Silica Dust Compliance Guide | Concrete Construction Magazine

Beginning in September 2017, the U.S. Department of Labor’s Occupational Safety and Health Administration (OSHA) began enforcing its new Crystalline Silica Standard, which reduces the permissible exposure limit (PEL) of respirable crystalline silica from 250 micrograms to 50 over an 8-hour period.


But since the new policy went into effect, the reaction of many contractors has been confusion.


A recent article in the May-June 2018 issue of Concrete Construction Magazine titled “Silica Dust Compliance Guide” by Jim Rogers and Zack Zerndt discusses real world reactions to the new policy, equipment and resources in place to help contractors comply with the new policy, along with new medical requirements and how to get employees on board.


This new standard is designed to reduce the number of lung cancer, silicosis, chronic obstructive pulmonary and kidney disease cases caused by the inhalation of silica dust.


Curecrete fully endorses this new OSHA standard for silicate dust, and encourages all associates to learn in detail how to be compliant with the new standard and how best to protect the health of their valuable employees.


Rid your jobsite of dust before you get fined.


Nearly a century after hundreds of workers died while tunneling through a West Virginia mountain, the federal government issued a rule that punishes construction companies that don’t adequately protect employees against silicosis. Some people think regulation is long overdue; others are insulted by the implication that they don’t know how or won’t take care of their employees’ health. However, the primary reaction of contractors to the respirable crystalline silica (RCS) standard, which the Occupational Health and Safety Administration (OSHA) began enforcing on Sept. 23, 2017, is confusion.

“OSHA told us that if you’re sawing within 24 hours of placement, it’s still green and no water is needed; but we don’t agree,” says Dave Marino, concrete operations manager for Trucco Construction, a medium-sized contractor in Delaware, Ohio. “We typically saw curbs the following morning and when the weather is hot, the dust flies. Even in cooler temperatures, there’s a lot of dust.”

Victor Neura from 880 Construction in Valley City, Ohio, spent $1,800 on a vacuum that collected 2.5 gallons of dust cutting 12,000 square feet of concrete. “I swept and bagged up the rest and threw it in the truck. I don’t have a clue what to do with it, so I threw it in the shop dumpster. I went to OSHA’s website and got nothing but a bunch of technical data. That’s great if you’re a scientist, but they should know by now to keep it at a sixth-grade reading level for the rest of us.” (By the way: dumpster disposal is acceptable.)

Silicosis kills about 100 Americans every year. It’s caused by crystalline silica, a basic component of rock, soil, sand, granite, quartz, and other materials common to concrete mixes. Blasting, cutting, drilling, hammering, sanding, and grinding concrete generates microscopic flakes that settle on lung tissue and, over time, clog airways and cause cancer. The federal government has been trying to mitigate those health risks since 1938, after the Gauley Mountain tunnel disaster. In 1971, a year after President Nixon signed the Occupational Safety and Health Act, OSHA took the first step toward a national policy by issuing a permissible exposure level (PEL) – the top limit allowed – of 250 micrograms per cubic meter over an eight-hour time-weight average and launching a “special emphasis program.” That effort produced a framework employers were encouraged but not required to use.

Over the following decades, as people continued getting sick and dying, the agency worked with industry, unions, and the medical community to craft an enforceable regulatory program that virtually eliminates exposure to silica dust. The Crystalline Silica Rule: Construction (29 CFR 1926.1153) was developed and approved. Then, three months before it was scheduled to go live last June 23, the agency delayed enforcement to give contractors more time to prepare.

The new rule lowers the PEL to 50 micrograms per cubic meter over eight hours and created an action level – the point at which you must start monitoring air quality – of 25 micrograms per cubic meter. Fines range from $12,675 (maximum) the first time; repeated or willful violations can reach nearly $127,000. As of April 24, according to Bloomberg BNA reporter Bruce Rolfsen, OSHA had issued 116 violations. The highest fine was settled down to $6,929.

Should you be worried? Well, an inspector can show up any time, with or without notice; but there are too few of them to hang around a jobsite or even to visit every job. After President Trump took office, the agency lost 40 inspectors through attrition and made no new hires. They were 4% of OSHA’s workforce, which fell below 1,000 in October 2017.

More often than not, you’ll get a visit because an employee or member of the public complained. Inspectors also look for gross violations while out driving around. Roofing jobsites, for example, often receive visits because fall-protection violations are easy to spot. So are clouds of dust.

Whether or not OSHA shows up, though, it’s irresponsible to roll the dice on employee health.

What Does 50 Micrograms LOOK Like?

“If you can see or smell it, you’re already in trouble,” says Fred Wittenberg, a retired wastewater engineer who dealt with asbestos, lead paint, mold, mercury, and other hazardous materials over a 30-year career. “I’ve seen dry-cutting of pavements, one of which was at an intersection with a crowd of children just released from afternoon school, with total disregard to the clouds raised.”

Merely slapping on a respirator won’t cut it anymore. They’re effective, but only protect those wearing them. The dust is still airborne and can affect other workers at the jobsite or nearby people.

