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Methane Gas Safety in Manure Storage

Manure storage can produce methane, a gas that can ignite and that can also displace the air people need to breathe. Here is how to think about the hazard and who to ask for site-specific advice.

Why does manure storage produce methane?

When manure breaks down without oxygen, microbes make several gases, and methane is one of them. It collects in the headspace of tanks, pits, covered lagoons and enclosed storage, and it can build up in buildings where ventilation is poor.

Methane has no smell of its own. Other gases from the same manure may smell, but you cannot use odor to judge whether methane is present or how much.

If your farm uses a digester, a covered lagoon or any system built to capture gas, the hazards deserve even more attention. Those systems are designed to hold gas on purpose, and the people who operate them need training specific to that equipment.

What are the two main dangers?

The first is fire and explosion. Methane can ignite from a spark, a flame, a hot surface or static, and an enclosed space can magnify the effect. The second is that methane can push out oxygen in a confined space, so a person may lose awareness without any warning sign.

These hazards are why manure storage should be treated as a place that needs planning, not a place for quick improvisation or casual visits.

• Ignition risk from sparks, flames and hot work
• Oxygen displacement in enclosed spaces
• No odor warning from methane itself

Where are the highest-risk spots?

Covered or closed tanks, below-ground pits, pump-out chambers and the airspace under slatted floors are the typical places for gas to collect. Any low area connected to a pit can hold gas that is heavier or lighter than the surrounding air depending on the mix.

Newer systems, such as covered storage or digesters, change the picture. If your farm has one, follow the designer's and manufacturer's safety instructions and ask a qualified professional about your site.

How do I reduce the risk of ignition?

Keep ignition sources away from manure storage openings and enclosed spaces. That includes smoking, welding, cutting, grinding and equipment that can spark. Any hot work near a pit or tank needs a written plan that comes from an official source or a qualified professional.

Electrical equipment in or near storage should be installed and inspected by a qualified electrician who understands agricultural buildings. Ask your local code official what applies to your area, because requirements differ by state and county.

Static electricity and tools can also be a source of ignition in the wrong setting. When in doubt, treat the area around a pit opening as a place where open flames and sparking tools do not belong, and ask a qualified source before doing any repair work there.

• No smoking near storage
• Hot work only under a plan from a qualified source
• Have wiring inspected by a qualified electrician
• Keep openings and vents clear as designed

What about ventilation and entry?

Good ventilation helps keep gases from collecting, but it does not make a pit safe to enter. Entry into manure storage is confined space entry and calls for trained people, proper equipment and a rescue plan that does not rely on untrained workers jumping in.

If you do not have trained and equipped people, hire a qualified service and stay out. OSHA and NIOSH have material on confined spaces in agriculture, and the exact requirements for employers are for OSHA and your state plan to explain.

What should I do in an emergency?

If anyone collapses, feels dizzy or confused near manure storage, or if you smell gas or see a fire, call 911. Move away, keep others away and do not go into the space to help. Tell the dispatcher where the storage is and how to reach it.

Learning first aid and emergency response should happen in a class with hands-on practice. The Red Cross lists courses, and local fire departments or extension offices can often point you to farm-specific training.

After any incident or near miss, even a minor one, sit down with everyone involved and write down what happened. Share it with your extension office or insurer if you wish. Small events often reveal the gap in a plan before a serious event does.

How can I build a safer routine?

Write down a short safety plan for manure work: who does it, how others are kept away, how ventilation is handled, what the ignition rules are and who gets called. Review it each season, and any time equipment or buildings change.

Keep the manuals for pumps, agitators and ventilation fans where people can find them. Then walk your site with your insurance advisor, extension agent or local fire department and ask what they would add.

Last reviewed: November 12, 2026. Written by the Farm Safety Editorial Team. See our editorial policy.