Source: http://enr.construction.com, April 30, 2014
By: Tony Illia
Construction is a risky business full of jobsite hazards, from life-threatening falls to blunt-trauma injuries, but more insidious dangers exist, such as crystalline silica inhalation, which can lead to a type of cancer known as pneumoconiosis. It’s what coal miners call black lung disease, where tiny airborne particles cause lesions and scarring on the lungs, gradually leaving workers unable to breathe.
Silicosis, its equally harmful cousin, currently affects 1.7 million workers annually, reports the Centers for Disease Control and Prevention (CDC). It is caused by breathing in one of earth’s most common minerals, silica, which becomes a corrosive inhalant from the cutting, sawing, grinding, drilling and crushing of stone, rock, concrete, brick, block, mortar and industrial sand.
In other words, the condition is associated with nearly every construction activity. Nicknamed “grinder’s asthma,” silicosis is progressive and irreversible, but also preventable.
The daily permissible exposure limits for quartz, the most common form of crystalline silica, is 250 micrograms per cu meter of air (µg/m3) for the construction industry. The rule hasn’t been updated since 1971, when the Occupational Safety and Health Administration (OSHA) was created. The federal agency is now updating the standard with a proposed 80% cut to construction crystalline silica exposure limits, lowering it to 50 µg/m3 and thereby saving nearly 700 lives and preventing 1,600 new cases of silicosis annually.
“Every year, many exposed workers not only lose their ability to work but also to breathe,” says David Michaels, OSHA assistant labor secretary. “This proposal is expected to prevent thousands of deaths from silicosis—an incurable and progressive disease—as well as lung cancer, other respiratory diseases and kidney disease.”
The proposed revisions, published Sept. 12 after two years of delay, also call for worker training, medical exams, record-keeping, written access control plans, mandatory respirators and dust controls.
The proposal entails exposure-monitoring action at 25 µg/m3. The stricter standard will affect 534,000 businesses, 90% of them in construction. Compliance will cost the industry $511 million annually, OSHA says, although the total benefits exceed $4 billion.
“The agency has admitted its failure to properly enforce the existing standard,” says Geoffrey G. Burr, vice president of government affairs with Associated Builders and Contractors, Washington, D.C. “The agency clearly missed an opportunity to take a cost-effective approach while still improving compliance and worker safety.”
The Construction Industry Safety Coalition (CISC), which represents 25 construction trade associations, believes the proposed new silica rule is “significantly flawed” and “rife with errors and inaccurate data.” There is a lack of “scientific explanation justifying the new exposure limits,” says the group, which considers the standard virtually impossible to measure accurately using existing technology. It may not ensure worker protection either. Dust masks are the last line of defense, scientists say.
“The agency has not met its burden of demonstrating that the proposal is technologically and economically feasible,” says CISC representative Bradford T. Hammock, an attorney with Jackson Lewis LLP, Reston, Va., who previously served as OSHA’s lead counsel for safety standards. “In addition, OSHA’s proposed ancillary provisions are unworkable in the construction environment.”
The coalition—made up of the Associated General Contractors, National Association of Home Builders, American Subcontractors Association and American Road and Transportation Builders Association, among others—notes that 1.5 million construction workers were omitted from the agency’s assessment of the affected work force.
It pegs compliance costs at least four times greater than OSHA’s estimate. The CISC, as a result, has requested that OSHA withdraw its proposed rule until industry concerns are met. Post-hearing comments are being accepted through July 18; a final rule date has yet to be issued.
“Every year this rule is delayed, another 60 workers will die,” says Margaret “Peg” Seminario, director of safety and health for the AFL-CIO. “That’s deaths. That’s not even looking at the numbers of workers who will become sick. We still have thousands of new cases of silicosis every year in this country.”
Implementation of the standard faces several hurdles, such as the weather, which can change silica exposure boundaries every time the wind blows. Multi-employer jobsites are another challenge because all workers aren’t necessarily under control of the contractor overseeing the area, says Kevin P. Turner, safety manager for Hunt Construction Group’s Indianapolis-based Eastern division.
“Unlike other health hazards that have been regulated by OSHA in the construction industry, [such as] asbestos and lead, silica is prevalent to a certain degree in almost every job on a construction site,” says Hammock. “It is part of what nearly all construction employers must deal with day in and day out in virtually every work task for every employee.”
Over the last decade, more tool suppliers have introduced dust-capturing controls, namely exhaust ventilation and wet methods for drills, chop saws, hammers and grinders. Once a retrofit, new dust extractors are often sold with many tools. They are more portable and accept a HEPA filter, but they are also more expensive. The filter eliminates the need for a vacuum hookup, while adding up to $250 to the cost of a tool. Hilti Inc., Tulsa, offers dust removers and vacs, wet and dry, for dozens of tools. The shrouds can double the cost of smaller tools, like grinders, but save money on cleanup, health benefits and compliance fines.
Dust Control Technology, Peoria, Ill., offers large solutions, too. The DustBoss machine atomizes water to ultra-fine droplets for greater particle attraction over a 280,000-sq-ft area. The DB-100 sprays water at 200 psi with droplets at 50 to 200 microns, oscillating 359˚ at 1/8 hp, with an adjustable angle height of -7˚ to 45˚. But it still may not be enough.
“While no visible dust is a lofty goal, it has no basis in reality in the construction environment,” says Kellie Vasquez, vice president of Holes Inc., Houston. “Rarely, if ever, will there be absolutely no visible dust emitted from a silica-generating activity with the use of wet methods or other engineering controls.”