October 5, 2023

NIOSH Recommends Training, Policy Improvements to Protect Railway Inspectors from Hazardous Materials Exposures

A new health hazard evaluation (HHE) report available from NIOSH describes visits by agency personnel to railyards in the Midwest United States to observe the work practices in place for inspections of railway shipping containers. A union representative had suggested that hazmat inspectors use 4-gas meters to evaluate the air around tank cars before beginning their inspections, but NIOSH found that the devices would not reduce the risk of hazmat exposure. Instead, NIOSH recommended increased training in hazard communication, anticipating the types of hazardous materials with which the inspectors may come into contact, and preplanning emergency response scenarios.

The visits were conducted in 2022 after NIOSH received a request from a branch of the American Federation of Government Employees. Previous incidents had resulted in exposures of inspectors to methylene diphenyl diisocyanate, methyl isobutyl carbinol, and anhydrous ammonia.

Agency personnel observed inspections of railway tank cars and intermodal shipping containers that contained butadiene, chlorine, hydrochloric acid, and many other hazardous materials. The inspectors were often required to climb on top of tank cars and open housings to evaluate the condition of valves. Inspectors were generally careful to stand upwind of the housing and to wait 15 to 20 seconds after opening to allow vapors to dissipate. In one instance, a valve threading had been stripped, resulting in exposure of the inspector to hazardous vapors. Cars that contained inhalation hazards were not always clearly labeled.

The use of 4-gas meters did not prove useful in this context, according to the NIOSH report. These devices can detect oxygen, carbon monoxide, hydrogen sulfide, and lower explosive limit concentrations, but they are typically used for entering confined spaces. In the open air at the top of tank cars, substances were likely to become so diluted that they would not be detected even when present. Some inspectors wore a 4-gas meter with a photoionization detector, or PID, which detects certain volatile organic compounds, but NIOSH personnel observed that the alarms on the instruments did not sound even in the presence of a noticeable leak of ethanol.

The NIOSH report notes no device can detect every type of hazardous material to which an inspector may be exposed. Other limitations related to these devices include potential false readings when used in certain weather conditions. For these reasons, the agency concluded that “carrying the device would add to the [inspector’s] burden and could provide a false sense of security.”

For more information, read the HHE report (PDF) on the NIOSH website.