Many workplace environments present potential hazardous gas threats to those present, either occasionally or on a regular basis. Protecting workers from these dangers is a matter of understanding the specific threats and choosing the proper tools they need to stay safe.
Gases in agriculture can be found in silos, manure storages, anaerobic digesters, grain bins and improperly ventilated barns.
Structures that provide a confined space in which gases can accumulate to dangerous levels or deprive the air of enough oxygen to sustain life include silos, grain storage bins, slurry tanks, underground manure pits, water tanks and wells.
Plant material stored in a silo ferments, allowing the crop to be stored for a long time. However, the fermentation process can use up oxygen, produce carbon dioxide, and, under certain conditions, nitrogen dioxide as by-products. This results in an environment unsuitable for humans soon after the silo is filled and can sometimes last up to two weeks.
Manure that is stored for a long time undergoes anaerobic decomposition, which produces manure gases. Warm weather and poor ventilation can increase the concentration of these gases. Liquid manure tanks can contain toxic levels of gases or can be devoid of oxygen.