Employers, safety professionals and insurers are working to promote workplace safety as the fast-growing energy industry tries to stem fatalities among employees who work long hours while operating heavy machinery and vehicles.

Oil and gas extraction has produced millions of jobs across states such as Louisiana, North Dakota, Oklahoma and Texas in the past five years, but the economic boom also has brought a jump in work-related injuries and fatal accidents. An energy industry high of 142 fatalities was reported in 2012, according to the latest data available from U.S. Bureau of Labor Statistics.

Hydraulic fracturing or fracking, an oil and gas extraction technique, is “very high-hazard work,” said David Michaels, the U.S. Labor Department's assistant secretary of occupational safety and health in Washington. “It involves heights, it involves hydrocarbons coming out of the Earth at huge pressure, and probably the most hazardous component is the increased use of vehicles.”

Anytime an industry experiences a surge in fatalities, “you've got to look a little bit deeper,” said Woody Hill, vice president of safety services at Texas Mutual Insurance Co. in Austin. In taking a closer look, Mr. Hill said he found the number of fracking-related injuries in Texas was small compared with the rate and severity of vehicle-related accidents in the energy industry.

Inexperienced operators aren't used to driving water trucks, salt trucks or other types of vehicles that support a drilling operation, and driver fatigue is common among employees who are “working 12-, 13-, 14-hour shifts with overtime and ... are falling asleep at the wheel,” Mr. Hill said.

North Dakota reported the highest incidence work-related fatalities among states with an energy industry presence. In 2012, its fatality rate in the mining and oil and gas extraction sector was 104 deaths per 100,000 workers, six times the industry's national rate of 15.9, according to an AFL-CIO report released in May.

More than half of all workers who died in North Dakota in 2012 were killed in transportation-related accidents, said Eric Brooks, area director for the U.S. Occupational Safety and Health Administration in Bismarck, North Dakota. That, he said, has prompted state and local police as well as the North Dakota Department of Transportation to launch safe driving campaigns, he said.

BP P.L.C. has launched similar programs worldwide, including one that aims to increase safety awareness among the third-party drivers providing road transport services. Drivers are asked to sign and carry a safety partnership card and contact dispatch for help in the case of a safety risk, according to the company's website.

“Vehicle-related incidents remain one of the key risks facing our industry, so driving safety remains a high priority for us,” a BP spokesman in Chicago said.

There are similar initiatives in Texas, such as the Give Safety a Hand campaign that Texas Mutual launched with its partners in April 2013.

When the Austin, Texas-based insurer announced the campaign and workshops last year, Mr. Hill said Texas Mutual's claims found that driving-related accidents accounted for nearly 60% of oil and gas industry fatalities.

In addition to training workers on safe driving, some energy companies “have policies in place that preclude operators from driving after a shift,” he said. “They make accommodations close to where the job site is or where the work site is.”

Other employers stress situations where three or four workers ride together, “with the thought being that if you keep an operator in there with others it will help them stay awake and alert, but we haven't seen that to be the case,” Mr. Hill said. “You can train, train, train and have the most defensive driver, but if they've worked 20 hours and now they're driving three or four hours ... there's no amount of defensive driving that will fix that problem.”

Mr. Hill said he's also seen a number of fatal accidents in which workers weren't wearing seatbelts, which could be attributed to cultural differences in some cases, he said.

Other industry hazards include falls, being struck by equipment, electrical fires and explosions, experts said.

More oversight in the oil and gas extraction industry could reduce such accidents, said Peg Seminario, Washington-based director of safety and health at the AFL-CIO.

Unlike coal mining, which is regulated by the U.S. Mine Safety and Health Administration, “the oil and gas industry is largely unorganized,” Ms. Seminario said, adding that it's up to the industry to call for more controls.

“It's not as though OSHA and (the National Institute for Occupational Safety and Health) aren't doing anything,” she said. “They are. And it's not as though the industry isn't doing anything. They are. But clearly the situation is one that demands a higher level of attention because the status quo is not acceptable.”

There are only eight OSHA compliance officers covering North and South Dakota, according to the AFL-CIO report.

Because of limited resources in the field, Mr. Brooks, the OSHA official in North Dakota, said other regions often are called upon for “additional resources to make sure we respond appropriately.” The goal is to be on-site within one day of an incident, he said.

While OSHA does plan to increase the number of compliance officers in the Dakotas, “much of what we do is reactive inspections after someone is hurt or killed,” Mr. Michaels said. “The more important change we can make is to change the overall (safety) culture of the oil and gas industry and we're working very hard with NIOSH on that and with the industry as well.”

Mr. Hill said cultural change is more important than many people realize.

“If you care for people, you actively engage, you let your employees know that you think about them, you provide a safe work environment, people inherently will do the right thing and work safely,” Mr. Hill said.