If you’re in the health and safety field, you have undoubtedly seen the figure below illustrating OSHA’s three lines of defense against workplace hazards. 
Source: OSHA
In this article, we’ll review the three lines of defense -- engineering controls, administrative and work practice controls, and personal protective equipment (PPE) -- and discuss how housekeeping fits into the picture.OSHA’s three lines of defense
For any workplace hazard, from musculoskeletal disorder (MSD) to silica dust, OSHA relies on the three lines of defense philosophy. The idea is to start at the top with the most effective solutions and then work your way down. In general, the solutions lower down the pyramid should be considered supplementary to, not replacements for, the ones higher up. The examples below are from OSHA’s silica dust control measures page.Engineering controls
At the top of the pyramid sits engineering controls. OSHA defines engineering controls as physical changes to the workplace that eliminate or reduce the hazard in question. These are the first lines of defense. Here are some of the recommended engineering controls for silica dust hazards:- Local exhaust ventilation (LEV)
- Containment methods, such as blast-cleaning machines and cabinets
- Wet sawing or wet drilling of silica-containing materials
Administrative and work practice controls
This second line of defense focuses on processes and procedures that reduce the severity, duration, and frequency of exposure to risk. Examples of administrative and work practice controls for silica dust:- Limiting workers’ exposure time
- Requiring workers to shower and change clothes before leaving the worksite
Personal protective equipment
At the bottom of the pyramid is PPE, which includes protective wear like glasses, gloves, masks, and respirators. PPE is the least effective line of defense, and in most cases it should not be used on its own or as a substitute for engineering controls or administrative and work practice controls. For silica dust, OSHA specifies that PPE should be considered a temporary control and only be used when the other approaches aren’t sufficient to keep dust levels below the permissible exposure limit.Where does housekeeping fit in?
Housekeeping is an administrative and work practice control. Though not a replacement for engineering controls when they apply, proper housekeeping is a powerful and essential line of defense against many types of workplace hazards, from silica and combustible dust to slips, trips, and falls. Housekeeping is such an important defense that it’s incorporated into many OSHA standards, as well as other standards that OSHA relies on heavily during inspections, like NFPA 652 for combustible dust. Essentially, no matter what area of industrial processing you operate in, you need a solid housekeeping program to keep your workers safe and stay compliant with current regulations._________________________
The best way you can avoid being cited by OSHA for non-compliance is to implement these three lines of defense according to the hierarchy. First, implement any feasible engineering controls. Then, develop processes and procedures, like housekeeping, to supplement engineering controls. Finally, use PPE as an extra layer of worker protection. Have questions about using OSHA’s three lines of defense to fight dust-related hazards in your facility? Give us a call or send us an email. We’d be happy to help!
