Agitation fumes from slurry can be lethal unless you take the necessary precautions
The ban on spreading slurry is set to lift over the coming weeks, depending on where you are based in the country.
Weather permitting, this means slurry agitators and tankers will be springing into action on farms. Against the backdrop of another bad year in 2016 for farm fatalities, now is a good time to brush up on the dos and don'ts when it comes to working safely with slurry.
One man who knows the lethal nature of slurry fumes all too well is Noel Tierney, a farmer from Miltown who was full-back on the Galway team that won an All Ireland senior football three-in-a-row between 1964-66.
In 1993, Mr Tierney's son, Fergal, died trying to save him after he himself was overcome by slurry gases on their farm in Miltown.
"On the day of the accident we were emptying a slatted tank under a calf shed. The tank had less than a metre of slurry in it - I'd say only around two foot deep. I noticed there was a crust on top and decided to give it a quick mix.
"There was one calf in the shed and Fergal went to the other end to let him out into a pen to avoid the fumes.
That's the last I remember; I must have passed out with the fumes.
"I always assumed there would be some warning sign, that you'd feel a weakness, but I didn't feel any weakness - just a blank memory. When I came around again, my wife told me that Fergal had tried to save me but he himself had been overcome with slurry fumes.
"Unfortunately he didn't make it. Looking back now, I always remember the stillness of the day.
"There was no wind whatsoever. The biggest piece of advice I would give to farmers is to only agitate and spread slurry on a day when there is good air movement. Make sure to stand well clear when agitating to let the fumes disperse."
The dos and don'ts of slurry spreading
Gases are produced from the bacterial decomposition of slurry in storage and are then released during slurry agitation when the crust is broken.
The main gases produced include ammonia, carbon dioxide, methane and hydrogen sulphide. The latter is the most deadly, and at high concentrations it has the power to render unconscious and kill humans and animals who happen to be in the vicinity of the agitation point.
Hydrogen sulphide is a clear gas that is slightly heavier than air. Crucially, this means that it does not disperse easily, but stays low to the ground. It is for that reason that the Health and Safety Authority (HSA) and Teagasc tell farmers to open all available ventilation points to provide a through draught, especially at floor level.
From a safety point of view it is also a good idea to try to agitate and spread slurry on a windy rather than a calm day.
The gas release is greatest in the first 15-30 minutes of agitating.
The concentrations are particularly high after the winter closed period because the slurry has been stored and has been decomposing over a number of months.
The crust on top acts to trap the gases, but on breaking the crust and mixing the slurry this natural barrier is removed.
According to the HSA, the single most important safety measure when agitating slurry is to remove yourself, all personnel and all livestock from buildings near to the slatted tank before you start.
But that alone isn't enough; you also need to stay out of any buildings for up to the first hour of agitation.
Obviously, children need to be kept away entirely. It is a good idea to have another person with you when agitating, but if that is not possible then at least inform someone of what you are doing.
That way, should something go wrong the alarm can be raised.
While asphyxiation from slurry gases is a serious danger, it is not the only threat or danger related to slurry spreading on farms.
The fatal farm accident data concerning slurry-related fatalities available from the HSA indicates that 75pc of victims drown in the slurry as opposed to being gassed by fumes.
This data is based on the outcome of a coroner's inquest, so it is the best information available.
The HSA say drowning is the most common slurry-related farm fatality, with some 30pc of child fatal accidents on farms and 8pc of deaths among elderly farmers being caused by drowning in slurry or water.
It is important to look at the farmyard, the types of slurry storage facilities and the precautions that are in place to prevent any such accident.
When slats or manhole covers are lifted or removed for agitation or when emptying the tanks, ensure that there is adequate temporary protection of such openings.
Slurry Agitation safety tips
Only agitate when there is good air movement
Evacuate all livestock
Make sure no one is in or near the building
Open all doors and outlets to provide a draught
At least two people should be aware of the job
Never stand over slats or near tank access points when agitation is in progress
Avoid vigorous agitation in confined places
Keep all people away from the agitation point for at least 30 minutes after starting agitation
Never enter or allow others to enter the any tank or confined place without breathing apparatus
Agitation points should be placed outside the building