Commodity Watch - There is no silver bullet for slurry safety

Saturday, 7 February, 2015

Commodity Watch - There is no silver bullet for slurry safety

With the slurry spreading ban now being lifted, the Farm Safety Partnership has been turning its attention to the safety of farmers who will now be using this slurry to fertilise their fields. The dangers faced by these farmers from the deadly hydrogen sulphide gases are well known, but the solutions to the problem remain very much a work in progress.

There has been an unfortunate focus on a “silver bullet” fix for this issue: whether this has been the use of gas monitors, personal protective equipment or additives which will reportedly neutralise the dangerous gases, however, none of these have been shown to be fool proof. The Farm Safety Partnership has therefore consistently given out the message that any one of these measures, taken in isolation, cannot be relied on fully. For example, even a properly maintained gas monitor will not pick up the rapid rise in hydrogen sulphide levels when mixing starts and thus will not give enough warning time to allow for escape. Personal protective equipment, such as facemasks will often require specialist fitting, and if not fitted properly, will not provide adequate protection.

The advice given by the Farm Safety Partnership, on the other hand is that, while none of these measures will solve the problem on its own, if used in combination with other safety techniques, they may provide a workable solution. For example, the concentration of dangerous gases will ‘spike’ within the first thirty minutes of mixing(including any repositioning of the pump) and there is no substitute for simply exiting the building for this period. When re-entering the building following this period, slurry gas monitors may provide part of a safe system of work. Adequate ventilation and communication with others outside the building also have a very important part to play. There is no simple answer to the problem, but there are lots of simple measures which will mitigate the risk to farmers.

The Farm Safety Partnership has also set up a Slurry Working Group, tasked with reviewing current practices relating to the storage and handling of slurry on farms in Northern Ireland  and to  report to the FSP on actions or measures which could be taken to reduce risk and prevent incidents. This Group is made up of scientists, farmers and health and safety professionals, and will publish its report on the current situation and possible ways forward in Spring 2015.

With the spreading of slurry well underway (HSENI) is urging farmers to take extra care when working with slurry. Follow the slurry mixing code to stay out of trouble:

  • keep children away from the area at all times when working with slurry
  • If possible, mix on a windy day
  • open all doors and windows
  • 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


  • 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