Dealing With Confined Space A Complicated Challenge

By Jeff Griffin, Senior Editor | April 2014, Vol. 69 No. 4

There are several fallacious assumptions involved. “The first is that the employee will do nothing that would cause their head to break the plane of the excavation and expose themselves to gases below natural grade. The second is that the gases will be heavier than air and not pressurized or stirred by wind to cause them to rise and overcome the employee. Insofar as gas distribution employees have been overcome and killed in excavations 12-inches deep, it is clear that the excavation standard leaves much to be desired where hazardous atmospheres are involved.

“Likewise, the failure to discuss UFL (upper flammable limit) and backdraft situations, which might be encountered from flammable liquids in excavations or from leaking containers in a storage shed that could lead to problems.

“Finally, workers who believe themselves safe with an oxygen level of 19.5 percent may not realize that the level may drop if they do something like ignite a cutting torch. Or it could be an indication of the infiltration of another gas that may create an asphyxiation situation, or a toxicity situation of a poisonous kind that the monitor cannot detect, particularly if the infiltration continues during the work.

“To understand the nature and generation of confined space scenarios and how to recognize and deal with them, employees should be educated via this shopping cart full of standards. Then deadly myths, such as “clean and dry means safe’ and others, can be dispelled.”

Evaluation

Armed with education and information, workers should be better able to recognize and evaluate potential hazards when working in confined spaces.

Prior to engaging in the work in a confined space, employees, particularly those designated as competent persons, supervisors or attendants should evaluate the site and ask themselves these questions:

• Where are the places a hazardous atmosphere could exist or an engulfment occur?
• How could the atmosphere be generated?
• Could the soil do it from previous contamination by spills or leaks?
• Could we be digging in a landfill? Are there underground utilities or storage tanks that could leak into the excavation?
• Have all valves controlling the influx of water or other liquids been locked and tagged out?
• Is nearby traffic generating carbon monoxide?
• Are we generating carbon monoxide with chop saws, tampers, or other equipment?