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The Safety Brief In our podcasts we give short but valuable overviews
and insights into how contractors and safety managers
can be even more effective in protecting their workers.
In our podcasts we give short but valuable overviews and insights into how contractors and safety managers can be even more effective in protecting their workers.

Confined Spaces with Hazardous Atmospheres

Confined spaces need a portable gas monitor if there is a chance of low oxygen, high carbon monoxide, or other hazardous atmospheres. Hear about a bump test.

A confined space with a hazard, or potential hazard, is called a permit-required confined space. One of those hazards is a hazardous atmosphere. In this podcast, Dan Clark explains how the air a worker breathes needs to be monitored.

Portable gas monitors are highly sensitive and can detect high levels of carbon monoxide, hydrogen sulfate, and other toxic gases. They can also detect low oxygen levels. Hear about best practices when using these important instruments.


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Dan Clark: Confined spaces plus hazardous atmospheres create a double whammy called PRCS, or permit-required confined spaces. Portable gas monitors are designed just for them. Let’s look into them next.

Hello, I’m Dan Clark of The Safety Brief, tackling health and safety hazards in today’s demanding industrial and construction worksites, compliments of Creative Safety Supply.

Confined spaces are a current topic in the world of safety. The new Confined Spaces in Construction standard when into effect on August 3rd. OSHA delayed full enforcement for residential construction again, now a second time, until January 8, 2016. But this doesn’t mean job sites are immune from confined spaces safety. In both the General Industry and the new Construction standard, employers must have a system to alert workers of hazardous atmospheres in confined spaces.

You want a portable gas monitor in these permit-required confined spaces.

Examples of hazardous atmospheres:

• Carbon monoxide
• Low oxygen
• Hydrogen sulfide

You can’t really rely on smell, as some gases don’t have an odor. Here’s an example: Hydrogen sulfide smells like rotten eggs at low concentrations but when there’s a lot of it, it paralyzes the sense of smell so people don’t notice it. This can be a problem for sewer workers.

Gas detection best practices:

1. Use a direct-reading portable gas monitor.

2. Test the monitor daily before use by exposing it to a gas that will set off all of its alarms. This is called a bump test or calibration check.

3. If the gas monitor fails a bump test, perform a full calibration according to the manufacturer instructions.

4. If the monitor is fine, test the atmosphere prior to entering a space. Because some gases weigh more than others and can settle in the bottom of a space, be sure the air where the entrant will be working is tested.

5. Test continually while work is performed. Some monitors can be worn by the worker.

6. When the space is vacated, perform a re-entry test before entering again.


And finally, don’t forget the basics of confined spaces. Companies must have plans for confined space entry and three people must be involved.

1. The entrant, the person who performs the work.

2. The attendant, the person who stands nearby in contact with the entrant.

3. The supervisor, who oversees work performed.

That’s all for this episode, Confined Spaces with Hazardous Atmospheres. Come back for more ways to stay safety compliant in today’s ever-changing landscape of safety requirements. I’m Dan Clark of The Safety Brief, a service of Creative Safety Supply. Save 10 percent off your entire order at with coupon code BIG10.


Portable gas monitor image by U.S. Dept. Of Labor / OSHA / Roy Berke; welding photo 2012 by PEO ACWA / U.S. Army; Turbine worker image by the U.S. Dept. Of Energy

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