Farmers – take care when mixing slurry

Date published: 01 October 2018

With the closed period for slurry spreading due to commence at midnight on 15 October the Health and Safety Executive for Northern Ireland (HSENI) is urging farmers to take extra care when mixing slurry.

Mixing slurry - one breath can kill

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.

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. 

Malcolm Downey, who heads up the farm safety team at HSENI, appeals to farmers mixing slurry before the commencement of the closed period. Mr Downey said: “Do not take any chances when mixing slurry, your life may depend on it. Stop and think about the entire job ahead and ensure you follow the slurry mixing code.

“When mixing slurry keep children and animals away at all times. Farmers must stay out for 30 minutes after starting mixing or after moving or re-directing the pump.”

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
  • 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


  • 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

For more information about working safely with slurry contact the HSENI helpline on 0800 0320 121 or visit our farm safety topic page:

A hard-hitting survivor story video is also available on the HSENI YouTube channel where Co. Antrim farmer Alex Walker recalls his near fatal incident when mixing slurry: 

Notes to editors: 

  1. The Farm Safety Partnership’s ongoing ‘Stop and Think SAFE’ farm safety campaign focuses on the four main causes of death and injury on our farms – slurry, animals, falls (from height) and equipment (SAFE).
  2. The Farm Safety Partnership, which comprises the HSENI, the Department of Agriculture, Environment and Rural Affairs (DAERA), the Ulster Farmers’ Union (UFU), NFU Mutual (NFUM), the Young Farmers’ Clubs of Ulster (YFCU) and the Northern Ireland Agricultural Producers Association (NIAPA), is tasked with assisting Northern Ireland’s farming community to work safely and tackle the problem of work-related fatalities and injuries on farms. 
  3. The Farm Safety Partnership Affiliate Scheme is made up of the following organisations – ABP Group; AES UK and Ireland; Asda; Autoline Insurance; Dale Farm; Danske Bank; Girlguiding Ulster; Glens of Antrim Potatoes; IOSH NI; Lakeland Dairies; Lantra; Livestock and Meat Commission Northern Ireland; Northern Health and Social Care Trust; Northern Ireland Safety Group; Power NI; Rural Development Council NI; Ulster Bank and the University of Ulster – School of Nursing.  These organisations support the Farm Safety Partnership by working to raise the profile of farm safety in Northern Ireland. 
  4. The Health and Safety Executive for Northern Ireland (HSENI) is an Executive Non-Departmental Public Body, sponsored by the Department for the Economy.
  5. HSENI is the lead body responsible for the promotion and enforcement of health and safety at work standards in Northern Ireland.
  6. For media enquires please contact:  HSENI Press Office on 028 9024 3249 or email:
  7. For out of office hours please contact the Duty Press Officer on 028 9037 8110.

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