Introduction

The metal beryllium is an engineer’s dream: Lightweight yet strong, capable of handling harsh environments underwater and out in space.

It’s also a medical nightmare. Minute amounts of its dust and fumes can trigger a disabling, sometimes deadly lung disease. It can cause cancer, too.

The Occupational Safety and Health Administration said it will propose Thursday to sharply tighten the level of beryllium to which workers can be legally exposed, belatedly responding to decades of studies showing that the current OSHA limit does not protect people’s lungs.

“This proposal will save lives and help thousands of workers stay healthy and be more productive on the job,” Labor Secretary Thomas E. Perez said in a statement.

This is OSHA’s second attempt at a tougher beryllium standard. It proposed one in 1975, only to see it beaten back by the secretaries of energy and defense. Beryllium is a critical component in nuclear weapons, and both agencies argued at the time that the country’s national defense could be compromised by lowering exposures.

But the U.S. Department of Energy, which oversees the nation’s nuclear-weapons facilities, had a change of heart years ago. In 1999, it approved rules to require respirator use for its workers and its contractors’ employees when beryllium levels reached 0.2 micrograms per cubic meter of air — one-tenth of OSHA’s current limit, and less than the scrapped 1970s proposal, too.

OSHA’s newly proposed standard, which would apply to an estimated 35,000 workers in a variety of industries, would reduce the current 2-microgram limit for an eight-hour exposure to 0.2 micrograms. It would also mandate medical exams for exposed workers and set down other requirements.

Nearly 100 deaths and 50 serious illnesses could be prevented each year if the rule takes effect, OSHA said. Besides lung cancer, exposed workers risk getting lung-scarring chronic beryllium disease, which is triggered by an allergic reaction to the metal and can kill.

The country has compensated nearly 2,500 current or former nuclear weapons workers who developed chronic beryllium disease, according to OSHA. But the full toll is unclear; beryllium has also been used in products ranging from space telescopes to golf clubs to dental appliances. OSHA believes that about 245 people are diagnosed with chronic beryllium disease each year.

As far back as 1999, as the Energy Department was finalizing its rule, OSHA said it would update its beryllium requirements. Petitions that year and in 2001 from groups such as Public Citizen and the Paper, Allied-Industrial, Chemical and Energy Workers International Union urged speedy action. The delays since then are typical for OSHA, which blames long waits for health standards on the process imposed by Congress.

The requirements for issuing a single standard are “onerous and burdensome,” OSHA chief David Michaels said in an interview. Michaels said OSHA had completed some work on the beryllium proposal when he arrived in late 2009, and has prioritized it since then, but only recently cleared the final hurdles.

Industry opposition has played a role in health-standard delays. That’s part of the beryllium story, but in recent years, something unusual happened: Two bitter opponents during the 1970s fight — the nation’s primary beryllium product manufacturer and a major union — joined forces to write a model standard in hopes of seeing action.

Materion, once known as Brush Wellman, and the United Steelworkers sent their recommendations — including a 0.2-microgram limit — to OSHA in 2012. Michaels called the collaboration “a historic opportunity.” He hopes it spurs similar efforts in other sectors.

“If the industry and a union came to us and said, ‘We want to help you,’ it would certainly move things much more quickly and we would be able to save far more lives,” Michaels said.

Not all workers who could come into contact with beryllium are covered by the proposed rule. Some exposed to trace amounts in raw materials, such as construction workers using coal slag for abrasive blasting work, were left out. OSHA said it would seek comment on whether those workers should also be included. Michaels said the agency is particularly concerned about people working near blasting, who don’t have the respiratory protection that blasters are required to wear.

OSHA’s Advisory Committee on Construction Safety and Health recommended last year that construction workers be fully covered by the standard. Though it did not follow that suggestion, OSHA said it is seeking information to determine whether to include blasting operations in the standard.

The possibility of inclusion worries a major supplier of coal slag abrasives. The company, Harsco Corporation, met with the White House’s Office of Management and Budget last September, when that agency began vetting the proposed beryllium standard. Harsco said in a presentation that the construction industry “Should Not be Included in the Proposed Rule.”

Harsco, which declined to comment Wednesday because the proposal had not been issued yet, told the OMB that applying the proposed standard to construction would impose needless costs. Current OSHA rules sufficiently protect construction workers from beryllium in coal slag, the company said, disputing the results of a National Institute for Occupational Safety and Health study in 2007 that found beryllium above the current standard on one of two days that researchers sampled a blasting operation in Maryland.

Coal slag in blasting is one of the alternatives to silica, which can cause another type of deadly lung disease in workers exposed to its dust. OSHA hopes to finalize its silica standard — 40 years after starting down that road — by the end of 2016.