As most, sadly not all, safety professionals will attest to, there is a hierachy of four (4) controls we use to manage risks: 1) Substitution/Elimination, 2) Engineering Controls, 3) Administrative Controls, and 4) Personal Protective Equipment. In process safety environments, the hazards are often times so great that ALL FOUR layers may be needed. What do I mean?
There is one thing that all of the OSHA Highly Hazardous Chemicals and EPA’s Extremely Hazardous Substances have in common… they deserve our RESPECT! By this I mean we need to use all of our available tools to ensure our workers remain safe while work with and/or around these Highly Hazardous Chemicals and Extremely Hazardous Substances. This means that we may have to use three of the four controls or just the single control of Elimination/Substitution.
First lets discuss the four (4) controls.
Elimination and substitution, while most effective at reducing hazards, also tends to be the most difficult to implement in an existing process. If the process is still at the design or development stage, elimination and substitution of hazardous materials may be inexpensive and simple to implement. For an existing process, major changes in equipment and procedures may be required to eliminate or substitute a hazardous material.
Engineering controls are used to remove a hazard or place a barrier between the worker and the hazard. Well-designed engineering controls can be highly effective in protecting workers and will typically be INDEPENDENT of worker interactions to provide a high level of protection. The initial cost of engineering controls can be higher than the cost of administrative controls and/or personal protective equipment (PPE), but over the longer term, operating costs are frequently lower, and in some instances, can provide a cost savings in other areas of the process. Engineering controls a hazard by such means as isolating the hazard or by ventilating the workspace. Engineering controls are the most reliable and effective controls, other than Elimination/Substitution.
Protective Safety Devices are not considered to be an “engineering control” by some professionals (although I personally group them as engineering controls). Although possibly not as reliable as true engineering controls, such methods include interlocks, redundancy, failsafe design, system protection, energy isolation devices, fire suppression.
Administrative controls significantly limit daily exposure to hazards by control or manipulation of the work schedule or work practices/habits. Job rotation is a type of administrative control. Administrative controls and personal protective equipment (PPE) are frequently used with existing processes where hazards are not particularly well controlled. Administrative controls and PPE programs may be relatively inexpensive to establish but, over the long term, can be very costly to sustain. These methods for protecting workers have also proven to be less effective than other measures, requiring significant effort by the affected workers. Procedures and training are also considered an administrative control. These controls include hazard control programs (OSHA compliance requirements, (i.e., OSHA Standard Requirements: Hazard Communication, Lockout/Tagout, Bloodborne Pathogens, Fall Protection, Confined Spaces, Trenching and Excavation, Material Handling Equipment, Electrical, Process Safety Management, Machine Guarding, etc.) workplace rules, safe and healthful work practices, personal hygiene, housekeeping and maintenance, and procedures for specific operations.
PPE to be used are determined by hazards identified in hazard analysis. PPE should ONLY be used when ALL other hazard controls have been exhausted or more significant hazard controls are not FEASIBLE. (CLICK HERE to see OSHA’s official defintion of “feasible” and how it applies to workplace safety).
So lets examine how these controls can be applied in HIGH RISK TASKS such as non-routine line/process opening.