Federal worker safety authorities last Friday issued a hazard alert for tank gauging with particular relevance for operators involved in shale oil handling and storage. The action follows fines levied against two oilfield service companies in Colorado involved in a worker’s death at an oil tank site in 2014.

The Occupational Safety and Health Administration (OSHA) and the National Institute for Occupational Safety and Health (NIOSH) issued recommendations (www.cdc.gov/niosh/docs/2016-108/default.html) aimed at protecting workers who manually gauge or sample hydrocarbon levels in storage tanks.

Earlier OSHA assessed $14,800 in fines to two companies — Greeley, CO-based DJ Basin Transport and Mesquite, TX-based Gibson Energy LLC — for their roles in fatally exposing a 57-year-old DJ Basin worker to toxic fumes from a storage tank.

With OSHA cutting the penalties in half with no explanation, DJ Basin was fined $5,000 and Gibson $9,800. Both had been slated for larger fines: $14,700 for Gibson and $8,400 for DJ Basin, both of which are oil-hauling companies.

The victim, John McNulty, who died June 24, 2014, became one of nine workers nationwide killed during the past five years (2010-2014) while tank gauging, which is a means to determine the volume of oil loaded, offloaded or stored at floating production, storage and offloading platforms, port terminals, storage tanks and transportation medium. McNulty had been working on a catwalk between two oil tanks when he died.

While the local forensics team made no significant toxicological findings, an investigation by federal health officials concluded that McNulty likely died after inhaling toxic vapors while measuring oil storage tanks.

(Industry sources note that the accuracy requirement of a tank gauging system varies from highly precise measurement of level, flow and temperature for custody transfer to simple level indications for operational and process control.)

OSHA cited the two companies for operating an unsafe workplace because workers opened tank hatches at the top, allegedly exposing themselves to toxic petroleum vapors without proper protection. A separate case against oil site operator Noble Energy Inc. is still open at OSHA.

“The expansion of the oil and gas extraction industry [particularly with the shale boom] has led to new opportunities, but also new risks for workers,” said NIOSH Director Dr. John Howard. “This joint alert highlights the importance of remaining vigilant about the safety and health of our nation’s workers as our nation changes and adapts to these new opportunities.”

The alert cites research from both NIOSH and OSHA showing that workers at oil/gas extraction sites may be exposed to very high concentrations of hydrocarbon gases and vapors when manually gauging or sampling production tanks. Workers also face the risk of fires or explosions from high concentrations of hydrocarbon gas and vapors.

Safety officials stress the hazardous composition of crude oil constituents, the volatile hydrocarbons (benzene, butane and propane), and the fact that shale oil can sometimes have higher levels of these compounds than conventional produced oil, although studies in some states such as North Dakota have disputed this (see Shale Daily, Aug. 5, 2014).

There is the theory, not accepted widely, that shale crude oil is more prone to explode in rail cars, and it is generally agreed that chemicals in crude tend to “bubble up” from the oil and collect at the top of storage tanks.