Confined Spaces: Emergencies and Rescue

Use the following format to cite this article:

Confined space: Emergencies and rescue. (2012) Farm and Ranch eXtension in Safety and Health (FReSH) Community of Practice. Retrieved from http://www.extension.org/pages/63150/confined-spaces:-emergencies-and-re….

 

Entering a confined-space manure storage area can be deadly. Farm and ranch managers, family members, and employees must have a complete understanding of what to do in the event of a confined-space emergency and ways to avoid such an incident.

If you find a victim unresponsive in a manure storage area, immediately call 911. Inform the operator that the incident involves a person in a confined-space manure storage area so that the appropriate emergency response personnel can be dispatched to the scene. Emergency responders trained in confined-space rescue will be equipped with the necessary rescue apparatus and gas detection equipment. Do not enter the manure storage area under any circumstances. 

While waiting for an emergency response team, ventilate the area by blowing fresh air into the space, moving the toxic air away from the victim. Keep a ventilation fan readily available specifically for such emergencies. When using a fan, be aware of the following recommendations:

  • Do not use typical barn or home fans to ventilate manure-storage areas because they may emit sparks from static electricity or an electrical short. If flammable methane gas has collected in the storage area, a spark could cause a fire.
  • Never attempt to get fresh air closer to the victim by lowering a fan into the confined space.
  • Make sure that the ventilation fan does not blow the manure gases back toward you, affecting your breathable air.

Preventing Confined-Space Manure Storage Emergencies

Take the following precautions on your farm or ranch to reduce the risk of a confined-space manure storage emergency:

  • Warning Signs: Post warning signs (example is shown below) about the risks of confined spaces and gas hazards at the openings to manure storage areas. Include warnings against walking or driving on crusted manure surfaces.

    Confined Space Sign

(Source: Pennsylvania State University. Agricultural Safety and Health)

  • Limited Access: Limit access to manure storage areas to authorized personnel. Take these specific steps to keep people away from manure storage areas:

    • Equip exterior ladders with locking mechanisms.
    • Remove temporary-access ladders from areas surrounding aboveground tanks.
    • When manure storage areas are open, place barricades at the openings of storage areas.
    • Install and maintain fencing around uncovered ground-level storage areas such as manure ponds or lagoons.
  • Education: Educate employees, family members, and visitors about the hazards associated with manure storage in confined spaces.
  • Entry Plan: Prepare and document an entry plan for entering confined spaces where manure is stored. Review the entry plan annually with all employees and family members. The entry plan should include specific physical details about the confined space, descriptions of potential hazards, reasons for entry, procedures for entry, and procedures to follow during emergencies. 
  • Two-Person Minimum: Require that two people be present for any confined-space entry and that both individuals be trained in entry and rescue techniques. The person outside the manure storage area should maintain verbal and visual contact with the person inside the confined space at all times. The person outside the storage area should be available to summon help and to implement the rescue and retrieval system if necessary. This person should not enter the manure storage area, even in the event of an emergency.
  • Gas Detection: Use gas detection equipment to monitor oxygen levels and levels of explosive and toxic gases in the confined space.    

Gas Monitor

(Source: Pennsylvania State University. Agricultural Safety and Health)

  • Ventilation: Prior to entry, ventilate the confined-space manure storage area for a minimum of 15 minutes and continue ventilation during entry and occupancy. A positive-pressure ventilation system is recommended because of the reduced risk of fire or explosion.
  • Body Harness: Require that the person entering the manure storage area carry a portable gas monitor and wear an adjustable body harness with a lifeline attached to a rescue and retrieval system. A typical rescue and retrieval system uses a tripod device equipped with a winch to limit a person’s fall and retrieve a person who has been incapacitated. 
  • Power-Source Lockout: To reduce the risk of stray electricity, prior to entry, lock out all power sources in the confined-space manure storage area other than the positive-pressure ventilation system.

Additional Safety Recommendations

  • Remember that youth under the age of 16 are prohibited from working in confined spaces.
  • Provide training about the hazards associated with confined-space manure storage to every person working on, living on, or visiting the farm or ranch.
  • Ventilate manure storage areas appropriately to increase oxygen and decrease explosive and toxic manure gases.
  • Remove personnel and animals from the confinement building during manure storage agitation or pumping. If you are unable to remove the animals, maximize ventilation and begin agitating very slowly while monitoring the animals for abnormal behavior.
  • Prohibit smoking in and around manure storage areas.
  • Operate manure agitators below the surface of liquid manure to reduce the release of manure gases. 
  • Leave 1 to 2 cu. ft. of space above the manure to contain released gases. If you are unable to leave the recommended space, lower the manure level prior to agitation.

