Think about manure pit safety during fall nutrient application

manure application
Liquid manure from a hog feeding operation is being pumped onto cropland with a honey wagon. (USDA/NRCS photo, Tim McCabe)

By Denny Riethman | Ohio State University Extension

Harvest is wrapping up across Ohio. A common practice of livestock farmers is to apply manure nutrients following harvest before cover crops might be planted.

This is an important time to remind operators and applicators about the importance of following safety precautions when working around manure storage facilities. Planning ahead, developing standard operating procedures, ensuring everyone is well-trained and good communication helps reduce risks and keep everyone safe.

Manure pit gases are the biggest concern for health and safety around manure handling and storage pits. Hydrogen sulfide, methane, carbon monoxide and ammonia are gases of concern. Pit gases from any storage pit, whether closed, open or under barn storage, can be toxic to both humans and livestock.

Hydrogen sulfide (H2S) gas is the biggest risk and is extremely dangerous and highly unpredictable. Hydrogen sulfide gas is released when agitating and pumping manure. The gas is colorless, flammable and extremely hazardous with a rotten egg smell. The gas is heavier than air and will collect is low lying areas without good air movement. If it is in the breathing area for people or animals, it can be immediately dangerous to life and health.

Manure applicators and individuals working around the barn and confined spaces should be equipped with H2S monitors or multi-gas detectors that will provide alerts when levels are increasing. The alert system gives workers time to move away from higher gas concentration areas. H2S gas concentration levels of 2 to 20 ppm will cause symptoms of nausea, headache and dizziness. H2S levels greater than 100 ppm will cause altered breathing, collapse and death.

Exposure to ammonia results in immediate burning sensation and redness in the eyes. Methane and carbon monoxide are odorless and difficult to detect by smell. The dangerous consequences of exposure to any or all of these gases increases the importance of having multi-gas monitors in livestock buildings with manure pits below or around them.

Personal protective equipment

It is important to understand the different types of personal protective equipment, or PPE, available and the levels of protection they provide. Having a self-contained breathing apparatus or supplied-air respirator on hand is recommended.

Establishing a “Buddy System” in your operating procedures is important when working around manure pits in the event something happens, and someone collapses. A safety belt or harness should be worn as a lifeline should a worker need to enter a manure pit. This allows a coworker to stay in the peripheral area, keeping a safe distance away and pull them to safety should the need arise. The second person can also call for emergency help if needed. Properly operating ventilation systems are very important for enclosed barns with manure pits below. The ventilation system needs to exhaust the gases out of the barn, especially while stirring and agitating the manure. This is important for people working in the area, as well as the animals, to keep them from being fatally exposed to gases.

Think ahead about the process, making sure you are working with partners when maintenance work needs to be done in these areas. If you need to enter a confined space, ventilate the area for a period of time before entering the area. Follow the Lock Out, Tag Out procedure when doing maintenance or fixing equipment to ensure no one else accidentally starts equipment you are working on or repairing.

An ounce of prevention

Fencing and signage are important considerations around open manure pits to ensure that children, visitors and animals are kept out. Placing signage that indicates hazardous gases are present provides a visual warning and helps alert people to the risks in the area.

Producers and workers do not often see the susceptibility or severity of manure gas hazards. Building awareness and communication for everyone in the operation is key. Developing standard operating procedures, training and communication when working around manure pits is important. Along with making safety a mindset and part of the thought process as you go through daily tasks, these actions will reduce risks and keep people and animals safe.

Find more information about farm safety at

(Denny Riethman is an agriculture and natural resources educator with Ohio State University Extension in Mercer County.)


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