Industrial Hygiene in Construction

As I have said in an earlier post, some OSHA, EPA, and MSHA rules are a good fit. They blend well with health research, scientific technology, good practices, and a low-cost-of-compliance for employers. Other rules are just bad. They are  totally out of date, not protective enough, or just not feasible/practical. Here’s my plug for a good safety manager/industrial hygienist – A good one will know which rules/guidelines to follow.

The New York Times (July 19, 2012, Cara Buckley) recently wrote an article on the US noise standards which are not protective enough for employees. In construction we also have three additional problems.

1. hearing loss is expected (or at least assumed in certain fields – carpenters, sheetmetal, ironworkers, etc.) and,
2. work shifts are usually over 8-hours. Noise exposure is usually calculated on an 8-hour time weighted average. During the busy months, an 8-hour work day is rare. It’s at least 10, maybe 12-14 hours. This doesn’t allow your ears to “rest” between shifts. For more information on extended work shifts go here.
3. extracurricular activities contribute to overall hearing loss – my point is that most construction workers don’t sit at home at the end of their shift. Almost everyone I know in construction is involved in one of these activities: hunting, shooting, motorcycles, water sports, yard work, cars, wood working/cutting, concerts, music, etc. Each of these activities contribute to their overall hearing loss, and again, doesn’t allow your ears to “rest”.

…which reminds me that I need to keep a set of ear plugs in my motorcycle jacket.

Are you measuring for zero accidents? Is this even possible? I agree it is a worthy goal. But, if you are presenting this to management, can you actually achieve it?

There is plenty of discussion around this issue. Maybe a better goal is something harder to measure, but more successful/beneficial in the long term. What about measuring one of these? (or a combination)

• response time from complaint to resolution (from employees)
• number of requests for safety related issues
• satisfaction of safety by workers (rate 1-10)
• safety committee interest & interaction
• decrease in airborne exposure levels year over year
• keeping track of engineering/administrative controls put in place per year

My 2 cents.

Occasionally (actually, far too often), I hear from a subcontractor who was told by the General Contractor (or owner) there is no asbestos onsite. Then, after they have been working for a month they find out it actually IS asbestos, and they were disturbing it. What do you do?

The first thing to do is stop work. Do not try to clean it up. Call an abatement contractor. They will identify the asbestos onsite, clean it up, and provide an airborne clearance test.

Next, you will need to provide awareness training (or better, let the abatement company provide it). Ideally this will occur on the day you start back working. Train everyone onsite about asbestos.

Finally, you (as the safety manager), need to identify and characterize the exposure to the employees. It should probably be a formal letter written to the owner, general contractor and employees.

Here are some tips on writing the letter:

• include employee names, work hours, type of work, PPE worn, and locations they were working
• describe the asbestos. Amount found, locations, type, estimated amount disturbed.
• describe remedy process and steps taken. Names of GC, owner, abatement company, airborne levels found. Who was trained afterwards.
• describe how things will change in the future. Here’s a tip:  any building before 1985 WILL have a building survey performed for asbestos….in writing.

Really, one exposure to asbestos is probably* not enough to contract a disease (asbestosis, or mesothelioma). It will take 15-30 years for symptoms to appear. But, it might be worth the “goodwill” to send affected employees into a occupational health doctor for a check up. The physician will reassure the employee and may provide some comfort.

*asbestos is a carcinogen. Greater exposure = greater chance of cancer. no amount is safe.

There are two types of fit testing, 1. quantitative and, 2. qualitative. For quantitative fit testing you’ll need a machine (ex. Portacount),  a respirator that will protect more than 50x the limits (>full face).  I will not cover this type of fit testing in this post, but it is very similar.

For qualitative fit testing you will need:

A medical clearance (not needed if you are wearing a paper dust mask) for each employee wearing a respirator.

