By ANN ALLEN
Indiana Correspondent

AKRON, Ind. — Matt Doud remembers the September 2008 day well. He and his father, Jim, were trying to fill the silo but nothing seemed to be running the way it should.

“We were leveling off the top when the blower pipe plugged,” said Doud, 24. “I went up the silo to unplug it and to get the blower started so we could get the gas out. It started running, but not like usual because the gas was abnormally strong.

“I finally got it leveled off and started the unloader, but it just didn’t run right so I went back up the silo to try to fix it.”

Doud didn’t feel anything until he climbed down and went into the house to eat lunch: “When I sat down, I couldn’t breathe.”

Nevertheless, he drove himself to the doctor, only to discover the office was closed. Undaunted, he drove to the emergency room of Woodlawn Hospital in Rochester, where he quickly learned he had been overcome by silo gas, an odorless, colorless gas with a potentially lethal one-two punch that doesn’t claim as many victims as other farm accidents – but still poses a real hazard.

By that time, he had only half his normal lung capacity – the bottom half of his lungs were nonfunctioning. Admitted to the hospital on IV drips and hourly oxygen breathing treatments, he expected to be released in two or three days. When the oxygen was removed, however, all he could do was look at the doctor and gasp, “I can’t breathe.”

Finally, after more than a week in the hospital, he was released with prescriptions for a breathing machine to use for treatment after he’s around corn dust. He now wears a mask in the family’s dairy barn.

“They told me if I’d been in the silo any longer, they would have had to insert a breathing tube,” he said.

“We filled the silos the same way we have ever since 1972,” Jim Doud said. “The gases were really bad last year.”

What are silo gases?

Dennis Murphy of Pennsylvania State University, writing for the National Ag Safety Database, says silo gas is formed by the natural fermentation of chopped silage shortly after it is placed in the silo.
Although the intensity of silo gas is affected by the style of silo, it begins forming within hours of the material being ensiled and then reaches a peak after harvesting. After two weeks it is unlikely that more gas will be produced, although some hazards remain if the gas has not been able to escape the silo.

Farmers should take appropriate safety precautions (see list of recommendations). There have also been reports of livestock being killed from silo gas flowing down the chute and entering the barn. Provide good ventilation to the silo room to dissipate dense gases as they cascade out of the silo during fermentation.

If the silo adjoins a barn (or other building), use barn portable barn exhaust fans to blow air into the feed room to overcome some of this hazard. Barn air would then be expelled through the feed room, rather than the reverse.

A box duct connected over the inside of the fan and extending down to 150 millimeters above the feed room floor will ensure that the heavier-than-air silo gases are effectively removed. The bottom of the silo chute must be closed off so that the fan will draw air from the stable and not from the silo.

The Douds finished filling silo a few weeks ago, but this year there were a few changes. “Matt wanted to go up there again this year, but I wouldn’t let him,” Jim Doud said.

Matt Doud, who now has allergies and asthma that he didn’t have before, has just two words of advice for others: Be careful.