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Caution with slurry - evacuate, ventilate, agitate

Caution with slurry - evacuate, ventilate, agitate

A challenging start to 2024 has resulted in the agitation and spreading of slurry being delayed on many farmers, leaving farmers and contractors with a backlog to work through. But before attempting to agitate, make yourself aware of the risks.

Handling slurry is one of the most hazardous activities on a farm. The main risk associated with handling slurry is being overcome by slurry gases, leading to poisoning, suffocation or drowning. Machinery risks include impact or crushing when attaching the agitator or tanker and entanglement on the PTO.

Slurry gassing

Slurry produces a range of gases based on the nature of the fermentation which occurs. Poisoning occurs ‘above ground’ due to the release of Hydrogen Sulphide (H2S). H2S can be detected by smelling at 0.1 ppm. At 150 ppm, the olfactory nerve which detects smell in the nose is desensitised and then H2S cannot be detected by smell. The gas produces adverse health effects at increasing concentration and is rapidly fatal above 700ppm. Teagasc measurements have indicated that fatal levels of gas can occur in the period after agitation commences.

Key points with agitating:

  • Remember the rule – evacuate, ventilate, agitate.
  • Only agitate on a breezy day when there is considerable air movement, as one lung full of hydrogen sulphide gas released during agitation can kill.
  • Ensure that all livestock, people and pets are kept clear of the slatted shed when agitating.
  • Make sure that buildings are well ventilated with all doors and outlets open.
  • Stay away from the agitation point and of out the slatted shed for at least 30 minutes after starting agitation.
  • Additional time must be given where there are linked tanks and linked buildings, as slurry gas, which is heavier than air, may travel into poorly-ventilated locations within these sheds.
  • Slurry gas can also travel through linked tanks and pipes to locations away from the tank,
  • Check for, and stay out of, blind ends where slurry gas may build up.
  • Never enter a slurry tank – even if empty – as gases may linger.

Additionally, indoor agitation points are very dangerous and should be avoided. There are a number of options available to farmers to avoid the need to use indoor agitation points, including: extending tanks and the installation of outdoor agitation points; fitting a slurry circulation pipe; pumping slurry to an outdoor large capacity tank; installing a slurry aeration system and/or the use of slurry additives.

Teagasc, FBD and the Farm Safety Partnership produced a video on slurry handling safety. Watch the video below for more key tips: