Always in Season--Manure Storage Safety
If you didn’t see the manure pit ventilation demonstration at this year’s Pork Expo, you missed out on a powerful visual of pit gas management. IPPA sponsored the safety demo, which was brought and operated by Dennis Murphy and Davis Hill of Penn State Extension. The take-home message: Equip everyone on your farm with the knowledge required to stay safe around manure pits.
Manure pit deaths can be prevented. The first rule is simply to avoid entering liquid manure storage facilities and transfer pits if at all possible. If someone must enter a pit, at least two people must be involved, with one (and preferably two people) remaining outside the pit as the attendant. A supplied-air respirator is commonly recommended for entry into confined spaces. Such equipment requires training and a “fit check” to be sure the mask seals well around the face of the person entering the pit. Because of the complexity and expense of maintaining and using a supplied-air respirator, few farm operations keep a respirator on hand for the occasional pit entry. One solution, arguably a remote second-best, is to (1) test the atmosphere in the pit before entering, (2) provide additional forced fresh air ventilation, (3) use a safety line, harness, and winch supervised continuously by attendants who can quickly pull the entrant out in case of problems, and (4) monitor conditions for toxic or oxygen-deficient atmosphere. Advance planning and training are absolutely necessary.
Here is the minimum equipment required:
a portable, electronic gas monitor for hydrogen sulfide, methane & other combustible gases, plus oxygen level
an electrically-powered (AC) ventilation blower, 900 to 1200 cubic feet per minute (cfm), designed for ventilating confined spaces
A safety line and rescue harness, tripod, cable and hand-operated winch system capable of raising and lowering an entrant in an emergency.
The person entering the pit should be trained on the use of the personal protective equipment. The attendants should also be trained, prepared for emergencies, and able to quickly get the entrant out of the pit if there is a problem. Someone on the site should be trained in CPR and first aid measures.
Test the atmosphere in the pit before entering, to see if the oxygen level is adequate and that the concentration of hydrogen sulfide is safe (below 10 ppm). If it’s not safe, don’t enter! Provide adequate forced ventilation into the pit using the blower. Keep flame and other ignition sources away, in case there is sufficient methane in the pit to support combustion. Keep a clear escape path for the entrant. Monitor the conditions in the pit, preferably with a gas monitor worn by the entrant.
Develop a safety culture on your farm. Use clear, generally acknowledged safety signs. Consider working with your insurance company for a facilities check and review. Teach and involve the kids. Support 4-H, FFA and other local efforts that encourage youth to learn about and identify hazards on the farm.
For more information on pit safety, see the Penn State Extension fact sheets at http://extension.psu.edu/business/ag-safety.