Respirator w/P-100 filters (1/2 face respirator or more protective), aka HEPA filters, purple in color.

fit test kit -your choices are: saccharine, irritant smoke, Bitrex, or isoamyl acetate-bananas. Buy it online, or at your local safety supplier. Look at their instructions.

My preference is to use irritant smoke. The reasons are;

1.  if they cough, it means they smelled it.
2. it doesn’t require a containment to be built to perform the fit testing.

The employee must be clean shaven around where the mask touches the face.  I allow “short” goaties where the facial hair does not touch the mask. The fit test procedures are easy to follow and found inside the kit. There are 8-steps, do each one for about 1 minute each.

As you fill out each individual’s form, make sure you include:

• if the employee is clean shaven
• what type of respirator is being worn (size, brand, model)
• what type of filters are being worn
• what type of fit test kit you used

While you have the employee captive, you might as well give them some training. Here are some questions and/or points to note.

• did you train them on positive & negative fit checks?
• why are they wearing a respirator?
• what are the limitations of their respirator?
• how will they store the respirator?
• how will they sanitize it?
• will they share their respirator?

Finally, sign and date the form. It expires one year from this date. Simple? yes.  Easy to forget something? yes.

Living in the NW, stucco is not as prevalent, compared to other areas of the US, as a building material. I finally got the opportunity to perform air monitoring for silica during stucco crack repair. From what the contractor explained, only the top layer of stucco (1/8 inch) is removed. He claimed the top layer is mostly an acrylic. The employee was wearing a 1/2 face tight fitting respirator with P100 (HEPA) cartridges. In addition, engineering controls were used.  The contractor had a grinder with a shroud and vacuum to remove the dust. This would not be considered a worse-case sampling scenario. From conversations with the plasterer-employees onsite, grinding is usually “VERY dusty”.

Sampling performed only for the duration of the grinding (3 hours). Conclusion?: We did not find any detectable levels of silica or respirable dust.

Please don’t use this sampling as the only information on how to proceed for your project. However, here are my observations:

• If acrylic material is the top 1/4 inch, you may not impact silica (or have any airborne).
• Airborne dust was very well controlled by grinder with shroud & vacuum (see pic below).
• Assume you will have dust until you can observe (or prove) otherwise. Wear a respirator.
• Perception is huge. If there is a big dust cloud coming from your grinder—even if there’s no silica… the observers don’t know the difference, and, well,…you know the story.

 

I was asked to perform asbestos training…and, “…maybe talk a little on lead”. However, I knew the employees needed to hear something totally different.

The firm requesting the training was a large excavation company that does a lot of road work. The training was at their bi monthly company wide meeting . I was given one hour.

So, my idea: Give them a quick overview of asbestos and lead, and then talk to them about silica. I called the training, “IH Health Topics in Construction”. And, as suspected, the questions that were posed all dealt with either: 1. “in my home I have…” or 2. silica and how to protect themselves.

I have made it my personal aim to talk about silica to as many employees as I can. I throw it into any training (even if I have just 5 minutes). Chances are, these guys WILL have overexposure to silica.  The owner did not mind since I told him we were going to talk about a few different kinds of health issues in construction.

My suggestion: see if you can work Silica into your conversations and trainings.

If you use heavy equipment and need to move dirt, rocks or soil, look closely at the buckets. Many times they will be coated with a material called hardfacing. It is a durable (consumable) welding bead laid out in a pattern. This pattern (from what I am told) helps to extend the life of the bucket. Apparently the cost of putting this product on the buckets is well below the cost of replacing the bucket (or teeth, or whatever).

The hazard is really on during the application of hardfacing. See my earlier post here. Hardfacing contains stainless steel (approximately 25%?, but it varies). Heating the stainless steel releases chromium in it’s hexavalent form (Cr6).

If your buckets have this on their exterior, your employees are probably exposed to hexavalent chromium at some point in the year.

However, the pattern is an art & science. Look closely at the side of this bucket…I think I know where this welder got his inspiration.