How to Stay Safe Around Manure Storage Systems

By Blake Jackson

Confined livestock and dairy systems are widely used in U.S. agriculture, but they can present serious safety risks, especially when handling manure storage. According to Dennis Murphy, Professor at Pennsylvania State University, these systems often rely on automated feeding, ventilation, and manure management, with waste stored in underground pits or nearby tanks. While efficient, these setups can create hazardous confined spaces.

Manure storage structures typically meet the definition of a confined space under Occupational Safety and Health Administration standards, meaning they have limited entry points, are not designed for continuous occupancy, and can expose workers to serious dangers.

These hazards include low oxygen levels, toxic gases such as hydrogen sulfide, and the risk of drowning. Because these gases are often colorless and odorless, they can go undetected, making entry extremely dangerous.

Historically, manure storage accidents have resulted in fatalities, often when individuals unknowingly enter these spaces without proper precautions. To reduce risks, experts recommend using portable gas monitors to check oxygen and gas levels before and during entry. These devices should be well-maintained and properly calibrated to ensure accuracy.

Proper ventilation is also essential. A positive pressure system that forces fresh air into the storage helps maintain safe oxygen levels and reduces the buildup of harmful gases. Ventilation should begin before entry and continue throughout the process.

If entry is unavoidable, safety procedures are critical. Workers should wear harnesses with lifelines connected to rescue systems, and a second person must remain outside to monitor conditions and assist in emergencies. Avoid entering during manure agitation, as gas levels can rapidly increase.

Although some farms are exempt from specific OSHA rules, operators are still responsible for maintaining safe working conditions. Careful planning, proper equipment, and adherence to safety practices can significantly reduce the risk of injury or death.

Recommendations to improve safety around manure storage systems:

• Always use a properly calibrated gas monitor to check oxygen levels and detect toxic gases like hydrogen sulfide before entering any storage area.
• Use a positive pressure ventilation system to supply fresh air and reduce harmful gas buildup prior to and during entry.
• Wear a full-body harness with a lifeline connected to a rescue system to allow quick retrieval in emergencies.
• Have a trained second person outside the confined space to monitor conditions and assist if something goes wrong.
• Do not enter manure storage when manure is being stirred or moved, as gas levels can rise quickly and become deadly.

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