Confined Space Training: Signs and Symptoms of Exposure

The rules that deal with confined space training are clear. Entrants and attendants may need to know a lot about medical issues.  (This is one of many issues we discuss in our Confined Space Train the Trainer classes).

OSHA's Permit-required Confined Space Standard lays it out in detail:

(h) Duties of Authorized Entrants - The employer shall ensure that all authorized entrants: (1) Know the hazards that may be faced during entry, including information on the mode, signs or symptoms, and consequences of the exposure;

Attendants need that knowledge along with being aware of "possible behavioral effects of hazard exposure in authorized entrants." [1910.146 (i)(2)]

Student learning all the signs and symptoms of hazard exposure

Learning all the signs and symptoms of hazard exposure can be challenging.

For a trainer that can be a challenge.  While it's easy to read through a list of signs and symptoms on a PowerPoint slide, how can you ensure that your entrants and attendants actually know this information? Will they be able to recall it if needed?

Safety Data Sheets: Limitations

Reviewing Safety Data Sheets before entry helps. But we would only have these for products and residues in the space or materials used for cleaning. There are a number of possible confined space hazards like oxygen deficiency, heat/cold, and byproducts of reactions (e.g., carbon dioxide and methane) that won't have SDSs. How can we ensure that our entrants and attendants will know (and respond to) signs and symptoms of these hazards?

The answer, we believe, can be found by considering the intent of these confined space training rules in the standard. Specifically, OSHA inserted these requirements for one reason. They wanted to ensure that entrants were able to recognize the hazard at its onset and perform a self-rescue. This is an essential aspect of ensuring entrant safety by requiring this in confined space training programs. But is there another way of dealing with this? We think so.

Another Key Piece of Knowledge

While training entrants and attendants to recognize signs and symptoms of exposure is still an important aspect of our programs, we also provide our students with another key piece of knowledge. We simply tell them that if they ever feel discomfort in a confined space for any reason they should inform the attendant (and their co-workers) and exit the space. We take this approach because it is the easiest way to fulfill the intent of that section of the standard. It also covers conditions that standard doesn't directly address like underlying medical conditions (high blood pressure, diabetes, etc.) and elevation issues.

Example: Elevation and Oxygen Deficiency

Take the example of a contract tank cleaning crew based in San Diego who fly up to Laramie, Wyoming for a job. They step off the plane and they are in an atmosphere with 20.9% oxygen, but the air pressure (with oxygen comprising about 20% of that air pressure) is much lower. Because the air pressure is lower, the oxygen available to them is equivalent to an oxygen level of 16% at sea level. So they are effectively oxygen deficient when they arrive at work the next day.

For the younger, fitter crew members, this may not be an issue. But for others it can be which is why we want them to evacuate the space when they feel the symptoms and figure out what's going on once they are outside the tank. A similar situation can arise with heat exposure given that it can effect people differently based on their pre-existing conditions (another topic we address in class).

Add to this the fact that heat, oxygen deficiency, and other hazards often share signs and symptoms and it's easy to see how entrants can be confused regarding these issues.

So as a trainer you definitely want to review signs and symptoms but if you summarize these by stressing the adage: "When in doubt, get out!" you will be on firm footing with respect to meeting the intent of this confined space training requirement.




Jim Johnson September 6, 2017

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