Worker exposed to silica dust while cutting concrete. (Getty Images)

Worker exposed to silica dust while cutting concrete. (Getty Images)

After years of inaction, the federal Occupational Safety and Health Administration is expected to unveil tomorrow tougher standards, widely opposed by industry, to protect workers from exposure to silica dust.

Commonly found in sand, concrete and stone, silica has long been recognized as a critical workplace hazard when pulverized into dust. Miners, stonecutters and other laborers who have inhaled the particles have suffered lung cancer as well as silicosis, a scarring of the lungs that can make breathing difficult.

In 1974, the National Institute for Occupational Safety and Health recommended that the exposure limit be dropped to 50 micrograms per cubic meter. For more than 40 years, OSHA didn’t act. That’s now expected to change.

OSHA’s new silica standard is expected not only to reduce the exposure limit for all workers to the NIOSH-recommended level, but also to require medical monitoring in some circumstances. OSHA estimates that more than 2 million workers are exposed to silica dust.

Since OSHA’s founding in 1971, the agency has enforced two sets of exposure limits for silica. For workers in general industry, the limit has been 100 micrograms of silica dust per cubic meter of air. For construction and shipyard workers, it has been 250 micrograms.

The new standard has been opposed by industry groups such as the U.S. Chamber of Commerce. Mark Ellis, president of the National Industrial Sand Association, said this week his group has urged OSHA to keep the exposure limit unchanged but require exposure monitoring and medical surveillance. He said the biggest problem with silica exposure is that employers aren’t complying with current standards.

“This is a 100 percent preventable disease,” Ellis said.

Exposure in New Occupations

Indeed, the death rate from silicosis has steadily dropped since 1968, although recent studies have discovered the potential for silica exposure in new occupations.

For example, hydraulic fracturing, or fracking, uses sand to prop open fissures in underground shale to access oil deposits. NIOSH collected air samples at 11 fracking sites in five states and found, at each site, silica samples that exceeded safety limits.

Workers who cut, grind and polish popular quartz countertops are also at risk. These engineered stone countertops may contain as much as 93 percent crystalline silica; granite slabs contain less than 45 percent. Dozens of countertop workers in Israel and Spain have contracted silicosis. The first case of an American countertop worker contracting the disease was reported in 2014.

“The problem of silica dust exposure has not gone away,” said Dr. Robert Harrison, clinical professor of medicine at the University of California, San Francisco. “This is not an old hazard. This is a current hazard,” he said.

OSHA spent years developing the new silica standard. In 2011, the agency sent the proposed rule to the White House’s Office of Management and Budget for review. Such reviews are supposed to take 90 days, but can be extended indefinitely. That one, however, lasted about 2½ years.

Subsequently, the agency held 14 days of public hearings on the proposed regulation and received more than 2,000 comments. In December, the agency sent a draft of the final silica standard back to the Office of Management of Budget. At the time, OSHA was planning to publish the silica rule last month, but that was again delayed, leading many to suspect that a new standard would never be established by the Obama Administration.

“I’ll believe it when I see it,” said occupational safety expert Celeste Monforton, when asked about the new silica standard last week. A former official with both OSHA and the federal Mine Safety and Health Administration, Monforton now teaches public health at George Washington University. She blamed the Obama Administration for dragging its feet on the regulation, but said it’s so rare for OSHA to put out a new regulation, “we should celebrate those victories when they occur.”

“It’s extremely significant,” she said.