An agricultural confined space can be a very dangerous space that may contain hazardous and explosive gases, low oxygen and other physical hazards. You should identify confined spaces at your business, make sure all employees understands their dangers, and implement protocols to ensure entry into these spaces, if required, is done safely every time.
A confined space is any space that (1) is large enough to enter and perform work, (2) has restricted means for entry or exit, and (3) is not designed for continuous worker occupancy.
Common farm examples include tanks, silos, bins, pits, manholes, and culverts.
If these spaces also have the potential for a hazardous atmosphere (like manure gas), could engulf a person (like grain in a silo), have sloped downward floors (like a manure drop or grain bin), or other serious safety risk, they are actually a permit required confined space.
Agricultural business owners should label these spaces with warning signs stating they are dangerous and should not be entered.
Owners should also develop standard operating procedures and train employees to safely enter and work in these spaces if they have to.
A pre-entry checklist should be part of a confined space entry protocol. It should include:
DESCRIPTION
A general description of the confined space and of what work will be performed.
NAMES AND INFO
Names of the people involved in the work, their competency and training. This includes both the name(s) of those entering the space (entrants) and the name(s) of the those who will stay outside the space to support those working within (attendants).
A PLAN
A plan for how the entrants and attendants will stay in contact with one another. This could be verbal if the space is small and work activities are not noisy, but radio headsets may be required if this is not the case.
HAZARDS AND POTENTIAL HAZARDS
The potential hazards, including atmospheric (hydrogen sulfide in manure gases), mechanical, electrical, thermal, fire and explosion, entrapment etc.
MORE PLANNING
How these hazards will be evaluated and controlled, including worker personal protective equipment.
Remember, if a space contains or has contained manure, hydrogen sulfide risk is always present! The only way to safely evaluate the presence of this gas, other hazardous or explosive gases, and to ensure safe oxygen levels, is with a calibrated gas meter.
Four-gas meters are equipped with pumps so the atmosphere of the confined space can be safely tested from outside. In pits and tanks the air should be sampled at different heights as gases can sit in layers.
While the air may be safe at the top entrance, it may not be further down in. Air monitoring should be done before workers enter but must continue during the work as conditions can change, sometimes quickly. For example, as manure solids in a tank are being walked in or shoveled, manure gases can be released.
RECOMMENDATIONS AND RESCUE PLANS
Any additional safety recommendations and an emergency rescue plan should also be part of the pre-entry checklist.
Workers may need to wear harnesses with a tagline so they can be pulled out of a confined space without others attempting to enter the space.
Local emergency services may not have the training and resources for confined space rescue.
It is also important to discuss these capabilities with your local first responders before performing work in a confined space.
Remember, it starts with prevention: the best way to ensure confined space safety is to change the way we operate so workers do not need to enter confined spaces in the first place.
Adding manholes to manure tankers between every baffle allows the tank to be flush with a firehose, meaning workers should never have to enter the thank.
It also allows a tank to be better ventilated if a worker absolutely must enter to remove a foreign object or make a repair.
For below-barn storage, manure aeration systems can be installed into these areas, to keep manure mixed, preventing accumulation of solids and the need to enter the storage to remove them – once again removing the need to enter the hazardous zones in the first place.
Like farming, safety is a team sport. We must work together to encourage and demonstrate safety and challenge each other to accomplish our work safely, every time.
For questions about manure handling safety, contact Jason Oliver, Cornell PRO-DAIRY.