 

Use the following format to cite this article:

Confined space: Emergencies and rescue. (2012) Farm and Ranch eXtension in Safety and Health (FReSH) Community of Practice. Retrieved from http://www.extension.org/pages/63150/confined-spaces:-emergencies-and-re….

 

Sources

 

Hallman, E. & Aldrich, B. (2007) Hydrogen sulfide in manure handling systems: Health and safety issues. Cornell University Manure Management Program. Retrieved from http://www.manuremanagement.cornell.edu/Pages/General_Docs/Fact_Sheets/H2S_Safety_factsheet_2007.pdf.

Hill, D., Murphy, D., Steel, J., & Manbeck, H. (2011) Confined space manure storage emergencies. Penn State Extension. Retrieved from http://www.agsafety.psu.edu/factsheets/E54emergencies.pdf.

Ogejo, J. (2009) Poultry and livestock manure storage: Management and safety. Virginia Cooperative Extension. Retrieved from https://pubs.ext.vt.edu/442/442-308/442-308.html.

 

Reviewed and Summarized by:
Linda M. Fetzer, Pennsylvania State University – lmf8@psu.edu
LaMar Grafft, East Carolina University – grafftl@ecu.edu
Davis E. Hill, Pennsylvania State University – (has since retired)
Dennis J. Murphy, Pennsylvania State University – (has since retired)
Aaron M. Yoder, University of Nebraska Medical Center – aaron.yoder@unmc.edu
 

Confined Spaces: Hazards of Manure Gases


Use the following format to cite this article:

Confined space: Hazards of manure gases. (2012) Farm and Ranch eXtension in Safety and Health (FReSH) Community of Practice. Retrieved from http://www.extension.org/pages/63141/confined-spaces:-hazards-of-manure-….

The Occupational Safety and Health Administration (OSHA) defines a confined space as a space that:

  • is large enough for a worker to enter and complete a task in,
  • has limited or restricted means of entry or exit, and
  • is not designed for continuous human occupancy.

Confined spaces on a farm or ranch in which manure handling may occur include manure pits, manure transfer pipes and deep gutters, transfer storage areas, and liquid manure spreaders. Farms and ranches continue to expand their operations to include larger manure handling systems. While these new systems are more efficient and reduce manual labor, farmers and ranchers must understand the hazards associated with working in and around confined spaces where manure is stored.  

Gases inside Manure Storage Areas

The breakdown of manure is a biological process, and environmental factors such as temperature, humidity, and air flow can impact the release rate of gases produced during this process. High temperature, lack of air exchange, and humidity can increase the levels of manure gases that are produced and released. The following hazardous gases form naturally in manure storage areas and are difficult to detect because of their properties, impact on a person’s sense of smell, and similarity to other odors on a farm or ranch:

  • Ammonia is found in manure pits or aboveground tanks used for manure storage and has a strong odor that can irritate a person’s eyes or respiratory system.
  • Carbon dioxide is a colorless and odorless gas associated with animal respiration and manure decomposition. Carbon dioxide can replace the oxygen in a confined space. If you breathe in air that contains high levels of carbon dioxide, this gas can replace the oxygen in your bloodstream and may result in headaches, drowsiness, and death (after prolonged exposure). Carbon dioxide is heavier than air, so it can easily accumulate in low-lying areas of confined spaces.
  • Hydrogen sulfide is a colorless gas that smells like rotten eggs at low levels but can overcome a person’s sense of smell at levels of 100 ppm and higher. Exposure to hydrogen sulfide can cause eye and nose irritation, headache, nausea, and death (after prolonged exposure). Hydrogen sulfide is heavier than air, so it can easily accumulate in low-lying areas of confined spaces.
  • Methane is a colorless and odorless gas produced during the decomposition of manure in storage. This gas is flammable and potentially explosive, especially when captured in foam that can form on the surface of stored manure. Methane is lighter than air, so it does not accumulate in low-lying areas of confined spaces.

Handheld gas detection equipment should be used to monitor gas levels prior to entry into and while occupying confined-space manure storage areas. Some equipment used to detect manure gases is configured to measure oxygen level, explosive gases (methane), and toxic gases (hydrogen sulfide).

For each of the hazardous gases mentioned above, OSHA has identified safe exposure levels for humans. Table 1 outlines the acceptable exposure limits in ppm over an eight-hour period. The oxygen level in a given space should be between 19% and 23%.

