Last fall, livestock producers in Iowa, Illinois, and Wisconsin were alerted to the dangers of hydrogen sulfide gas following a series of cattle fatality incidents during manure handling activities. Hydrogen sulfide is an important manure pit gas, and it is released during agitation and manure pumping. Many livestock workers are familiar with the gas’s “rotten egg” odor.
[Photo: Dr. T. Renée Anthony]
Some producers are starting to wear low cost direct readying gas monitors to provide warning alarms when hydrogen sulfide gases are released and become dangerous to life and health. Hydrogen sulfide monitors are available from many manufacturers and are recommended for use during manure handling operations. Leaving the area when a gas monitor alarms can save lives.
Researchers at the University of Iowa compared the performance of four easy to use, low-cost hydrogen sulfide monitors in an article published in the Journal of Agricultural Safety and Health. Although each gas monitor had different features, all of the monitors had a low and high alarm to alert the user of dangerous hydrogen sulfide levels. In addition, all monitors were advertised as good for at least two-years in the field. The researchers tested each monitor’s performance over time, simulating what they might be exposed to over one year of use in a livestock environment.
All of these monitors showed signs of reduced performance as the study progressed. “When we exposed these monitors hydrogen sulfide at levels that would be seen on the farm, the time it took for the monitor to signal an alarm increased,” says Dr. T. Renée Anthony, assistant professor of occupational and environmental health at the University of Iowa College of Public Health. “This would be a problem if someone wearing the monitor was not warned of hazardous concentrations quickly.”
Not all manufacturers recommend performing bump tests on gas monitors. However, the results of this study recommend that you should. The “bump test” simply requires delivering a known concentration of gas to the monitor and then checking: Does the alarm go off? Does it alarm quickly (<15 seconds)? If the monitor displays a gas level – does it match the one on your gas bottle?
“Bump testing is important for workers who plan to perform high-risk activities like agitating or pumping manure and pressure washing,” says Dr. Anthony. “If your monitor doesn’t display the gas level, it is the only way to know if the sensor still able to detect hydrogen sulfide.”