Dangers of Silo Gases
- [Narrator] Silo gas can pose a dangerous threat to farm families and their employees.
In this video, we're gonna talk about what you need to know that can help reduce the risk of being exposed.
On the left, we have a conventional upright silo.
This silo is unloaded from the top by an unloading system that is suspended from the peak.
As the silage level gets lower, an individual is required to enter the silo and adjust the unloading system as needed.
This makes this silo especially dangerous because it increases the risk of a person being exposed to the gas.
On the right, we have an oxygen limiting silo.
It's also an upright silo, however this one's unloaded from the bottom.
It should never be entered because of the limited oxygen supply.
So what is silo gas?
It's also referred to as NO2, or Nitrogen Dioxide.
It's a natural by-product of forage fermentation, and can appear in high concentrations as a red, brown, and yellowish haze.
In low concentration, it can appear as a white or gray haze, which is often mistaken fro a silo fire.
It gives off a strong bleach-like odor, and is extremely toxic to humans and livestock.
Now that we know what silo gas is, let's talk about where it comes from.
The fermentation of silage produces Nitric Oxide.
This Nitric Oxide mixes with the O2 from the air to form NO2.
This gas formation peaks within two to four days, but the gas can linger in the silo if it's not exhausted or vented.
Several factors will influence the amount of gas that's produced in a silo.
The important thing to remember is that the more nitrates that are in the crop when it's harvested, will create more gas after it's stored.
Other influencing factors include the amount and type of fertilizer that's used, and of course the crop season, especially the weather, such as droughts followed by heavy rain before harvest, along with wet and cool temperatures during growing season.
Some things to keep in mind when dealing with silo gas is that it's extremely toxic and poses a great health hazard.
The first week after filling a silo is the most dangerous, and silo gas is heavier than air, so that means that it will sink.
Typically, it's found at the silage surface, or at the bottom of the feed chute where it can accumulate into a feed room, causing extremely dangerous conditions to employees or livestock that may be in the area.
To decrease your risk of exposure, avoid entering a silo for three weeks after filling.
Never work alone, always have someone standing by in case an emergency is to happen, and before entry, run the blower for 20 to 45 minutes and continue running the blower if you enter the silo.
Make sure that the blower is running at the appropriate silage height.
Some blowers are only effective in 15 feet of head space, which means if the distance between the silage surface and the top of the silo, where the fill pipe enters, is greater than 15 feet, it may not be effective.
If you're trained and it's available, use an SCBA, or Self Contained Breathing Apparatus, and gas monitoring equipment.
On the left, is what a typical gas meter may look like.
If using a gas meter, make sure that it is capable of monitoring Nitrogen Dioxide.
On the right is as chart that indicates the effects Nitrogen Dioxide has at particular parts per million.
At 50 parts per million, Nitrogen Dioxide is listed as an IDLH atmosphere, which means immediately danger to life and health.
If exposed to silo gas, seek proper medical attention immediately and find a medical professional that is trained in dealing with silo gas emergencies.
Low exposure to silo gas can result in discomfort and watering of eyes.
This should be an alarm to an individual and make them want to evacuate the area immediately.
Mild exposure consists of cough, congestion, and difficulty breathing.
Also during this time, fluid can start to develop in the lungs.
Higher exposure can result in sickness, chemical pneumonia, and can also result in death.