Sir, – It has come to our attention that certain commercial interests are promoting the sale of gypsum to farmers for use as animal bedding in slatted units and other holding facilities. It is also promoted for its beneficial effects on soil fertility.
While there is no dispute about the latter, there are dangers of using gypsum for under-bedding animals. Gypsum (CaSO4), when washed into slurry pits will, over time, break down under the anaerobic conditions pertaining in the pit thus releasing hydrogen sulphide (H2S). H2S is an extremely toxic gas. At low levels it is detected as a rotten egg-type smell and so is avoidable. At higher levels, however, it knocks out the nasal sensors and will kill instantly. Considering that there have been some very high profile cases of deaths due to H2S poisoning from slurry pits in Northern Ireland recently, where we understand the use of gypsum for this purpose is now banned, it beggars belief that this material is now being sold to farmers in the Republic without any warning to farmers of its dangers. The use of gypsum for the bedding of animals is also banned in England and Scotland and it should be banned here.
We hope it does not require further deaths for this to happen. – Yours, etc,