In the wake of field studies from the National Institute for Occupational Safety and Health, the Occupational Safety and Health administration issued a hazard alert about exposure to airborne silica as a health hazard to workers conducting hydraulic fracturing operations.
Silica is used as a proppant in hydraulic fracturing to keep fissures open and allow oil or natural gas to escape from shale deposits after the well is injected with high pressure fluids that open up the fissures. The fine sand can accumulate in workers’ lungs to cause silicosis, a lung disease that inflames and scars lung tissue around trapped silica particles. Silicosis reduces lung capacity and has been linked to lung cancer and other respiratory diseases.
The hazard alert walks emplooyers and workers through a series of steps that can help prevent silicosis by reducing exposure to the hazardous dust.
“Hazardous exposures to silica can and must be prevented. It is important for employers and workers to understand the hazards associated with silica exposure in hydraulic fracturing operations and how to protect workers,” said David Michaels, assistant secretary of labor for occupational safety and health in a press statement.
The study that led to the hazard alert gathered 116 air samples from 11 fracking sites. The samples demonstrated exposure levels to workers greater than OSHA’s permissible exposure limit in nearly half of the samples. However, taken against NIOSH’s more stringent recommended exposure limit, 79 percent exceeded recommended levels.
“OSHA and NIOSH are committed to continuing to work with the industry and workers to find effective solutions to address these hazards.”
The hazard alert offers these suggestions to limit worker exposure to the hazard:
- Use an alternative proppant such as sintered bauxite, ceramics or resin-coated sand.
- Monitor the air to determine exposures.
- Improve existing engineering controls and safe work practices.
- Mandate capping of unused fill ports on sand movers.
- Reduce drop height between the sand transfer belt and T-belts and blender hoppers.
- Limit the number of workers and their time spent in areas of exposure (and consider doing dusty operations offsite).
- Apply fresh water to roads and around the well site to reduce the dust.
- Enclose points where dust gets released.
- Use enclosed cabs or booths.
- Use local exhaust ventilation.
- Replace transfer belts with screw augers on sand movers.
- Provide respiratory protection when needed.
- Provide training and information to workers about the hazards of silica and other chemicals.
- Consider medical monitoring for workers exposed to silica.