Table 1: Acceptable Exposure Limits
Hazardous Gas Acceptable Exposure Limits
Ammonia 50 ppm
Carbon dioxide 5,000 ppm
Hydrogen sulfide 10 ppm
Methane 1,000 ppm

One way to reduce levels of hazardous gases is to ventilate the manure storage area using a mechanical ventilation system that forces fresh air into the space, increasing the oxygen level and decreasing the levels of explosive and toxic gases. By using a specially designed positive-pressure mechanical forced-air ventilation system, you can reduce the buildup of dangerous levels of gas. Forcing fresh air through a fan into the storage area reduces the possibility of fire or explosion caused by explosive gas coming into contact with electric fan motors. Fans should be able to move a volume of air equal to one-half the volume of the empty manure storage area every minute. Use the ANSI/ASABE S607 standard, provided by the American National Standard Institute (ANSI) and American Society of Agricultural and Biological Engineers (ASABE), for guidance about ventilation capacity and ventilation time prior to entry and during occupancy. Click HERE for more information from Penn State Extension about the standard. To avoid the failure of a critical ventilation system during a power outage, connect the system to a standby power source that is regularly maintained and tested.

Entering Confined-Space Manure Storage Areas

If possible, avoid entering confined-space manure storage areas. If entry is unavoidable, you should fully understand the risks of entering such a space and have an entry plan that outlines your actions.

Complete the following steps when entering and working in a confined-space manure storage area:

  1. Test the oxygen and explosive and toxic gas levels from outside the manure storage area. 
  2. Prior to entry and during occupancy, use a positive-pressure ventilation system to ventilate the manure-storage area.
  3. Prior to entry, lock out all power sources other than the positive-pressure ventilation system to reduce the risk of stray electricity.
  4. Wear an adjustable body harness with a lifeline attached to a rescue and retrieval system and carry a portable gas monitor.
  5. Assign a second person to remain outside of the manure-storage area in case he or she must implement the rescue and retrieval system or get additional assistance.
  6. Maintain verbal and visual contact with the person outside the manure storage area. The person outside the storage area should not enter the area, even in the event of an emergency.
  7. Retest the air quality continuously during occupancy to monitor gas levels.

Additional Safety Recommendations

  • Remember that youth under the age of 16 are prohibited from working in confined spaces.
  • Post warning signs about the risks of confined spaces and gas hazards on or near all manure storage locations.
  • Instruct family members and employees about the hazards associated with manure storage in confined spaces. Even though most agricultural operations are not covered under OSHA regulations for confined-space entry, confined spaces exist in production agriculture, and it is vital that every person associated with the farm or ranch receive training on the hazards. 
  • Prepare and document an entry plan for confined-space manure storage areas. Inform family members and employees about the plan.
  • Provide annual training for family members and employees about the entry into and emergency procedures associated with confined manure storage spaces.
  • Restrict access to confined spaces to authorized individuals. Remove temporary access ladders, and restrict access to permanent ladders.
  • Be aware that personnel and animals may need to vacate the confinement building during manure storage agitation or pumping.
  • Prohibit smoking in and around manure storage areas.
  • Operate manure agitators below the surface of liquid manure to reduce the release of manure gases.

See the Penn State Extension video below to learn more about safety concerns associated with manure storage in confined spaces.

Use the following format to cite this article:

Confined space: Hazards of manure gases. (2012) Farm and Ranch eXtension in Safety and Health (FReSH) Community of Practice. Retrieved from http://www.extension.org/pages/63141/confined-spaces:-hazards-of-manure-….

Sources

Confined spaces. (n.d.) United States Department of Labor.  Retrieved from http://www.osha.gov/SLTC/confinedspaces/index.html.

Harshman, W., Yoder, A., Hilton, J., & Murphy, D. (2004) Confined spaces. HOSTA task sheet 3.8. National Safe Tractor and Machinery Operation Program. Retrieved from http://www.extension.org/sites/default/files/NSTMOP%20Task%20Sheets%20Se….

Harshman, W., Yoder, A., Hilton, J., & Murphy, D. (2004) Manure storage. HOSTA task sheet 3.11. National Safe Tractor and Machinery Operation Program. Retrieved from http://www.extension.org/sites/default/files/NSTMOP%20Task%20Sheets%20Se….

Steel, J., Murphy, D., & Manbeck, H. (2011) Confined space manure storage hazards. Penn State Extension. Retrieved from https://extension.psu.edu/confined-space-manure-storage-hazards.

Zhao, L. (2007) How to work safely around manure storage. Ohio State University Extension. No longer available online.

 
Reviewed and Summarized by:
Linda M. Fetzer, Pennsylvania State University – lmf8@psu.edu    
LaMar Grafft, East Carolina University – grafftl@ecu.edu
Davis E. Hill, Pennsylvania State University – deh27@psu.edu
Carol Jones, Oklahoma State University – jcarol@okstate.edu
Dennis J. Murphy, Pennsylvania State University – djm13@psu.edu          

J. Samuel Steel, Pennsylvania State University (Has since retired)