Tips for preventing asphyxiation due to manure gas
Most farmers are aware of the dangers associated with manure pits and take appropriate precautions when entering, but some may become more relaxed with the interior space of the confinement building. Farmers should remember that the toxic gases from the manure pit can travel through the slats in the floor making the entire building unsafe for entry.
It is often assumed that people will notice if there are unusually high concentrations of toxic gases within a hog building. However, this is not true. Hydrogen sulfide is the most acutely toxic gases from manure decomposition. Hydrogen sulfide deadens your sense of smell at high concentrations. This makes it difficult to respond appropriately when exposed to unsafe levels. Barns should be monitored for toxic levels of gas the same as you would in a manure pit.
Symptoms of exposure to toxic gases varies depending on the exposure level. For humans symptoms include eye, nose, and throat irritation, vomiting, nausea diarrhea, dizziness, unconsciousness, or rapid death.
There are precautions farmers can take to stay safe while working in confinement buildings.
- Test before entering. Using a gas detection monitor, those entering the building should test the levels of toxic gases before entering. These hand-held monitors can also be used while in the building to monitor for any changes in the gas levels and monitor the oxygen level. It is important to keep the monitor properly calibrated and maintained for accurate readings.
- Ventilate the area. A positive pressure mechanical forced air ventilation system is necessary for confined space manure pits. The ventilation system circulates fresh air into the storage area to replenish oxygen and redistribute other gases. Use ANSI/ASABE S607 for guidance about ventilation capacity and ventilation time prior to and during entry.
- Have a rescue and retrieval system. The person entering the confined space should wear an adjustable body harness with a lifeline attached to a combined rescue and retrieval system. In the event the person entering the space needs to be helped, this system will allow a second person to safely rescue them without having to enter the building and put themselves at risk.
- Use the buddy system. A second person capable of using the rescue and retrieval system should be stationed outside of the building near the entrance. This person should maintain visual or verbal contact with the person entering the storage area and be ready to call for help if needed.
- Know the first aid procedures to follow. Do not attempt to rescue a victim unless you are equipped with a self-contained breathing apparatus, have a proper rescue harness, and have assistance to get you out of the building. If you are able to safely rescue the victim, get them in fresh air, flush irritated areas with fresh water, and start CPR immediately, if you are trained, while you wait for medical help.
Following these safety procedures will help keep everyone working in the confined space manure pit on your farm safe. For more farm safety tips, check out SECURA’s Risk Management Resources.