CONSUMED BY FUMESHAZARDS OF AGRICULTURAL GASES

Learning Objectives

• Understanding the types of respiratory hazards• Identifying hazardous atmospheres

– Manure Pits– Silos

• Measuring Gases

Respiratory Hazards

• Three categories:– Particulate contaminants

• Dusts, Mist, Fumes 

– Gases and vapors• Chemicals

– Oxygen-deficient atmosphere 

Hazardous Atmospheres

• Can Be:– Flammable– Asphyxiating– Toxic

• Hazardous Environments on the Farm– Silos– Manure pits

Manure Pits

• Enclosed structures – Near or below an animal house

facility or open structures

• 75 fatalities from 1975 – 2004• Most of these fatalities

resulted from asphyxiation• Rescuers account for over

60% of confined space fatalities

Manure Pit Gases

• Hydrogen Sulfide– Greatest danger with enclosed pits– Rotten egg smell but higher concentrations

deaden the sense of smell– Collects in lower levels of structures– Released when manure is agitated– Levels of 500 ppm or greater can cause

death

Manure Pit Gases

• Ammonia – Non-toxic and heavier than air– Distinctive Sharp Odor– Can irritate the eyes and throat– Higher concentrations can cause

wheezing and shortness of breath– Less of an immediate concern because

the strong persistent odor discourages long contact

Manure Pit Gases

• Methane– Non-toxic and lighter than air

• Odorless, colorless• Forms explosive concentrations in air• When ventilation is inadequate can displace

oxygen and cause asphyxiation

Manure Pit Gases

• Carbon Dioxide– Non-toxic and heavier than air

• Odorless, colorless• Normal product of decomposition and

animal respiration• When ventilation is inadequate can displace

oxygen and cause asphyxiation

Decreasing the Risk of Exposure

• Ventilation– Force fresh air into the space– Use fans

• Never enter the space unless necessary– Always test gas levels– Wear harness and safety gear– Make sure another individual is with you outside the pit

Conventional Silos

• Structure– Concrete Staves held together by steal

hoops– Also reinforced with concrete, steel and

other materials

• Nitrogen is most abundant gas– Bleach like odor– Low lying yellow, red, or dark brown fumes– Settles at the top of the silage, flows down

the chute, collects in adjoining structures– Forms within hours after forges are ensiled

Oxygen Limiting Silos

• Structure– Constructed of a dark blue or green enamel coated steel– Also made of poured reinforced concrete– Designed so entry is unnecessary

• Fermentation produces both Nitrogen Dioxide and Carbon Dioxide– CO2 is odorless and colorless – When levels are high, individuals can be overcome quickly

Decreasing the Risk of Exposure

• Proper Ventilation– Keep Doors Closed– Use Fans

• Timing– Avoid Silos during critical periods

• 12 and 72 hours after filling• If possible two to three weeks after filling

– If you do have to enter wear a self contained breathing apparatus, and maintain visual contact with a second person outside

• Personnel• Personal Protective Equipment• Signage

Gas and Vapor Sampling

• Detector Tubes• Diffusion Tubes• Electronic reading instruments

Benefits of Detector Tubes

• Shows results in a minute• “Grab Sample”

– High concentrations that need immediate readings– H2S or NH3 in manure pits– CO poisoning

Photo: GMS Instruments

Photo: Terra Universal

Diffusion Tubes

• Direct reading measure– Takes hours to get reading

• Do not use in IDLH concentrations(Immediately Dangerous to Life & Health)

Photo: Grainger

Protection and Safety: Electronic Reading Instruments

• Instantaneous readings• Accurate to the concentration• Can be expensive

Summary

• Not all environments on the farm are safe.• Gases can overcome those exposed very quickly.• Ensure that you and your fellow workers are

trained on proper safety techniques.• Know how to test and monitor gases so you are

safe at all times.

References

• Dangers of silo gases. (2012) Farm and Ranch eXtension in Safety and Health (FReSH) Community of Practice. Retrieved from http://www.extension.org/pages/64390/dangers-of-silo-gases.

• Manure Storage Safety– http://www.extension.org/pages/19943/manure-storage-

safety#.UoY8lI154iU

• Respiratory Protection– http://www.extension.org/pages/63440/respiratory-protection-on-the-farm-

and-ranch#.Up41UY155is

For More Information

OSU Ag Safety & Health

The Ohio State University

Ag Engineering Building

590 Woody Hayes Drive

Columbus, Ohio 43210-1057

Email: jepsen.4@osu.edu

Phone: 614-292-6008

Website: agsafety.osu.edu

This project was supported by the USDA’s National Institute of Food

and Agriculture (NIFA) Rural Health and Safety Education Grant

Program- grant number 2012-46100-20144.