You could monitor the situation and take action when dust levels exceed 25 micrograms. Or, you can stop dust at the source by using what the new rules refer to as Table 1: a list of equipment that meets the agency’s design standards for containing or minimizing dust and what you must do to ensure equipment is used properly. If you’re correctly using equipment that’s listed in table, you’re in compliance.

For example, when operating a handheld grinder, the engineering control is a commercially available shroud and dust collection system. The work practice requirements state that when this operation is performed outdoors, there are no additional requirements. When performed indoors, there are no additional requirements for exposures under 4 hours, but workers exposed over 4 hours must use a respirator with an applied protection factor (APF) of 10. If you want to avoid using respirators, you could direct one crew member to operate the grinder for the first half of the day and another for the second half of the day.

Even if you use the table, though, you must write a silica compliance plan that lists what activities are taking place at the jobsite and what they’re doing to keep exposure below the 50-microgram PEL. That’s a new requirement.

Table 1 has been a major boon for manufacturers, who’ve been unveiling dust-extraction products over the last year or so. A wide range of tools, attachments, and vacuums is available in corded and battery-operated versions, including add-on attachments for existing tools as well as purpose-built tools such as hammer drills with hollow bits that extract dust from a hole during drilling. Contractors are spending $10,000 to $100,000 depending on company size. Before you plunk down cold, hard cash, make sure the equipment will meet your needs. In the Table 1 example explained earlier, the vacuum used with the grinder must provide at least 25 cubic feet per minute (CFM) of airflow per inch of grinding wheel diameter and be equipped with the proper filter and a filter-cleaning mechanism to prevent clogged.

“Last year, right before the law went into effect, I irrationally bought a vacuum,” says Jake Vice, whose Indianola, Iowa, company focuses on tear-out and replacement of flatwork. “I later found out it’s only rated for enough CFMs to work with a small Husqvarna early-entry saw and small grinders, which we don’t use that often.”

Contractors are also concerned about wet-sawing, which minimizes dust but raises other issues.

“To wet-saw curb or walkway, you basically have to add a worker to the operation,” says Marino. “Some architects are making designs with sawcuts. Laying out the cuts with chalk and then wet-sawing washes away your chalk lines, not to mention the slurry makes a mess and covers your layout.”

Vice Construction began hand-grooving after a materials-testing employee scolded a crew member who was dry-cutting (against owner Jake Vice’s advice) about 40 linear feet poured the day before. But, he says, “I know we’ll have situations where customers won’t want the hand-tooled joints because some think the large gaps can be hazardous. Or when concrete gets away from us on a 95-degree, 90%-humidity day.” He and his team are considering setting up a truck rigged with a water tank, pressure washer, generator, and wet vac. “We’d cut our control joints wet, sweep slurry into a pile, suck it up, and pressure wash what’s left behind.”

Slurry does not require disposal in a specially designated landfill.

New Medical Requirements

The new rule requires employers to offer medical exams—including chest X-rays and lung function tests—in person, by a doctor, every three years for workers who wear a respirator for 30 or more days a year. Contractors report this costs $500 to $1,000 per employee. Employers also must pay for the employee’s time when they’re getting medical exams.

Theoretically, Table 1 can alleviate much of this burden. If you don’t want to use it, though, you must monitor air quality and implement engineering controls if silica levels exceed the 25-microgram action limit. You’ll have to perform and document baseline testing to verify exposure level and include in your compliance plan what engineering controls and work practice controls you’ll use to mitigate exposure.

“If we’re cutting a couple miles of curb through a field, respirators should be sufficient; if we’re doing the same sawing in the city we’ll use water,” says Trucco Construction’s Marino. “No matter where we saw, the worker using the saw will have protection whether the concrete is considered green or not.”

You may be able to meet the standards with HEPA air scrubbers and modern vacuums. Rockerz Inc. Vice President Danny Montoney got the air-quality results his grinder and vacuum vendor conducted in 2007. When properly used, the 2007 equipment met 2017 requirements. The manufacturer has addressed actionable events (high dust) that occurred during bag changes in the 2007 testing by adding a Longopac, a bag cassette system made by Swedish manufacturer Paxxo. As a result, he says, “We’re changing out to this newly designed vacuum across all operations within the next six months and working on another design using a multiple-stage HEPA filtration vacuum system. But there will be times when you’ll need to have employees wear masks for brief periods for added protection.”

Getting Employees on Board

Buying new equipment is only half of the battle. Getting employees to follow new procedures is the other half. You’re required to train workers on silica hazards and how to limit their exposure, including your requirement to offer medical monitoring.

“We geared up by spending time in the classroom with some of the area’s larger construction firm’s safety officers and sought advice from tool manufacturers,” says Xan Deaton, superintendent at Bartels Construction Solutions in Matthews, N.C. “We quickly learned compliance meant more than stocking a trailer with the newest dustless saw shrouds, hollow drill bits, and fancy vacuums. Employee education and, more importantly, buy-in to new best-practices has led to compliance much more effectively than a new tool with too many hose connections. We comply with the new rules with day-to-day site management, building employee relationships, and safety training.”