Read the Progressive Dairy Canada digital edition

Don’t step into a confined manure space until …

Jeramy Sanford for Progressive Dairy Published on 02 March 2021

Imagine a regular day on the farm. You’re going about your chores as usual until the pump in the manure transfer pit under the barn breaks. You go down in the pit to fix it, but suddenly you’re overcome by manure gas. No one ever expects a manure-related incident to happen, yet they do all too frequently.

Here are a few fast facts on manure-related incidents:



  • Nearly 150 people have died from manure gas incidents in confined spaces since the 1960s in the U.S.

  • About half of these incidents occurred on dairy farms.

  • Almost 25% involved someone under age 16.

  • Making repairs or performing maintenance on manure equipment accounted for 34% of deaths.

  • Trying to rescue another person entrapped or overcome by gases in manure storage or a reception pit resulted in 22% of deaths.

Two to three deaths per year may not seem like a lot, but it’s likely two or three more than should have happened. Safety precautions for working in confined manure spaces can help prevent these incidents from occurring. And they may just save your life or the life of one of your loved ones or your hard-working employees.

Step 1: Know confined space standards

Confined spaces are areas large enough for someone to enter and perform work but restricted to enter or exit. They are not designed for continuous occupancy.

In many industries, confined spaces are regulated by the Canadian Centre for Occupational Health and Safety (CCOHS). By following its standards you can employ the best safety practices to reduce risk of a manure-related incident on your farm.

Step 2: Identify potential hazards


Review and identify confined spaces around your farm that could be hazardous. Manure storage tanks, pits, manholes and tankers all fit into this category. Hazards for these confined spaces include lack of oxygen, toxic and flammable gases, and drowning.

While only a few employees might work around these spaces, all employees should know the dangers of manure gas exposure and how to reduce their risk.

Warn people of potential hazards in these areas by posting warning signs. Make sure these areas have protective fences or locked gates, and always barricade entry to the area when in use. These practices are important for anyone who steps foot onto your farm.

Step 3: Employ safe steps for confined space entry

Reduce exposure to manure gas by putting safety steps in place for entering confined spaces. Complete a written entry plan for each space and review it annually with all farm staff.

Use the following as a guideline for creating your entry plan:


Test air quailty1. Test air quality

Before entering a confined space, use gas detection equipment to determine concentrations of hazardous gases and oxygen levels. A four-gas meter can detect oxygen deficiency and three additional hazards – typically flammability, carbon monoxide and hydrogen sulphide. They can be purchased for about $650 or rented for about $45 per day.

Always test and monitor air quality before entry. Stay outside of the space when taking the initial measurements. If dangerous or questionable concentrations are present, do not enter the space until it has been properly ventilated. Once the space is safe to enter, continue monitoring air quality for the duration of time you are in the space.

Manure storage pits, empty or full, are common places for high concentrations of manure gas to accumulate. Keep in mind: Manure gas can also be present outside of these spaces.

Ventilation2. Ensure proper ventilation

Make sure the space has proper ventilation to reduce the risk of asphyxiation, poisoning or explosion. Use extra caution for manure storage, reception or transfer pits where manure gas can accumulate faster.

Ventilation requirements vary by space dimensions and design. Forcing fresh air into the space using a mechanical ventilation system reduces the possibility of fire or explosion that could occur when gas comes in contact with electric fan motors. Fans should be able to move an air volume equal to half the volume of the space every minute.

Use established engineering standards for guidance on ventilation capacity and ventilation time before entry and during occupancy. Your local manure equipment dealer can also help determine proper ventilation based on your manure storage.

If it’s not possible to ventilate the area, wear a correctly fitted and approved self-contained breathing apparatus (SCBA) respirator. Know you’re still at risk for an explosion without proper ventilation. Test respirators annually to ensure they are properly functioning.

Never work alone3. Never work alone

Always have two people at the confined space site at a minimum. The person who enters the space must be knowledgeable about the space itself, the hazards that exist and what to do if something goes wrong. The second employee must remain outside the space in case an emergency occurs. Both employees need to be able to communicate visually, by phone or two-way radio to ensure safety.

Lockout power sources4. Lockout power sources

Always use lockout/tagout (LOTO) practices when you’re working on electrical-powered manure equipment. LOTO ensures the power is shut off and no one can turn it back on while you’re making repairs or maintenance.

Just shutting the power off isn’t enough because it doesn’t prevent someone else from coming along and turning it back on. LOTO practices are a simple and effective way to ensure a safe working environment, although few farms use them. They can be implemented with minor investment – a basic electrical or breaker kit costs about $175.

Use safety equipment5. Use safety equipment

Use appropriate safety equipment for the job. If you must enter a confined space, always wear a body harness attached to a fall arrest and retrieval system. While falling is typically not an issue for most manure storage emergencies, the ability to be safely retrieved is crucial.

Always have rescue equipment such as ropes, ladders, lifts and SCBA-equipped respirators available at the site.

Step 4: Create an emergency action plan

Make sure you have an emergency plan for quick removal of the entrant if necessary. Remember, 22% of manure-related deaths have been the result of trying to rescue someone. Never attempt to rescue someone who has been overcome by manure gas unless you have been trained, have assistance from a backup crew using a lifeline and are wearing an SCBA-equipped respirator.

Outline emergency procedures for all employees and local responders. Communicate the plan to your employees, post it at all confined space locations, and ensure it is reviewed and updated regularly.

These life-saving steps can keep you, your family members and employees safe when working around confined manure spaces. Always be aware of your surroundings and think safety first.  end mark