clause, and abate workplace hazards. OSHA recognizes that all inspections are important and this focus will not change under the new OWS. Inspection protocols also will not change under the new OWS. Consistent with the Field Operations Manual, Area Offices must fully meet their responsibilities under the Occupational Safety and Health Act, including responding to unprogrammed activity such as imminent dangers, fatality/catastrophe, complaints/referrals, and severe injury reports, as well as performing planned inspection activity. All inspections will fully and fairly enforce the law.

Historically, OSHA used the number of completed inspections as a primary metric to measure enforcement activity. While this metric served a useful purpose, it created an unintended incentive to complete less demanding inspections rather than those requiring a greater amount of field resources. In 2015, OSHA initiated a system that weighted certain inspections depending on the time taken to complete them (e.g., fatality inspections) or, in some cases, their impact on workplace safety and health (e.g., workplace violence or heat inspections). The EWS experience suggests that time is not the only major factor to assess when considering the impact of an inspection. Other factors such as types of hazards inspected, abated hazards, and effective targeting influence the impact on safety and health in the workplace.

As a result of the agency’s experience, OSHA is initiating a new weighting system for fiscal year (FY) 2020. The system will continue to weight inspections, but will do so based on a number of new factors, including the impact of the inspections and the agency’s priorities, rather than simply on a time-weighted basis. The updated OWS approach recognizes a greater percentage of the overall work performed by the field—inspections organized in strategic categories, essential enforcement support functions, and compliance assistance efforts.

The new OWS enforcement activity underscores the importance of complex enforcement activity focused on the most hazardous workplaces and operations. Examples include process safety management, combustible dust hazards, and fatality/catastrophe cases. In addition, OWS includes weighting for OSHA’s “focus four” hazards—those areas where many fatalities occur (e.g., falls, and struck-by hazards). The original enforcement unit (EU) equation will calculate the base weight for a given category, and then an OWS weight factor will be applied to reach the desired value or impact of the inspection activity that directly supports OSHA’s yearly Operation Plan and hence the Department’s FY 2018-2022 Strategic Plan, Strategic Goal 3, Promote Safe Jobs and Fair Workplaces for All Americans, and OSHA’s Strategic Objective 2.1, Secure Safe and Healthful Working Conditions for America’s Workers. See the attached whitepaper Revisions to the OSHA Weighting System for information on all weighted categories.

The OWS enforcement activity assigns an EU value to specific categories of inspections. All inspections receive at least one EU; however, the following groups and sub-categories receive more EUs:

  1. Group A: Includes the most time intensive, complex, and high-priority inspections. 7 EUs
    1. Criminal cases
    2. Significant cases
  2. Group B: Includes inspections for high-priority hazards and those that are more complex than average and/or are of high lasting value. 5 EUs
    1. Inspections following fatalities and catastrophes
    2. Chemical plant NEP and Process Safety Management (PSM) covered inspections
  3. Group C: Includes programmed inspections following an established emphasis program (EP) for hazards that are among the leading causes of death in the workplace. 3 EUs
    1. Caught-in hazards—e.g., trenching, equipment operations, oil & gas
    2. Electrical hazards—e.g., overhead power lines, electrical wiring methods
    3. Fall hazards—e.g., scaffolds, elevated walking working surfaces
    4. Struck-by hazards—e.g., highway work zones, landscaping, material handling
  4. Group D: Includes programmed inspections following an established EP for priority hazards that are somewhat time intensive and are a high priority. This category also includes inspections for novel hazards and programmed inspections undertaken in conjunction with an established enforcement policy addressing associated serious safety and health hazards. 2 EUs.
    1. Amputation hazards
    2. Combustible dust
    3. Ergonomics
    4. Federal agency inspections
    5. Heat hazards
    6. Non-PEL overexposures
    7. Workplace violence hazards
    8. Permit required confined space hazards—e.g., grain storage or maritime or construction
    9. Personal sampling—e.g., air contaminants or noise
    10. Site specific targeting
  5. Group E: Includes all other inspections not otherwise listed. 1 EU

  6. Regions may submit other regional or local emphasis programs for approval and weighting if they are not already covered under items 1-4 and assign them two to three EUs.

OSHA Weighting System

The OWS enforcement activity has been in testing and running in parallel with the EWS since FY 2017. OSHA will continue to operate the new OWS enforcement activity in parallel with the EWS. In addition, the agency will initiate the OWS essential enforcement support function activity to capture rapid response investigations and phone/fax investigations. Full implementation of the new OWS enforcement activity begins in FY 2020. The agency recognizes that considerable development is necessary to fully implement OWS activity for essential enforcement support functions and compliance assistance during the next few fiscal years.

Operating the EWS and OWS in parallel ensures full information gathering and coding of all weighted activities. This approach also allows for year-to-year comparison of the data and an opportunity to assess the impact on other program areas such as the severe injury reporting system. If you have any questions, please contact Lewis Daniel in the Office of Chemical Process Safety and Enforcement Initiatives at or (678) 237-0433.