Reports of flash fires and explosions occurring recently in livestock barns while liquid pit manure was being agitated and pumped magnifies the need for farm safety when working on a hog operation.

Liquid manure in pits decomposes slowly, creating several gases including methane and hydrogen sulfide, both of which are flammable.

The rate at which the gas is released from the manure can be drastically increased when the manure is stirred during pumping. This increase is especially true for hydrogen sulfide, which can have a deadly paralyzing effect in addition to being flammable, according to Shawn Shouse, an Iowa State University (ISU) Extension area agricultural engineer.

Use strict safety protocols and ventilation and agitation practices to reduce the risk of flash fires and explosions during manure pumping.

Follow these safety tips from ISU and the Pork Checkoff:

  • Review your emergency action plan with all workers and keep emergency contact numbers on hand at the site. The Pork Checkoff’s Pork Production System offers ways to develop and implement an emergency action plan.
  • Prior to agitation or pumping, turn off electrical power to any non-ventilation equipment and eliminate any pilot lights or other ignition sources in the building.
  • Fully open all ventilation curtains or ventilation pivot doors but keep regular doors locked to prevent human entry.
  • Run ventilation fans at maximum speed.
  • Keep all people out of the building and tag all doors to warn of unsafe entry during agitation and pumping.
  • Agitate the manure keeping the jet of pressurized manure below the liquid surface.
  • Stop agitation when the manure level does not allow agitation below the liquid surface.
  • Continue maximum ventilation for 30 minutes after pumping has ended before reentering the building.
  • Never enter a building or manure storage structure when liquid manure is being agitated or pumped.