Updated Oct 18, 2022

HSENI remind farmers of slurry mixing dangers

The Health and Safety Executive for Northern Ireland (HSENI) is reminding farmers to follow the slurry mixing code to stay safe, as the closed period for slurry spreading began on Saturday 15 October 2022.

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

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

The first 30 minutes are the most dangerous, so it is important to remove all stock from the shed before mixing starts and for farmers to leave the building as soon as the mixing starts. It is also vitally important to stay out of the shed for at least 30 minutes after the mixing starts. 

Camilla Mackey, Principal Inspector of the Agri-Food team at the HSENI, said:

"Coming up to the closed period can sometimes be hectic for farmers trying to get the last of their tanks emptied. Do not take any chances when mixing slurry, it is not worth losing your life over. Stop and think about the entire job and ensure you follow the slurry mixing code.

"Always keep children and animals away at all times during the mixing process. Farmers must stay out of the shed for 30 minutes after mixing starts or after moving or re-directing the pump."

The slurry mixing code

The slurry mixing code advises the following:

  • open all doors and windows;
  • if possible, mix on a windy day;
  • keep children away from the area at all times when working with slurry;
  • take all animals out of the building before starting to mix;
  • 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;
  • if you have to go into the building, make sure that another adult who knows what you are doing stays outside and can get help if needed;
  • 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.

You should also make sure that you never:

  • rely on filter type facemasks;
  • use gas monitors as a substitute for working safely;
  • rely on monitors at the start of mixing, the volumes of gas could exceed the capacity of the monitor;
  • have naked flames near slurry, some parts of the slurry gas mixture is flammable;
  • stand close to the pump/exhaust of a vacuum tanker when it is being filled.

For more information, see: