(800) 645-3475 questions@nilfisk.com

Why You Shouldn’t Fear OSHA’s New Silica Law: Advice from an Industrial Hygienist

OSHA’s new silica dust law is one of the hottest topics in the construction industry today. It’s discussed frequently at industry events and on message boards, it’s the topic that generates the most questions from our customers, and the silica dust-related content we’ve produced has been the best-performing content on our blog over the past year.

With construction season for much of the country just around the corner, we wanted to learn more about how construction companies and contractors are adapting to the new standard. To give us an on-the-ground perspective, we spoke with industrial hygienist Alexi Koltowicz from TriMedia Environmental & Engineering, a Michigan-based firm that provides a range of services, primarily for the construction and energy transport industries.

“A big scary law” that isn’t really

OSHA’s silica rule faced a good deal of opposition from industry stakeholders. According to Koltowicz, the main reason it generated such controversy isn’t because silica dust exposure limits are new (they aren’t), but because the old rule was so difficult to enforce that many regulators didn’t bother enforcing it at all. As a result, many construction companies didn’t do what they needed to do to become compliant.

“There have been silica regulations from OSHA for quite a long time,” Koltowicz says. “But the results of the analytical method required under the old rule were inconsistent. You could take a sample that ran for 8 hours and still not be certain that you would have obtained useable information.”

This is because the OSHA rules were written decades ago, and the old law was based on state-of-the-industry technologies of the time. “One of the big things the new regulation does is vastly simplifies the way exposure is determined based on a sample analysis,” Koltowicz says. “As one regulator explained it to me, the big difference between last year and this year is that now if he drives by a site and sees a cloud of dust, he knows he can get a good sample. It’s much more clear cut, which makes enforcement significantly easier.”

Because enforcement is so much easier, Koltowicz says that the regulation “looks like a big scary law that’s going to be almost impossible for construction companies to comply with.” But, this is an overstatement — Koltowicz doesn’t think compliance will be that difficult. “The rule looks more intimidating for basic construction than it truly is,” he says. “It’s a well-designed law that took into account the reality for contractors and construction companies — it all depends on whether they’re proactive about getting in compliance before construction season gets into full swing or if they wait until they get cited by OSHA.”

Understanding Table 1

“A lot of companies feel like compliance complicates their lives significantly and costs a lot of money,” Koltowicz says. “But this is a misconception. The key for construction companies and contractors is understanding Table 1.”

Table 1 is essentially a “safe harbor” provision for construction activities. It was one of the ways OSHA responded to industry concerns, and it’s the first time the agency has done something like this.

“OSHA took decades of objective scientific data about silica exposure and produced a set of guidelines around common construction tasks,” Koltowicz explains. “For example, if you use appropriate equipment and do a particular task for 4 hours outside, you’re automatically in compliance. If you do the same task for 8 hours or inside, you might need a respirator. Table 1 covers most of the work construction companies do. Because of this, realistically, most construction companies in most situations can meet the requirements without doing any dust testing.”

Equipment requirements under Table 1

As a whole, the silica rule, including Table 1, is heavily focused on using the appropriate equipment. Koltowicz notes that the equipment falls into two main categories:

  • Equipment that delivers water. When dust becomes airborne, you can use water to knock it down so people can’t inhale it. In this way, water acts as a dust suppressant.
  • Vacuum shrouds that go over equipment. These shrouds capture dust generated by the equipment (e.g., a drill bit or a knife blade) in a vacuum stream so that there’s no potential for exposure.

Water is a very effective dust suppressant, and Koltowicz says that most handheld equipment, like jackhammers and air-powered cut-off saws, have long come with a connection for a water hose to keep the blade cool and reduce dust. But water isn’t always practical, for example, when using electric machines or when using machines inside, which is when you need a vacuum shroud.

And the most important feature of the vacuum shroud is that it needs to be HEPA-filtered.

“The particle size we’re worried about with silica exposure is roughly 4 microns in diameter and smaller,” Koltowicz says. “For comparison, the average human hair is about 100 microns and we stop being able to see things at about 20 microns. So, we’re talking about very small particles, much below our visibility threshold. Imagine if you sucked those particles up in a vacuum that didn’t have a filter that could stop them. You wouldn’t be reducing that material — instead, you’d be sucking it up, stirring it around, and ejecting it back into the air. That’s where HEPA filtration comes in. Certified HEPA filters are 99.97% effective at filtering particles that are 0.3 microns or bigger. They effectively stop everything.”

What to look for in a HEPA-filtered vacuum

Table 1 identifies several tasks where HEPA-filtered vacuums are required. Unfortunately, not all HEPA-filtered vacuums are created equal.

Koltowicz says that one of his biggest fears is that companies, particularly small contractors, will try to save money on their vacuum equipment and end up exposing their workers to even greater risk. “It’s easy to find vacuums labeled HEPA, but they aren’t really HEPA-filtered because the air isn’t going through the filter,” he says. “If you’re not appropriately filtering the air, you’re probably making the situation for employee exposure worse than if you hadn’t used the vacuum at all.”

Here’s what to look for to ensure your HEPA-filtered vacuum will do its job effectively:

  • Tight seals. The lid and the power head need to be tightly sealed to the canister. Otherwise, the air will go around the HEPA filter, rather than through it. “Like water, air wants to take the path of least resistance,” Koltowicz says. “So, you can put a HEPA filter on a vacuum, but if it isn’t sealed properly, then the air will find another way to escape. All air that enters the vacuum cleaner must go through the HEPA filter. If it can exit any other way, it will, which means it won’t be filtered at all.”
  • Solid HEPA filter housing. Make sure the HEPA filter seats into its housing in a way such that it can’t be bent out of shape or pushed around by air forces, which can provide another route for the air.
  • Pre-filtration. The vacuum should have a pre-filter to capture large particles before they reach the HEPA filter. Many vacuums use a canister, but Koltowicz notes that most good vacuums also use a paper bag. This pre-filtration keeps the HEPA filter from becoming clogged by large particles.

Learn more about multi-stage filtration for industrial vacuums.

Cyclonic pre-filtration vs automated filter cleaning

As with any new regulation, some things don’t become entirely clear until after enforcement begins. For the silica rule, one of these things is the requirement for cyclonic pre-filtration versus automated filter cleaning.

Cyclonic pre-filtration and automated filter cleaning accomplish the same objective: prolonging the life of the HEPA filter by keeping it from getting clogged. The difference is how the technologies work:

  • In vacuums with cyclonic pre-filtration, the air moves in a cyclonic action through a canister. As it spins, the larger particles drop down to the bottom. In this way, they’re removed from the airflow before the air reaches the HEPA filter.
  • In vacuums that employ automated filter cleaning, at some predetermined point, the vacuum will reverse the airflow direction so that rather than running as a vacuum it blows high-pressure air backward to clean the filter.

Both of these methods are called out in Table 1 as required during different tasks. In some cases the rule says either method is acceptable, while in others it specifies automated filter cleaning.

Koltowicz says that it’s currently unknown whether this will be a compliance sticking point, meaning if regulators will enforce the filter-cleaning requirement or if they’ll accept cyclonic pre-filtration. In fact, he has put in an official request with Michigan OSHA to clarify this point. If regulators will accept cyclonic filtration, it will be advantageous for the industry — of the two, automated filter cleaning technology is more expensive.

The bottom line: Compliance is not as difficult or expensive as it seems

While the law may look big and scary (read: difficult and expensive), Koltowicz believes that with the right consultant and the right equipment, it will actually be easy to comply.

After all, everyone in the industry knew that this was coming for a long time, and they knew the direction it was going. As a result, the majority of construction equipment sold today is already equipped with connections for water hoses and vacuum shrouds. Koltowicz notes that compliance may require construction companies and contractors to purchase new equipment, but since equipment in this industry has a fairly short lifetime, those purchases would likely need to be made anyway.

In fact, because of Table 1, much of the compliance activities that most companies will need to do are organizational. As such, they’ll cost less than many people fear (and much less than getting cited by OSHA). “I think I can get most contractors and construction companies into compliance — by guiding them through the compliance process and writing exposure control plans — for less that it would cost to hire an industrial hygienist to take dust samples for a day,” Koltowicz says.

To learn more about vacuum shrouds and other solutions for the construction industry, contact us. If you need additional help, such as with writing your exposure control plan, don’t hesitate to reach out to Koltowicz and the rest of the team at TriMedia.