At this point, the OSHA silica rules are forthcoming, what should you be doing to prepare?

  • Read the OSHA Small Entity Guide. Initially it is daunting – 103 pages, but much of it is specific to tasks from Table 1 and the full rules are within it, as well. Plus, they have pictures!
  • Identify tasks which could have silica exposures silica-grinding
  • Train employees, identify your “competent person(s)” – my suggestion is: Superintendents/Project Managers
    • Warn those on your projects: NO VISIBLE DUST on any tasks (cutting, finishing, dry sweeping, etc.)
  • Document activities with airborne silica exposures below 25 ug/m3
  • Identify possible solutions for overexposures
    • Verify airborne levels with personal air sampling
  • Start a process to log the number of days with (any) exposure – >30 is inclusion into medical
  • Find a medical provider that can have medical screen performed & with a B reader

*Thanks Andrew for the photos*


I was recently forwarded an article on a gentleman who won a large sum of money ($8.75 million) for an asbestos related disease. There are many people getting these types of settlements for similar exposures.

However, what is interesting, is the attorneys argued the company knew about asbestos in 1965, but the exposure occurred in the 1970’s. Keep in mind, the asbestos rules at OSHA didn’t come out until the 1970s as well. So, exposure occurred before the regulations were in effect.

So, they knew of the airborne hazard, but continued to exposure workers before there was a rule. Does this sound like any modern day issue?   –hint– silica?!

Nowadays with the public being uber-aware of “potential” airborne hazards (mold?), with information so readily available, with OSHA rules outdated (annotated Z1 tables), and others publishing health standards like ACGIH,….the lesson is: protect your employees.

I don’t think we should be arguing about the OSHA rules. Let’s use available information and science. “More Than Just A Number” (article published by AIHA, May 24, 2016).

asbestos snow

You’ve probably heard the Federal silica proposed-rule has moved in it’s next step towards being a promulgated-rule.

And, you’ve hopefully looked at my prior post about the positives and negatives of the rule. I am usually not in favor of more rules, but as a safety person, my overall opinion is the new rule would be good.

However, there is some opposition (EHS Today Summary Article) from a few industry groups and associations, including ARTBANAM, and the ACC in an article to plastic manufacturers. And just recently a lawsuit was filed to stop the rule. They have some good arguments, of which, I think the best are: THERE ARE ALREADY OVEREXPOSURES at the current PEL, and silica related deaths have been in decline for decades.

The ACGIH and NIOSH have been recommending lower airborne limits for years. If you are a construction firm, hopefully you already have (engineering & administrative) controls and respiratory protection in place. If not, the best time to start was yesterday, and the next best time is tomorrow.

cut off saw


It’s probably not a new disease, but there are more cases being discovered for type of cancer called, peritoneal mesothelioma. This cancer is found in the stomach, and is cause from eating asbestos (probably not on purpose, but through the body’s normal ability to capture particulates). They are calling this cancer the “third wave”, in addition to asbestosis and mesothelioma (in lungs).

The Center for Public Integrity released a video and article on a dramatic case, Kris Penny, on Dec 17, 2015. NPR picked it up and posted it here. Hopefully more people will be aware of this type of cancer and it can be better reported/diagnosed.

In a related article, from Newser, they suppose this type of cancer is from home exposures, rather than occupational. This information was based upon Australia’s Asbestos Safety & Eradication Agency‘s 2015 report.  They claim:

  • 40.64% (568) of people had exposures from non-occupational exposures (they are self reporting for the Australian registry).
  • 20% (280) of all registration of exposure were women.
  • 62.6% (876) of reported exposures were under the age of 49
  • The “third wave” of asbestos exposures will be from DIYs


asbestos reports

Unfortunately new exposures are still occuring, especially in developing countries. There is an effort to stop asbestos use in these countries, and you can join one group, Global Alliance Against Asbestos.

These pictures will come as no surprise. But, silica dust exposures (and nuisance dust) is an ongoing issue. Bottom line: if you have dust, you need to add some controls.

Platform of rock crusher (photo courtesy BP)
silica 5

Crusher operations (photo courtesy BP)silica 6

Grinding asphalt with a Bobcat (photo courtesy AH) silica 7

Question: During mixing of portland cement bags of material (or similar types), am I overexposed?

Maybe, likely. But, probably not to silica. Most manmade, off the shelf products do not contain free-silica, or respirable fraction of the dangerous parts of silica. However, there is overexposure to respirable and total dust. But, be forewarned, if the product has rocks in the material, these may contain silica and if you cut the cured product- you can release respirable silica.

