Mixing slurry can be a particularly dangerous job as slurry gas is released very quickly, and in large quantities, as soon as the mixing starts.

The Health and Safety Executive for Northern Ireland (HSENI) is reminding farmers to take extra care when working with slurry.

Slurry gas is a mixture of gases, including the extremely poisonous gas hydrogen sulphide. Even a low concentration of hydrogen sulphide can knock out your sense of smell so you won’t even know it’s there, the HSENI says.

One breath

At higher concentrations, you will rapidly find it harder to breathe and become confused – and at certain concentrations, just one breath can kill.

The first 30 minutes are the most dangerous, so it is important for farmers to leave the shed as soon as mixing starts, and to stay out for at least 30 minutes.

“Before starting any job on the farm, including slurry mixing, take time to stop, think and safely plan the work ahead," Malcolm Downey, principal inspector of HSENI’s farm safety team said. “Cover openings and keep children and animals far away during the slurry mixing process. Stay out of the building for at least 30 minutes after the mixing starts and every time you move the pump or change the direction of mixing. Please be aware that if a tank is mixed before the end of the closed period and is then mixed again before the tank is emptied that gas can build up again even within a day or two and it is essential to stay out for at least 30 minutes once again."

He reminded farmers that "just one breath can kill".

The slurry mixing code

  • Keep children away from the area at all times when working with slurry.
  • If possible, mix on a windy day.
  • Open all doors.
  • Take all animals out of the building before starting to mix slurry.
  • Use outside mixing points first.
  • If slats are removed, cover exposed areas of the tank beside the pump/mixer to stop anything falling in.
  • Start the pump/mixer, then get out and stay out of the building for as long as possible – at least 30 minutes
  • Any time you have to go into the building, try to make sure that another adult knows what you are doing and can get help if necessary.
  • If you have to re-enter to move the pump or change the direction of the pump, leave the building as soon as this is done. Do not go back in for as long as possible – at least another 30 minutes.

    • Never

  • Rely on filter-type facemasks.
  • Use gas monitors as a substitute for working safely.
  • Have naked flames near slurry, as slurry gas mixture is flammable.
  • Stand close to the exhaust of a vacuum tanker when it is being filled.

    • If you find someone has been overcome during slurry mixing, If possible, stop the pump and get the person to fresh air but do not put yourself at risk in the process. If breathing is weak or stopped, artificial respiration may be effective. Contact the emergency services and seek immediate medical attention.

    For more information about working safely with slurry, contact the HSENI helpline on 0800-0320 121 or visit the farm safety topic page on the HSENI website: www.hseni.gov.uk