Page 48 - OHS, May 2021

TRAINING: CONFINED SPACES
Clearing the Air on Confined Space Ventilation
To help clear the air, here is some advice for selecting a proper ventilation blower for a confined space, as well as some tips on usage.
BY JAN WIENCZKOWSKI
For all of the attention that confined spaces receive, many safety managers are still uncertain about ventilation requirements. They may not understand how much airflow is needed to properly ventilate a given space. They may
overlook ventilation principles allowing them to eliminate pockets of bad air or dead spots where workers are positioned, or they may fail to monitor air quality before and during employee entry into a confined space. To help clear the air on this subject, here is some advice for selecting a proper ventilation blower for a confined space, as well as some tips on proper usage.
Know Your Space
First, it is necessary to understand what defines a confined space. A confined space is not designed for continuous worker occupancy but is large enough for a worker to be able to enter and perform work. It also has limited or restricted means for entry or exit.
Common examples of confined spaces include tanks, vessels, silos, storage bins, hoppers, vaults, pits, manholes, tunnels, equipment housings, ductwork and pipelines.
A confined space may have natural ventilation, but it may not be sufficient enough to provide the proper working atmosphere. A confined space may have no ventilation at all. In both instances, forced air ventilation may be required. A confined space also isn’t necessarily small; on the contrary, it can be quite large. Several factors may contribute to defining a space as confined, so having a thorough understanding of OSHA regulations is the best way to determine if a particular space qualifies.
Hazardous or Non-Hazardous?
A confined space will be one of two types: hazardous or non- hazardous. Any area where the possibility of fire or explosion may exist due to the presence of flammable material is what the
44 Occupational Health & Safety | MAY 2021
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Photo Courtesy of Wienczkowski