Farmers are being urged to make their safety a priority when mixing slurry ahead of the closed spreading period
Officials from the Farm Safety Partnership and the Health and Safety Executive for Northern Ireland (HSENI) are advising farmers to stringently follow the slurry mixing code and warning just one breath of poisonous slurry gas 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. 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 – and at certain concentrations, just one breath can kill.
The slurry mixing code
- 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
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
Find out more about working safely with slurry.
First published 23 September 2025
