Fracking Hazards Gaining Attention
Chemical exposures during flowback operations are the focus of research and new recommendations. The National Institute for Occupational Safety and Health says it has information suggesting at least four workers have died in the last four years at well sites in North Dakota and Montana.
“NIOSH learned about several worker fatalities associated with flowback operations through media reports, officials with OSHA, and members of the academic community,” according to the agency’s website. “While not all of these investigations are complete, available information suggests that these cases involved workers who were gauging flowback or production tanks or involved in transferring flowback fluids at the well site. Often these fatalities occurred when the workers were performing their duties alone.”
Flowback is described as process fluids from the wellbore that return to the surface and are collected after hydraulic fracturing. The hydraulic fracturing fluids originally pumped and other fluids that contain volatile hydrocarbons from the formation are collected and typically stored temporarily in tanks or other facilities. Liquid hydrocarbons from the separation process are routed to production tanks and the fluid levels in the flowback and production tanks are periodically checked by workers using handheld gauges through access hatches at the top of the tank.
“Hydrogen sulfide — sour gas — is well recognized as a toxic exposure hazard associated with oil and gas extraction and production,” according to the agency. “However, less recognized by many employers and workers is that many of the chemicals found in volatile hydrocarbons are acutely toxic at high concentrations.”
At high concentrations, volatile hydrocarbons can cause abnormal heart rhythms. At lower level exposure, they can irritate the eyes, breathing, and nervous system.
NIOSH is assessing the hazards. In the meantime, the agency recommends employers:
- Develop alternative tank gauging procedures so workers do not have to routinely open hatches on the tops of the tanks and manually gauge the level of liquid.
- Provide training to ensure flowback technicians, water haulers, and drivers understand the potential hazards and risks.
- Monitor workers to determine their exposure and consult with an occupational safety and health professional trained in industrial hygiene to ensure an appropriate sampling strategy is used.
- Ensure workers do not work alone in potentially hazardous areas.
- Use appropriate respiratory protection in areas where potentially high concentrations of volatile hydrocarbons can occur as an interim measure until engineering controls are implemented.
- Establish emergency procedures to provide medical response in the event of an incident.