Industrial Hygiene in Construction

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 
• 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*

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, to make this easier, let’s just say it’s a 50% reduction in the PEL. This limit is the same at the NIOSH Recommended Limit and above the ACGIH Threshold Value of 25 µg/m³. Before I offer my opinion, you can state yours to OSHA here, and I’d recommend you do.

Benefits:

• Increase awareness by everyone (any news is good news for silica awareness)
• Further protect employees from overexposures
• Update the health standards. The original rule was from the 1970s.
• New products for the industry will be created to control silica, like this.
• Pretask planning (JSA, JHA) will become more common
• Consultant hygienists will get more $ to: train, air monitor, etc.
• Alternatives to sampling. This is written in the proposed rule.
  • Rather than air sampling, you can choose to “over protect” and assure employees have adequate PPE
  • This is great for short duration tasks where exposure monitoring is prohibitive (see Table 1. below from OSHA’s Fact Sheet)

Weakness:

• Employers will spend additional money:
  • on controls for silica
  • on labor during the activities
  • on consultants to verify you’re below the PEL
• OSHA will cite you easier
  • (my guess) is compliance officers will cite you for failure to implement controls, rather than measuring the airborne dust and finding overexposure
  • driveby citations. Look at some of my “caught on camera” overexposures. It is easy to see why this will be easy for OSHA to cite.
• More confusion
  • remember how you felt when you started working with leaded paint? Picture that again.
  • smaller contractors might be confused with the changes
• I’ve heard: the airborne levels trying to be achieved are so low, they are at the laboratory detection limits. (this is a bit beyond me, honestly, but it has to do with chemistry & analytical methods)

Overall, I think lowering the limit will reduce employee overexposures to silica. The increase in awareness across the US will bring more attention to the danger. Contractor employers who are doing absolutely nothing to control silica will get caught, punished, and hopefully change. For good-contractors out there, this will make it easier to explain to your subcontractors who are a little behind. I can see many contractors using Table 1 as a guide to easily protect employees on short tasks with high silica exposures.

Your thoughts? I’d love to hear them. Here is a NY Times Article perspective.

Many bridges and elevated highways have leaded paint. Lead and cadmium was (and sometimes still) added to paint for durability. Nowadays other heavy metals are used for durability. This particular bridge was near the coast and had already been repainted sometime in the past. Repainting requires the removal of the existing paint by sandblasting.  Since the bridge was previously  repainted with a non-leaded paint, in theory, there should not be any airborne levels of lead, or cadmium. However, I always find airborne levels of lead. Why?

The possibilities are:

• not all of the leaded paint was removed
• recycled blasting agent has trace amounts of lead
• and possibly there are still levels of lead in the new paint that is supposedly “non-lead”

I always ask the laboratory to analyze my air sample for lead, and cadmium. Lead is usually the main contaminant, but occasionally I find cadmium. I will sometimes also have the lab check for zinc and chromium.  The sandblasters wear hooded powered air supply respirators, coveralls, and ear protection while blasting. Some other time I’ll talk about the noise from that activity (it’s LOUD!) and the fall protection issues they face.

Lead is a hazard in two forms: 1. airborne and 2. ingestion- from the transfer of contaminated hands/clothing to being eaten. Hygiene on a lead project is essential to preventing these exposures. A good safety practice, by which to verify that lead is not being transferred is to obtain wipe samples at random (or not-so-random) locations. Lunchrooms, shower/change areas, and pickup trucks are some of my favorite “random” locations.

The views around the area weren’t bad either…