Safety, Health and Emergency Readiness

Manure Storage Gas Hazards

Manure storage can release gases that are dangerous or deadly, sometimes with little warning. The safest approach is to treat every pit, tank and lagoon area as a hazard and plan work around that fact.

What the hazard is

As manure breaks down, it releases gases. Some, such as hydrogen sulfide and methane, are hazardous, and others, like carbon dioxide and ammonia, can also cause problems in the wrong conditions. Gases can build up in enclosed or poorly ventilated spaces.

Hydrogen sulfide can dull the sense of smell, so a person may stop noticing it while the danger rises. Do not rely on your nose. The CDC and OSHA publish information on these gases.

This hazard is not limited to large operations. Small farms with a single tank or sump face the same chemistry, and often have less equipment and fewer people to help in an emergency.

When risk goes up

Agitating, pumping or stirring stored manure can release a sudden burst of gas. Work in or near pits, tanks and covered storage deserves special care, as do low, still, humid days when gases linger. Be careful near connected buildings, since gases can travel.

Plan agitation for times when people and animals can be kept clear and ventilation is as strong as possible. Know where the wind is going, and keep people away from the area during the work.

A dairy near a feedlot or a crop operation may also share equipment or storage. Coordinate with neighbors on when pumping or agitation will happen.

Basic controls

Keep people out of enclosed storage whenever possible. Use equipment from the outside, mark hazards with signs and barriers and keep covers and openings secured. Provide ventilation, and use gas monitors where appropriate.

Do not let anyone work alone near storage. Make sure everyone knows the emergency plan. Equipment such as monitors needs maintenance and training to be useful.

If you must work near storage, use a written procedure, a trained team and appropriate equipment, and have a rescue plan in place before the job starts. If you cannot meet those conditions, do not do the job.

• Signs and barriers around storage
• Secure covers and openings
• Ventilation during agitation
• Gas monitors, maintained and used
• Never work alone near storage

Rescue: why you must not improvise

People are often hurt or killed when a second or third person rushes in to help someone who has collapsed. Do not enter. Call emergency services immediately. Trained rescue teams with proper equipment are required for any rescue in a hazardous atmosphere.

Make sure everyone on the dairy knows this rule, including family members and visitors, and post the emergency number and your farm address where people can see them.

Symptoms of exposure can include headache, dizziness, nausea, burning eyes and sudden collapse, and they can progress fast. Treat any such symptoms near storage as an emergency.

Training and planning

Everyone who works near manure storage should know the hazards, the signs of exposure and the emergency plan. Training should be hands-on and in a language people understand. Review it every year.

Short toolbox talks before agitation work keep the risk fresh. For more on planning, see this farm safety guide, and for dairy operations see this dairy herd care guide. TCEQ covers environmental rules on manure management, so confirm those with the agency.

Keep records of training, equipment checks and incidents. These records help you improve and show your insurer and regulators that you take the hazard seriously.

Animals and children

Gas can harm livestock and pets too. Keep children away from storage areas, fence them off and teach everyone that these places are not for play.

Visitors and new hires should be told on day one where the hazards are. Ready.gov has emergency planning ideas that apply here.

Dogs and farm cats are also at risk around storage. Keep them away, and remember that a pet that goes missing near a pit can be a warning sign that something is wrong. Workers' compensation questions go to the Texas Department of Insurance.

More information

For help, ask Texas A&M AgriLife Extension about manure management training. For background reading, farm.FM has dairy stories and farming stories, including a farm.FM piece on manure handling.

This is general education, not a substitute for professional training.

If you are unsure about a space, treat it as hazardous. Ask a qualified safety professional to evaluate it before anyone works there.

Sources and further reading

• CDC: public health
• OSHA: workplace safety
• TCEQ: Texas environmental regulator
• Texas A&M AgriLife Extension: Texas extension service
• Ready.gov: FEMA disaster preparedness
• National Weather Service: forecasts and warnings

Ask locally: Ask OSHA, your extension agent or a qualified safety professional about gas monitoring and training.