Safety Tidbit #40 – Hazardous Atmospheres and Entry into the PRCS

Safety Tidbit #40 – Hazardous Atmospheres and Entry into the PRCS

I recently had a client that brewed limited runs of specialty beers for themed events (I know tough duty!).  However, as a health and safety professional, I have to focus on the hazards.  For instance, the brewer must clean out the primary fermentation vat at the end of each batch. The fermentation vat contains an access port at the bottom he uses to clear out all solids before running a sanitizing solution through it. During fermentation, the vat is sealed and oxygen removed and carbon dioxide are monitored to ensure proper fermentation.

First, is this a confined space?  OSHA defines a confined space as a space that:

- Is large enough and so configured that an employee can bodily enter and perform assigned work; and

- Has limited or restricted means for entry or exit (for example, tanks, vessels, silos, storage bins, hoppers, vaults, and pits are spaces that may have limited means of entry.); and

- Is not designed for continuous employee occupancy.

I think we can all agree that the vat meets the definition of a confined space. And, based on a 1999 OSHA Letter of Interpretation, entry means all extremities as well has head and torso.  Now, is the confined space a permit-required confined space? Again, OSHA defines a permit-required confined space to be a confined space that has one or more of the following characteristics:

- Contains or has a potential to contain a hazardous atmosphere;

- Contains a material that has the potential for engulfing an entrant;

- Has an internal configuration such that an entrant could be trapped or asphyxiated by inwardly converging walls or by a floor which slopes downward and tapers to a smaller cross-section; or

- Contains any other recognized serious safety or health hazard.

Well, given the anoxic environment in the vat, it definitely contains a hazardous atmosphere. So, the vat is a permit-required confined space. 

Theoretically, the brewer is only required to put his hands and arms into the vat and should only meet the very minimal definition of entry. However, it is natural that at any given time the brewer might want to pop his head inside the vat to inspect the cleanliness of the vat.  But, does the employer need to create a complete permit entry program? If the only hazard in the vat is the hazardous atmosphere and forced air ventilation alone can maintain the vat safe for entry, then the complete program need not be created [1910.146(c)(5)(i)].  Ultimately, the employer must develop monitoring and inspection data that supports the demonstrations that the space is safe for occupancy using forced-air ventilation.

I hope this was informative.  Thanks for reading! Please share my blog with others.