In a study done by the Prairie Swine Center, researchers evaluated worker exposure to H2S, a potentially deadly gas, while completing tasks such as pulling plugs or power washing rooms. Measurements were taken over two seasons in all parts of the barns, and in many instances, concentrations were many times higher than the recommended maximums. The concentration of H2S that a worker can be exposed to for 8 hours is 10 ppm and short-term exposure is 15 ppm. The findings showed that while plugs were pulled, the H2S concentrations, a meter from the floor and within a meter of the plug area, were high in many cases, sometimes exceeding the monitors which can go up to 1,000 ppm. The use of these monitors in buildings is recommended for worker safety.
Scientists at the Prairie Swine Center plan to develop a system that will allow workers to reduce their exposure to H2S. They will look at 3 different options, the first being a plug design that allows workers to pull the plug away from the plug area. The second will look at a water-based spraying system to see if H2S emissions can be controlled while the manure is pulled. The third option is to see if it is a feasible to retrofit a scraper system in an existing manure pit to be able to take the manure out of the barn on a daily basis but yet in a liquid form to see if H2S emissions can be controlled that way.