Mines Face New Hurdles in Protecting Workers From Silica Dust

Tougher federal limits on miners’ exposure to toxic silica dust are creating a slew of compliance challenges for mine operators, from new air sampling and notice requirements to medical monitoring mandates.

About 1,100 coal mines in the US have one year to comply with the Mine Safety and Health Administration’s recently finalized rule, which calls for all underground and surface mines to reduce the amount of breathable silica dust by 50%. More than 11,000 non-coal mines like copper quarries and gravel pits have two years to get up to speed.

“I would not be surprised that when the compliance date comes around MSHA will be enforcing it—aggressively,” said Zachary Byers, an associate with Ogletree Deakins in Washington.

When inhaled, silica dust can scar workers’ lungs, leading to the disease silicosis that makes it difficult to breathe. In severe cases, patients need lung transplants to recover. A rise in the number of miners with Black Lung and other respiratory diseases prompted the new regulation, which would cover more than 200,000 workers.

Under the rule, the “permissible exposure limit” would drop from 100 micrograms of silica per cubic meter of air (100 μg/m3) to 50 micrograms during a work shift. Employers would have to start taking some protective measures where silica levels reached 25 micrograms.

Mine operators will need to set up dust reduction programs approved by MSHA and prove they’ve met the agency’s silica limits by taking regular air samples, said Adele Abrams of the Law Office of Adele L. Abrams PC in Beltsville, Md. The operators will also have to establish medical testing programs for workers to detect lung problems.

These and other changes may be particularly burdensome for smaller mine operators, attorneys said.

“A lot of small miners are going to have a pretty good shock to the system,” said Nicholas Scala, chair of Conn Maciel Carey LLP’s MSHA practice group in Columbus, Ohio.

Air Sampling

While coal mines already have dust sampling programs to comply with the agency’s coal dust regulations, mines that dig out other types of rocks and minerals will have to set up their programs from scratch.

If tests show silica amounts between the action level of 25 micrograms and the permissible exposure level of 50 micrograms, the mine operator must take new samples every three months, the rule says.

The required sampling can end if two consecutive tests find amounts below the action level.

If silica levels are above the permissible exposure limit, the mine operator must take immediate actions to lower exposure, such as the temporary use of respirators.

Respirators Discouraged

Although respirator use can’t be a long-term solution underground or above ground, the rule requires mines to have a written respiratory protection program that complies with ASTM International consensus standards.

“A lot of the concerns about the respirators is that it’s hard to wear a facemask when you’re underground and you’re in a tight space and it’s hot,” said Byers of Ogletree Deakins. “But those same concerns don’t necessarily apply when you’re dealing with an above-ground cement plant.”

Permanent corrective measures must be made, such as improving ventilation or using water sprays to reduce dust, the rule says. Frequent sampling is required until the level doesn’t exceed the exposure limit.

The new rule prohibits mines from using data from samples taken prior to the upcoming compliance deadlines a year or two from now.

“There’s no reason to ignore sampling results and a history of sampling,” said Brian Hendrix, a partner with Husch Blackwell LLP in Washington.

Notice Requirement

MSHA requires mine operators to notify the agency any time air sampling shows levels above the permissible exposure limit.

The notification mandate essentially requires mine operators to self-report possible violations and open the mines to inspections and citations.

Scala pointed out that the MSHA notification mandate wasn’t part of the agency’s rule proposal and was added after hearings and public comments.

Employers may challenge the notification mandate on the grounds that the change was significant enough to require a public comment period, Scala said.

Medical Monitoring

Employers must also set up medical monitoring programs to determine if workers are showing lung diseases symptoms attributable to silica.

Coal mines already are required to offer free medical monitoring, so the new rule impacts non-coal operations, especially small mines without in-house medical expertise.

“We have five-person mining companies that now have to have an industrial hygiene regime,” Abrams said.

The rule says each employer must offer its miners a free, voluntary medical exam that could include a chest X-ray to detect lung problems, and then offer follow-up exams roughly every five years.

Results of the X-rays will also be shared with the US National Institute for Occupational Safety and Health, which already collects coal miner data.

In the long-term, the examination results could be used to justify an ill miner’s request to be moved to a task without silica exposure, a process known as “medical removal.”

The current rule doesn’t include a medical removal option, but MSHA said it will consider transfers for medical reasons in a follow-up rule.

According to the rule, MSHA concluded that a medical removal rule would benefit from additional notice and comment on several issues, including protecting miners’ privacy, job benefits, and what area of the mine the miner would be transferred to.

The agency added that a determination should be made about whether NIOSH, the occupational health division of the Centers for Disease Control and Prevention, must make the removal determination.