MEC&F Expert Engineers : After several workers recently died while handling manure, interest is growing in easy-to-use, inexpensive gas monitors to warn workers when manure handling generates dangerous levels of hydrogen-sulfide gases.

Saturday, March 24, 2018

After several workers recently died while handling manure, interest is growing in easy-to-use, inexpensive gas monitors to warn workers when manure handling generates dangerous levels of hydrogen-sulfide gases.


Routine Testing of Hydrogen-sulfide Gas Monitors Critical to Safety


It is critical to routinely inspect and test low-cost gas monitors, like the one above, before using them during high-risk farm tasks. Photo courtesy of the University of Iowa.

Agriculture is one of the most dangerous occupations, both nationally and worldwide. Among its risks to workers are transportation incidents and exposures to pesticides and other dangerous chemicals.

An especially dangerous chemical is hydrogen-sulfide gas, which forms during the handling and processing of livestock manure. After several workers recently died while handling manure, interest is growing in easy-to-use, inexpensive gas monitors to warn workers when manure handling generates dangerous levels of hydrogen-sulfide gases. Many monitors are commercially available, but little information is available to help farmworkers select the right one or maintain it during long periods of use.

To address this issue, researchers in a NIOSH-funded study at the University of Iowa, in Iowa City, recently compared four commercially available monitors and published their findings in the Journal of Agricultural Safety and Health. The laboratory study simulated a year of use in a pig barn by exposing the monitors for 18 weeks to levels of hydrogen-sulfide gas comparable to those found in livestock operations.

Study findings showed that the performance of monitors that only sound an alarm decreased faster than that of monitors that both sound an alarm and display air concentrations of hydrogen-sulfide gas. Of particular concern was the failure of alarm-only monitors to sound an alarm in the presence of high gas levels, even when the monitors had not reached their expiration dates. Although the monitors that both sound alarms and display readings were more accurate in sounding alarms, their displays of gas levels were inaccurate in the presence of high levels.

These findings underscore the importance of inspecting and testing low-cost gas monitors before using them during high-risk tasks, including manure agitation, pumping, and pressure washing, according to the researchers. In addition, they advised the routine testing of all gas monitors, even in the absence of manufacturer’s recommendations, to ensure that they continue to work properly.

More information is available:
Evaluation of Low-cost Hydrogen Sulfide Monitors for Use in Livestock Production
In Livestock Production, Not All Gas Monitors are the Same
NIOSH: Agricultural Safety
NIOSH Extramural Research and Training Programs: Centers for Agricultural Safety and Health