Navigating OSHA's Sweep Auger Interpretation

Confused and frustrated. Two words to best describe the state of the grain industry since the release of the Occupational Safety and Health Administration’s Sweep Auger Letter of Interpretation.

The issue began when an insurance agent contacted OSHA requesting clarification on the restrictions involved with employees working in bins while sweep augers are in operation.

Here are the facts as stated in the agent’s letter: 1) A sweep auger is a portable unguarded screw auger attached to a pivot that circles the perimeter of the storage bin and conveys grain into a center sump(s) located in the bin floor; 2) Grain handling facilities rely on sweep augers to clear bins; 3) In order for a sweep auger to work properly, in most cases, an operator must regularly make adjustments to the device inside the bin; and 4) By design, a sweep auger cannot be guarded on all sides and operate effectively.

OSHA issued a response letter stating that the existing Grain Handling Standard (1910.272 (g) (1) (ii), “is not intended to be prohibition against employees entering grain storage structures while machinery is running.” In late 2008, the insurance representative sent a second letter inquiring if unguarded sweeps can be in operation (energized) in a grain bin while an employee is inside the bin. In response, OSHA issued a Letter of Interpretation stating that it is in violation of 1910.272 (g) (1) (ii) unless the employer can eliminate all hazards presented by an energized unguarded sweep auger.

Given the basic functionality requirements of sweep auger operations, OSHA’s 2009 Letter of Interpretation baffled the industry with these seemingly impossible restrictions.

The letter, dated Dec. 24, 2009, does not and has not specifically defined what is meant by a guarded or unguarded sweep auger; or what types of procedures are acceptable for operating a guarded auger in the bin. Compounding the lack of guidance, it fails to give the industry any options or a timeline for retrofitting the equipment nor does it grandfather existing structures/equipment installations that will not be easily altered.

The National Grain & Feed Association (NGFA) was quick to act, and contacted OSHA looking for clarification on some of the terms of the letter. To date, OSHA has yet to formally respond to NGFA’s request.

Key challenges

“The whole thing is impractical, it’s unreasonable — then again, OSHA and practical can’t always be used in the same sentence,” says Wayne Bauer, director of safety & security, Star of the West Milling Co. “I have to believe that if OSHA doesn’t reverse its stand there will be thousands of sweep augers that will not function without somebody in the bin.”

Especially unfortunate for the grain industry is that the design criteria for the storage vessels of 30 years ago are incredibly different than modern standards of operation — especially when considering physical access to the sweep. Today most unload systems can be accessed from the underside of the bin through tunnels and other access points; in contrast, older systems don’t have the infrastructure, capacity size or access points available to support commercial sweeps.

As a result, many facilities settle for lighter, farm-duty applications.

“There are options, but often that cost supersedes the cost of the sweep,” Darren Zink, strategic accounts manager, Brock Grain Systems, says. “[The investment] is incredibly impractical and very cost prohibitive to the point where the silo has been depreciated to zero so to put money toward very little gain isn’t an option.”

Given the vague interpretation, many asked themselves if OSHA has a firm understanding of how the equipment actually works.

“OSHA is great for coming up with rules, but not for offering options and instruction as to how to comply,” Bauer says. “They’re sitting in Washington trying to imagine what this piece of equipment looks like — and restricting something when they have no understanding of how it works. If you’re not willing to take the time and make the effort to study the process, then you have no right to try to make rules about how it works.”