So, best practice is to:

  • Use a product without silica (look for the warning on the SDS/MSDS, or bag)
  • Eliminate any visible dust by water control methods (misting) or use local exhaust ventilation
  • Don’t be dumb; stay upwind. Or, at least do the mixing away from others
  • Wear a respirator

mixing cement

**You really do not know which respirator to wear unless you have performed airborne exposure monitoring**

I’m still startled by how many construction companies have not started a hearing conservation program. However, I do know why: we don’t see a lot of worker’s compensation claims from this injury (we still see them, but not in the numbers we think we should).

Recently I was asked this question: My company is strictly a general contractor. We do not have field employees, only Superintendents, Estimators, Project Managers, Project Engineers, etc. Do we need a hearing program?

Here’s why I think you should start a hearing program:

Start one for risk prevention, maybe not for overexposure to noise.
Most hearing loss claims are around $20k, and the cost of a program is about $15/year/employee. And, in some states, if you are the last injurious employer, you have to prove you WEREN’T the cause of the loss. (So, do noise monitoring/dosimetry semi frequently)

Other reasons:
it set’s a good example for your subs – when your subcontractor is making noise, it’s hard to tell them they need to start a program when you don’t have one at your company.  Call it ‘credibility’.

you can roll it into your company’s total worker health (TWH) / health promotion/ wellness program – even if you aren’t required to have it. Wouldn’t it be nice if your company took steps to make sure you still have your hearing?

if you’re checking their hearing; and they have losses, you can intervene – this might be a big one for construction employees. How many construction workers have noisy tasks? Shooting, hunting, motorcycles, concerts, cutting wood, drag racing, mow their lawn? They may have hearing loss outside of work. If you’re monitoring their hearing, you can maybe influence their behavior while doing these activities.


Obviously starting a program can take time to manage, but there are mobile units which can provide most of the work. And, if you have a workforce above 50-70 employees, it might even make sense to purchase your own booth.

noisy job

NIOSH (and with the help from some other groups) released a document this last week titled, “Best Practice Engineering Control Guidelines to Control Worker Exposure to Respirable Crystalline Silica during Asphalt Pavement Milling”cold milling machine

The issue: These machines are used to remove asphalt roads. They have a drum with teeth on them that essentially chew up the road and asphalt. A lot of respirable silica is generated (based upon the amount of silica in the rocks). The drums get really hot so water is used to cool it.  However, it does not control the respirable silica dust.  I’ve written (or, maybe complained) about the issue here, in 2010. And, I was informed, some good people were working on it.

The solution: The quick summary is: add more water and ventilation. Not rocket science, right? However, after reading this document, it might be. There’s a lot of information and specifics on what worked, and what didn’t. It was almost too much detail, but I suppose if you have a $200k+ machine, it is worth the time to figure it out. Below are some details:

  • Case studies – adding water and increasing the pressure flow decreased airborne dust
  • Tracer gas studies for ventilation effectiveness
  • Checklists and flow rate controls
  • Diagrams for where to direct water

Another benefit was the documentation of other’s work. There are numerous references  (5 pages!) to scientific articles. I did not notice any cost to implement the recommended changes, and I am curious to know what adding the ventilation system might run. Overall the document is good.

Finally, if you hold-on and continue reading to Appendix C, let me know what that all-means.  🙂



I was asked to summarize my thoughts on the OSHA proposed silica rule (which is currently pending). I’ve done it before, but since it was for the ASSE’s Industrial Hygiene Practice Specialty, it seemed fitting to post it on this site as well.

Wondering what is happening with the OSHA crystalline silica rule? In aviation terms it’s called a holding pattern. This airplane may-or may not-land. And, it is anyone’s guess.

If you haven’t heard, Federal OSHA is proposing to reduce the airborne silica permissible exposure limit (PEL) to 50 µg/m³. It is difficult to say how much lower this new rule will be, since the current standard relies on a calculated formula to obtain the exposure limit. However, for rounding purposes, let’s just say it’s a 50% reduction in the PEL. This limit is the same at the NIOSH Recommended Limit but still above the ACGIH (2006) Threshold Limit Value of 25 µg/m³.

Over the last year my views on this rule haven’t changed much: It’s a mixed-bag. There are still overexposures to silica. However, will the new rule change behavior?

To show some of the contrast, let me explain. Overexposures to airborne crystalline silica are still occurring. However, silica deaths have continued to decrease over the recent past (without the new rule). But, will the small employers comply? Or just wait to be cited? There is rarely a perfect solution for all situations. I’d like to provide a perspective balance to both sides of the rule.

The obvious benefit to lowering the silica exposure limit will be to protect overexposures to silica. I believe the rule will accomplish this in a number of ways. Any new rule will generate increased awareness for the subject of silica. The new rule will drive OSHA compliance by both lowering the PEL and by compliance with their additional controls. This will drive changes and modification to industries. Innovation will be spurned for controls and the need to comply.  In turn, this will create more discussions on the topic, the solutions, and overall awareness.

