H2S is one of the gases produced by the anaerobic degradation of manure. The colorless gas, which smells like rotten eggs, can be detected at levels as low as two parts per billion and exposure at levels exceeding 100 parts per million can be life threatening.

Clint Pinder of Levitt Safety, a company that distributes occupational health and safety equipment and offers support services throughout Canada, was on hand last month (December 13-14, 2006) to address Manitoba Hog and Poultry Days in Winnipeg. He told those in attendance, “You can be overcome by the gases and people have been killed by H2S.”

Regular H2S Monitoring Recommended

Pinder recommends farmers should be monitoring, or having someone come on site and monitor, to see what their levels are. He recommends that farmers should be looking at increased ventilation if the H2S levels are getting into the harmful range. “It’s kind of a balance that you have to make, especially in the winter time, in the barns as far as your level of fresh air that you’re bringing in to exhaust H2S out but also you're going to have to pay to heat that air. What farmers have to do is find that balance between not bringing to much fresh air in and spending a lot of money on energy versus what their levels of H2S are.”

It would appear farmers are doing just that. Pinder estimates producer awareness of the dangers posed by hydrogen sulfide gas have increased by 75 to 80 percent over the past four years. He figures 75 percent of larger operations, such as LaBroquerie, Manitoba based Hytek Limited have some form of monitoring in place. He estimates, now that they are realizing the hazards of H2S, between 45 and 50 percent of private barns are now monitoring for H2S.

Hytek Takes Proactive Approach to H2S Training

“We are trying very hard to be proactive and so far we’ve been successful.” says Hytek assistant safety coordinator Christine Janzen. “There have been no reported incidences of hydrogen sulfide poisoning in our barns.”

She explains that Hytek has a general workplace health and safety policy on how to pull barn manure pit plugs safely. The policy specifies that it should be done in tandem, and what the best ways are to help a person should they be adversely affected by hydrogen sulfide gas. They also go through their barns periodically with a high quality H2S monitor to check levels during various seasons and in different areas of the barns.

As well Hytek employees responsible for pulling pits are required to take a hydrogen sulfide awareness course which is offered by Assiniboine Community College (ACC).

Assiniboine Community College Delivers H2S Training

ACC agricultural extension program coordinator Mary Petersen explains that the four to five hour course looks at what hydrogen sulfide gas is, where it’s created, how it’s created, what the properties of the gas are and how it affects humans.


She points out that hydrogen sulfide gas is a very clinging gas and most people don’t understand that. “As soon as there’s some movement or agitation of that manure, that gas can be released in high enough parts per million that it can knock someone down or it could even kill them.”

Prairie Swine Centre Conducts H2S Research and Delivers Awareness Training

The Saskatoon based Prairie Swine Centre has conducted several research projects designed to assess and reduce the risks of H2S and it offers hydrogen sulfide awareness training on a fee for service basis throughout western Canada, into Ontario and the Maritimes as well.

“Generally people are much more aware of their work environment now than they were ten years ago,” says Prairie Swine Centre information services manager Lee Whittington. “When we did sampling of barn air quality, about four ago, we were seeing some extremely high levels. If a person had spent any significant amount of time in that particular part of the barn where we saw that spike in hydrogen sulfide, they would have been seriously hurt.”

He acknowledges people go into barns every day and they’re not getting sick but says there is always that potential and that a lot more people are wearing small monitors now. “If the monitor does go off indicating that there are higher levels, they get the heck out of that environment and you’re back in in ten minutes when it’s dissipated.”

Similar to the ACC program, the H2S awareness program offered by the Prairie Swine Centre runs between four to four and a half hours covering such areas as properties of H2S, exposure limits, detection and the importance of Standard Operating Procedures and implementing an emergency response plan. It also includes demonstrations of H2S monitoring and safety equipment.

H2S Awareness Training Proves Effective in Changing Attitudes

Program instructor Shannon LaRoche agrees H2S awareness training appears to be working. “We’re seeing more awareness out there in the barns with management and with employees taking the courses.”

“We’re seeing that there are hydrogen sulfide monitors being used when liquid manure is being agitated within the barns systems or within the liquid manure companies. And we’re seeing self contained breathing apparatuses being purchased and in all the barn locations. It’s really a positive and encouraging thing that the course has brought about that awareness and that the industry is taking a proactive approach to providing the necessary safety equipment that needs to be there.”

Employees More Aware of Dangers Posed by H2S

Pinder has also noticed a substantial change in the level of the awareness of the risks associated with H2S exposure. “When we first started coming here [to Manitoba Hog and Poultry Days] four years ago people weren’t aware of what gases to monitor for, how to monitor those gases and what the harmful levels are. Now I’ve got customers coming up to the booth that actually know just as much more about it than I do and I’m able to get some good best practices from them to transfer over to other producers.”

More information on hydrogen sulfide awareness training can be obtained from any provincial pork producer organization, from the Prairie Swine Centre, at www.prairieswine.usask.ca or from Assiniboine Community College at www.public.assiniboine.net.

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