Safety Tidbit 3.01 – Hierarchy of Controls
Reference(s):
Doney, B. C., Groce, D. W., Campbell, D. L., Greskevitch, M. F., Hoffman, W. A., Middendorf, P. J., … Bang, K. M. (2005). A Survey of Private Sector Respirator Use in the United States: An Overview of Findings. Journal of Occupational and Environmental Hygiene, 2(5), 267–276. https://doi.org/10.1080/15459620590949020
How many of you, when you are starting to research a concept or idea, started your search with Wikipedia or Google? I’m sure many of us do and I did just that for this week’s Safety Tidbit. I put in the keywords “Hierarchy of Controls” in the Google search engine and the first entry was from Wikipedia and more specifically Wikipedia referenced NIOSH, nice!!! Wikipedia defines hierarchy of control as a system used in industry to minimize or eliminate exposure to hazards. Graphically depicted by the National Institute for Occupational Safety and Health at the Centers for Disease Control.
Elimination – if hazard is physically removed there is no way for workers to be exposed.
Substitution – is similar in nature to elimination however the original hazard is replaced by something different. Once substituted the hazard assessment process must start over. Hopefully, the substitution is less hazardous than that of the original hazard.
Engineering Controls – controlling the generation of the hazard at its point of generation so it cannot expose the worker. The ultimate engineering control isolates the hazardous operation completely from the worker. Although control of airborne contaminants is commonly accomplished through local exhaust ventilation. However, for dust hazards, wetting is a most effective control.
Administrative Controls – Controlling exposures administratively commonly involves worker rotation so as to shorten their duration of exposure. It could take the form of the practice of vacuuming debris versus dry sweeping or having the worker leave the work area when possible so reduce the total time of exposure. Also, remember many administrative controls are only as good as the training and adherence to the process or management. So, if the process is burdensome or inconvenient to follow workers will move to what is easier to do.
Personal Protective Equipment – Is the last line of defense. No modification to the work environment has been made and the only barrier to exposure exists from the proper use of the personal protective equipment (PPE). Examples of PPE include respirators, gloves, safety glasses, coveralls. Similar to administrative controls above, the main limitation is the human element which is even more pronounced with PPE. The individual use of any PPE is only as good as the training on how to properly use the gear, the diligence with which it is employed, and the supervision to monitor both. Interestingly, of the approximately 1,600 workplaces surveyed that required use of respiratory protection over 90% had at least one indicator of an inadequate respiratory protection program. (Doney et al., 2005)
Hope this was helpful and thanks for reading my Safety Tidbits! Comments and questions are always welcome. ~ ABS
P.S. If you have an interesting safety or health question please let me know.
