The Ontario Ministry of Agriculture and Food issued the warning after two reports of farm workers being injured by the gas -- formed when dry silage corn is exposed to heavy moisture -- as wet weather came to the agricultural belt last week, the London (Ontario) Free Press reported.
The surge in moisture creates nitrogen dioxide from the corn, which when inhaled becomes burning nitric acid. The lungs then begin to fill quickly with fluid and the victim drowns on his own fluids, the report said.
The ministry said the nitrogen dioxide gas is heavier than air and seeps down to ground level in the first 12 to 60 hours after a silo has been filled. It said the gas sometimes has a brownish hue and often smells like bleach.
Officials urged farmers to wear a breathing apparatus and run ventilating fans for 30 minutes before starting work on the silos.
The summer drought affected many crops, but not to the extent it did in the central United States, where corn and other crops were withered months ago by a lack of rain.
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