‘There is no such thing as safe slurry tank’ – Farmers warned over risks from deadly gases
29th January 2025
Farmers have been warned that a little-known deadly gas emitted by slurry, even in open spaces, is responsible for fatalities in farming every year.
The Wales Farmer Safety Partnership (WFSP) explained that hydrogen sulphide can be just as deadly outside as it is in confined spaces, and its toxic fumes can overcome farmers within seconds.
WFSP ambassador Alun Elidyr said: “There is no such thing as a safe slurry tank.
“It is more important than ever that farmers are aware of the risks of the gases in stored slurry with the new Control of Agricultural Pollution Regulations in force, with closed periods prohibiting the spreading of slurry and organic manures ranging from 1st August – 31st January, depending on land and crop type.”
Slurry contains multiple gases, including methane, ammonia and carbon dioxide, but the most dangerous of all is hydrogen sulphide.
“Just two or three breaths of this is sufficient to disorient or overcome a person.
“This gas is heavier than air, so it sits a metre or two above the surface of slurry. Anyone putting their head in that space, especially when a tank is agitated, can breathe it in without realising it.
“It has no smell, so you won’t be able to tell if you have been exposed to it,’’ Mr Alun explained.
Introduce a ‘buddy’ system
Agitation, when the tank is mixed to combine the solids and liquid element, is particularly dangerous because this process releases the gases. Livestock can also die from inhaling these fumes.
Mr Alun said that it is vital to adopt the ‘stop and think safe’ mindset before starting a job involving slurry, as is the case with any other farm task.
He advises: “Plan your work, that plan is your risk assessment. It doesn’t have to be written down, but the effect of having considered it is the most important process in your day, whether it is working with slurry, handling livestock, dipping sheep, working at height.’’
Financial and labour challenges and changes to farm practices mean that farmers often work alone, and this presents its own risks in these situations.
The expert reckons that a ‘buddy’ system, which is commonplace among foresters and involves lone workers checking in at agreed times with someone, would be highly beneficial for many farming operations, including slurry work.
“The ideal situation is that no farmer should be working alone, especially in high-risk situations, but when they are, I know of instances when the buddy system has saved lives,” Mr Alun added.
He also stressed the importance of following a safe system of working and assuming that hazardous gases are present around slurry, and to mitigate the danger.
A slurry gas monitor, which can cost less than £200, is advised, although WFSP cautions that they should not be completely relied upon.
Mr Alun concluded: “It is a grey area because anything over 200 parts per million (ppm) can be a danger, but there might be a breeze blowing through a shed with underground storage, and you don’t feel the effects but suddenly a bubble of gas rises and the level shoots up to 500ppm, which can have a life-threatening effect.”
He said farmers owe it to themselves and to the industry to do everything possible to prevent accidents from happening.
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