The Hierarchy of Controls: A General Strategy for Injury Prevention

Today’s post is going to be more theoretical than usual, but I’d like to share a quick summary of the overall approach to injury prevention that is used in engineering, public health, manufacturing and other industries.  It’s called the hierarchy of controls.  I’m sharing it because for me, it’s been a useful way to think about injury prevention, and because a lot of the specific prevention strategies I’m posting were made with this hierarchy in mind.

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The hierarchy of controls ranks different ways of dealing with a hazard from most effective to least effective.

The most effective way of addressing a hazard is to eliminate it it completely.  If the hazard is gone, no one can get hurt by it.  One example I can think of from my own experience is when we got rid of a bull that was starting to charge at whoever was feeding him.

Getting rid of a hazard isn’t always a reasonable solution. The next best thing is substitution, or replacing something that is more hazardous with something that is less hazardous.  For example, substituting a tractor with ROPS for one without greatly reduces the risk for many jobs.

If substitution isn’t possible either, the third option is engineering controls, or coming up with designs that limit a person’s interaction with the hazard. The special equipment used for storing and applying anhydrous ammonia are good examples of engineering controls.

If it’s not possible to eliminate, substitute, or engineer away the hazard, the next level of defense is administrative controls.  These are things like laws, or rules that you have on your own farm.  Administrative controls aren’t very effective because the person has to decide whether to follow the rules or not.

The least effective way of dealing with a hazard is personal protective equipment, such as dust masks, gloves, goggles, steel toed boots, earplugs, etc. Protective equipment is considered the least effective for a few reasons. Like with administrative controls, people have to decide to decide to use the equipment. For protective equipment to work, it has to be the right type for the job and it must be worn correctly (this is more difficult than you’d think). Protective equipment can  make jobs more difficult or create new hazards if it makes it difficult to move, hear, see, or if they can get tangled in other equipment.  That’s not to say that you shouldn’t wear protective equipment, but it should be a backup plan or extra protection instead of your main strategy for avoiding injury.

I hope that  this general overview of the hierarchy of controls was useful. For me it’s been a helpful way to think about injury prevention.  If you’d like to learn about injury prevention strategies in more detail, here is a link to the Department of Labor’s guide to injury prevention:

Department of Labor Injury Prevention Guide