Silos present on many farms and can pose significant farm workplace hazards. Potential accidents include falls, electrocution, entanglement in augers, and silo gas inhalation. Workers need to know safe operating procedures and what to do in the event of an incident. The key information on silo operation comes from the Silo Operator’s Manual. It provides instructions on safe operation that are essential for all workers to know. Warning signs of hazards should be placed on the silo.

Silo gases are particularly dangerous to workers. Silo gases are nitrogen dioxide (NO2) and carbon dioxide (CO2). They are created by the natural fermentation of chopped silage shortly after it is placed in the silo. NO2 is heavier than air and typically has an orange-to-yellow colour. Warning signs you are in the presence of NO2 are a bleach-like smell and burning in your nose, throat, and chest. Because it is heavier than air it can be found at the base of a recently filled silo. NO2 is especially dangerous because inhalation can result in instant death. CO2 fills the higher airspace of the silo and replaces the air. Silo gases escape from silos through chutes, cracks, and drains. The gases usually escape within 48 hours of filling the silo, but it can be prolonged for three weeks or even longer. It is recommended that workers stay out of the silo for three weeks after filling to avoid exposure to silo gases unless the worker is equipped with a self-contained breathing apparatus. Silo gases are fatal to birds, livestock, and humans. Workers exposed to silo gases need to receive immediate medical attention.

When silo gases might be present there are a number of safety steps to take. The worker entering the silo should wear a self-contained breathing apparatus. The silo hatch door close to the level of silage should be left open. Before entering, run the blower for at least 15 minutes and leave it running to keep the air moving.

In addition to silo gases, mold spores present a hazard to workers. Mold spores can be present in a silo as a result of spoiled hay or silage. They are dangerous because when inhaled they can irritate mouth and nose tissue to the point of hospitalization. Any time a worker is working around moldy hay or silage a fine filter respirator should be worn to avoid inhalation of spores. To avoid inhalation of mold spores, actions should be taken to prevent mold growth such as following proper filling and chopping techniques. The top layer of silage should be wet before moving anything to keep moldy dust from becoming airborne. Materials should be handled mechanically any time possible to keep the worker far away from dust.

There are also a number of general safety points that should be followed to keep the workplace safe:

• Keep silos off limits to unauthorized personnel
• Maintain silo ladders in good condition
• Follow lockout and tagout procedures
• Use a safety rope and harness when entering a silo
• Never enter a silo alone
• Wear an appropriate respirator when there is a chance that silo gases are present

Proper safety procedures and training are essential for workplaces with silos. Ensuring all necessary precautions are taken will protect workers and will allow your workplace to operate safely. The information provided above is a brief summary of silo safety and potential hazards.

Elite Agri Solutions has an online course available to train employees and operators in Confined Space Awareness, the course can be found here. Elite Agri Solutions offers workplace safety training and education on health and safety. We will ensure your workplace is safe and that you meet all mandatory requirements. Do not hesitate to contact us for more information on this service.

Sources:

http://silo.org/silo-safety/
https://nasdonline.org/static_content/documents/1776/d001741.pdf
http://www.omafra.gov.on.ca/english/crops/weather/silo-gas-alert.htm
https://www.wsps.ca/resource-hub/guides/silo-safety
https://ofa.on.ca/wp-content/uploads/2018/01/silo_gas_dangers.pdf