I recently came across an excellent youtube video. While the video appears to be about five years old, and was made in Arizona, the incident it portrays could have happened anywhere, any time, including here in Minnesota.
The video is, in part, a recreation of an incident which was responded to by the Phoenix Fire Department. Many fire departments use videos like this as a safety training tool for their staff. The incident portrayed in the video involved a pregnant employee at an area McDonalds who was overcome by a then-unknown agent. The employee had gone to the basement of the restaurant but when she ascended the stairs back to the main level, she couldn’t stand or speak. When emergency responders went into the basement to investigate what might have happened, they too were overcome, by what turned out to be Carbon Dioxide leaking from the soft drink dispensing system. Carbon Dioxide is much heavier than air, so during a leak, it settles in low-lying areas (the basement), and begins to displace Oxygen. Oxygen levels were later measured at 17.5% (20.9% is normal).
You can view the video here. It’s quite long and perhaps overly-detailed, but well done.
While a basement isn’t usually considered a permit-required confined space, the hazards of Carbon Dioxide and other asphyxiants are the same regardless of setting.
If your facility has permit-required confined spaces, there are several things you must do to protect employees and others:
- You must identify, evaluate, and classify all permit-required confined spaces. This is a critical first step. I strongly encourage you to work with a qualified safety consultant who is very familiar with the OSHA regulation and technical aspects of confined space entry. I strongly recommend making a written inventory of all spaces you evaluated, and your findings.
- Determine who, if anyone, will be permitted to enter these spaces (Employees? Contractors? Nobody?)
- Restrict access by unauthorized persons by posting signs, and securing the spaces.
- Develop a permit system for entry.
- Most importantly, provide in-depth safety training for your employees, regardless of whether or not they enter. If your employees will enter and work in permit-required confined spaces, they must receive safety training on all foreseeable hazards, including the types of gases and other atmospheric hazards that might be present, and how to monitor, and ventilate the space before and during entry. Safety training must be specific to the anticipated hazards, so you should discuss how hazards such as Carbon Dioxide are created, where they might be found, their hazards, and signs and symptoms of exposure. Again, the services of a qualified safety consultant will be key here, especially someone who has expertise in OSHA safety training. Proper safety consulting will be critical.
- Provide the proper types of equipment for entry, such as gas meters which measure Oxygen content, explosive/flammable gases and vapors, and toxic substances. Ventilation equipment will most likely be required, as will retrieval equipment.
One last note, in my safety consulting experience, I am shocked to see the number of employers who are still using the old MN confined space entry rules for general industry. This regulation was repealed well over a decade ago. MN OSHA now enforces the Federal confined space regulation for confined space entry (29 CFR 1910.146).