The new rule will get closer to the ACGIH TLV and update the health standards. The original rule was from the 1970s. And, OSHA is on the prowl for ways to update their current PELs.

Health and safety consultants will have an occasion for additional revenue in training, air monitoring, recommending controls, and other opportunities.

The new rule allows for alternatives to sampling. Rather than air sampling, you can choose to “over protect” and assure employees are controlling silica exposures.  This is a great solution for short duration tasks where exposure monitoring is prohibitive (see Table 1 from OSHA’s Fact Sheet). They emphasize control measures for silica.

There are very few new products and control measures for mitigating silica exposure in industry. Technology has somewhat sidestepped innovating products for dust capture and control for concrete work. Hopefully new products will be created to control silica. If nothing else, maybe we will see frequent job safety analysis (JSA, JHA) as a common practice to control exposures.


However, there are notable weaknesses to the proposed rule. The obvious downside is employers are expected to spend money. This will be an additional cost to doing business. Money will be spent on citations, controls for silica, labor during the activities, and for consultants to verify exposures are below the PEL.

This new rule will also allow OSHA to issue citations easier.  There are many items in the new rule which are beyond merely lowering the exposure limit. I imagine compliance officers will cite for failure to implement controls, or other technical aspects, rather than measuring the airborne dust and finding overexposure. Look for more drive-by citations.

And, there will be more confusion. Remember explaining to people how to calculate the current PEL? Well, in the short term, it won’t get easier. Although the PEL will be a fixed amount, there will be other things to explain. And, remember all the OSHA rules for leaded paint? The new rule is similar in how it allows you to provide adequate PPE and controls for “interim” work without measuring airborne levels.  Imagine you are a smaller contractor employer. This will be confusing and a lot of background work in order to use a jackhammer for one small project.

And, analytically, the airborne levels attempting to be achieved are so low, they are at the laboratory detection limits. With laboratory I currently use, to reach the detectable minimum PEL you will need to sample for at least 80 minutes (200 Liters). There is some newer sampling equipment which makes these levels easier to achieve. But, guess what? That will cost more money.  In addition, contained in the rule are mention of specific medical evaluations and facilities for those with continued overexposures. There are not enough medical facilities to support the number of people who need them.


Overall, I believe the new silica rules will help reduce overexposures to silica. The increase in awareness across the US will bring more attention to the danger. Employers who are doing absolutely nothing to control silica will get caught, punished, and hopefully change their ways. For employers already in compliance, there will be a small, but manageable, learning curve. I also see many contractors using interim controls (Table 1) as a guide to easily protect employees on short tasks with high silica exposures.

To stay ahead of the curve, the AIHA has released (2013) a white paper for guidelines on skills & competencies in silica specific to construction. It is a great outline for training your employees. Another great resource for awareness and silica control measures is silica-safe.org. As a reminder, pre-task planning is still one of the best methods for health and safety.

 Here’s my sampling outfit.

my silica bag


Sorry for the delay in writing. I have had some personal and professional projects taking a lot of my spare time. I have been preparing to present at a couple local conferences on Industrial Hygiene in Construction. It is a good exercise for me to ponder what I should say to these audiences. Here are some takeaways:


My latest guess (subject to change, by even tomorrow) is the Federal OSHA rule for silica will be enacted.

“Why”, you say? …well:

  • Current administration would love to push it through
  • Yes. It’s still an issue in the construction world. Have you driven by a construction site lately?
  • Federal OSHA is also talking about updating the PELs…and this one (silica) is an easy one
  • When?  No idea.

Falls in Construction:

This one is huge. In a bad way. If you look at what kills the most in construction, it’s falls (inclusive of scaffolding, ladders, fall protection, etc.) They cost a lot too. Not just in the number of people killed, but the claims & recovery cost are high. And, near misses in construction are VERY common. For example, just two weeks ago: An 18 year old roofer apprentice was working on a roof.  He stepped onto a piece of drywall and would have fallen to a concrete slab 25 feet below. Luckily someone had moved a piece of equipment directly under where he fell. He only fell four feet and had no injuries.

Hierarchy of Controls:

Is anyone working with these anymore? Just kidding, sort of. But, we can do a better job in construction of:

  1. Engineering Controls first. Can we eliminate this hazard? Has anyone asked to substitute this product for a safer one?
  2. Administrative Controls second. There are ways and methods which we do things in construction. These are usually passed down from journeyman to apprentice. Overall, this is awesome. For example, we need to rethink why we place the rebar on the ground? Can we use saw horses? Better material handling would save a lot of injuries.
  3. PPE third. And as a last resort.

Personal Protective Equipment:

Oh boy. There is a lot of room for improvement here. The wrong equipment, worn incorrectly, not used enough, and damaged. I don’t have the answer for this, except we should create and encourage the best safety culture possible.  I think this helps construction to take pride in their work, and their (and their friend’s) safety.

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