Cleaners’ Occupational Injury Reduction Emphasis (CORE)

The Cleaners’ Occupational Injury Reduction Emphasis (CORE) research project started as the Washington State Janitorial Workload study, which was a research project in the Safety and Health Assessment and Research for Prevention (SHARP) program.

We were tasked by the Washington State Legislature to identify workload issues and risk factors that might contribute to the high rates of work-related injury and illness in janitors, and to develop usable tools to reduce these risks, like the workload calculator (now available in preliminary form for testing).

During the initial four years, we conducted focus groups, one-on-one interviews, statewide surveys of janitors and janitorial employers, and detailed worksite observations of janitors. We also created the workload calculator tool.

Currently our program aims to:

  • Expand the janitorial workload calculator tool, including releasing a web-based version and a user manual
  • Continue to conduct detailed worksite observations, to expand and refine the calculator. Workload assessments are completed by watching janitors as they do their work, asking them a few questions about their job and taking a few measurements (e.g., weights of vacuums, and garbage cans). Participation is voluntary. Decisions janitors and custodians make about participating will not affect any legal case or workers’ compensation claim they may have. No janitor or custodian is required to participate. We will not share names or personal information with anyone outside the research team, and none of the individual information will be shared with employers.
  • Evaluate tools and cleaning methods to determine how they influence the risk for injury.
  • Continue to interview injured janitors to identify root causes of common injuries and illnesses. If you are a Janitor or Custodian who has been injured on the job in Washington State and filed a workers’ compensation claim, you may receive a letter from us asking if we can conduct a brief telephone interview with you about your work and injury experience. The details that you can provide can help us identify hazards and create prevention materials.
  • Create prevention & intervention tools to help keep janitors safe and working.

Want to try out the workload calculator, or have feedback on the tool? Would you like your worksite considered for a possible visit? Any other questions or concerns that we should know about? Contact us!

For more information:

Workload Calculator

The Janitorial Workload Calculator

One of the main goals of our janitorial research was to create a useable workload calculator tool. We developed the calculator to support employers, worker representatives, and community partners in the prevention of injuries through the identification and quantification of risk. Ultimately, we want to improve janitors’ working conditions, by providing a tool that can evaluate workload.

A detailed reference guide will be released soon.

The calculator is intended to:

  • Assess janitorial work performed in large commercial office buildings.
  • Evaluate the risk at the job level, not the task level.
  • Assess the risk to the back, shoulder, and hand/wrist.

What the calculator can do:

  • Measure the workload based on the strain that janitorial work tasks place on janitors’ bodies.
  • Assist managers and work schedule planners of commercial janitorial services firms as they plan their work schedule, to help allocate workers.
  • Assist community partners in evaluating jobs for the janitors they represent.
  • Provide an additional tool to complement existing injury prevention efforts and programs to reduce work-related musculoskeletal disorders.

We created the calculator for three primary types of users:

  1. A manager/supervisor designing and scheduling a new janitorial job.
  2. A manager/supervisor who would like to evaluate the workload of an existing janitorial job.
  3. An environmental health and safety professional or practitioner who is conducting a job risk evaluation.

How does it work?

Users can enter data on task, tools, and the parameters of the job in question. The calculator combines these input observations with known risk factors (determined by measurements taken on real janitorial jobs during calculator development) to determine an exposure risk level for the workload.

The calculator assesses musculoskeletal workload from repetitive motions, awkward postures and forceful hand exertion, and cardiovascular workload. It does not assess risk of injury from chemical exposures, slips/trips/falls and organizational factors. The calculator also does not predict the development of injuries, provide recommendations, nor determine risk based on individual worker demographics.

The calculator focuses on three elements of janitorial work that may contribute to the risk of injury:

  1. The cleaning task being performed.
  2. The location that is being cleaned.
  3. The tools, technology and methods being employed.

For more information:

The workload calculator is currently available for pilot testing, as an excel program. We are in the process of developing a web-based calculator and a user guide. For more information, or if you are interested in piloting this calculator, please contact Dr. Stephen Bao: baos235@lni.wa.gov


Legislative Reports

2023 Washington State Janitorial Workload Study: Progress Report to the Legislature

December 2022 Washington State Janitorial Workload Study: Progress report to the Legislature

Appendix A: Workload Calculator Reference Guide

January 2022 Washington State Janitorial Workload Study: Progress report to the Legislature

June 2020 Washington State Janitorial Workload Study: Progress report to the Legislature

Appendix A: Focus Group Report

Appendix B: Mistreatment of janitorial workers: A hidden health and safety issue

Appendix C: Economic Scan of the Janitorial Services Industry in Washington State


Spring 2024 - English

Fall/Winter 2023 - English

July 2022 - English

February 2022 - English

March 2021 - English

August 2020 - English

May 2020 - English

June 2019 - English

Journal Articles

Lee W, Lin JH, Howard N, Bao S (2023). Physiological responses, trunk posture, and work pace in commercial building cleaning in Washington State: An observational field study. Journal of Safety Research, 86. doi.org/10.1016/j.jsr.2023.05.013.

Anderson NJ, Smith CK, Foley MP (2022). Work-related injury burden, workers' compensation claim filing, and barriers: Results from a statewide survey of janitors. American Journal of Industrial Medicine, 65(3). doi.org/10.1002/ajim.23319.

Lee, W, Lin, JH, Howard, N, Bao, S (2022). Methods for measuring physical workload among commercial cleaners: A scoping review. International Journal of Industrial Ergonomics. doi.org/10.1016/j.ergon.2022.103319.

Lin, J.-H., Shin, G., & Gerberich, S. G. (2022). Safety, Health, and Ergonomics in Cleaning Occupations. Applied Ergonomics, 106, doi.org/10.1016/j.apergo.2022.103914.

Lin, J.-H., Lee, W. Smith, C. K., Yragui, N. L., Foley, M. and Shin, G. (2022). Cleaning in the 21st Century: The musculoskeletal disorders associated with the centuries-old occupation. Applied Ergonomics, 105, doi.org/10.1016/j.apergo.2022.103839.

Lee, W. Yragui, N. L., Anderson, N. J., Howard, N., Lin, J.-H., and Bao, S. (2022). The job demand-control-support model and work-related musculoskeletal complaints in daytime and nighttime janitors: The mediating effect of burnout. Applied Ergonomics, 105, doi.org/10.1016/j.apergo.2022.103836.

Previous research from SHARP regarding janitors:

Prevention Resources

COVID 19 Publications

Protect Yourself at Work: How to Clean and Disinfect for COVID-19 (Coronavirus) (English)

How to wear and use a homemade mask (English)

Janitorial Safety Tip Sheet - Protect Your Health (English) 

Janitorial Safety Tip Sheet - Hand Washing (English)

Janitorial Safety Tip Sheet - Employers (English)  Spanish

Tip sheets

Unlabeled chemicals can be dangerous!

Watch Out for Hidden Dangers! - Needlestick injuries

How to be an Active Listener

What is Safety Leadership?

Janitor Safety Tip Sheet 1 - English