Industrial Hygiene in Construction

Honestly, I did not think lead exposure to adults (and even kids in small amounts) was an issue. Mainly because:

• OSHA has good (protective) rules on lead in construction (updated in 1993) and they mimic the ACGIH TLVs.
• We all have lead in our blood. (…and I seem to be doing fine)
• We are doing better as a society. For example: no more* leaded gasoline.

But, one technical session last year at a conference changed my mind. We have a long ways to go.

The point: low levels of lead may have significant health consequences. And, if you have lead (Pb) in your body–it is from a source.

If I haven’t convinced you, the CDC is also considering ANOTHER reduction in childhood blood lead levels. In 2012 they reduced the advisory blood lead levels (in children) to 5 ug/dl. Later this month (Jan 17, 2017) they are meeting to consider reducing this level to 3.5 ug/dl! Whether of not they reduce it, the fact they are considering it should further our attention.

And, if you think this just applies to industries with heavy lead, think again. It has A LOT to do with construction.

“Construction Program researchers and the New Jersey Department of Health and Senior Services (DHSS) conducted a surveillance study in 1993 and 1994 involving the voluntary participation of 46 construction workers’ families. BLL (blood lead level) testing of young children indicated that the workers’ children, particularly those under age six, were at greater risk of having elevated BLLs (≥ 10 µg/dL) than children in the general population”

We (you) must pinpoint the source of your lead exposure. And, it may not be obvious. Since lead exposure can occur from airborne levels and by ingestion, the sources of lead exposure can vary widely.

For example, in Flint, Michigan they changed water sources to a more natural one. But, *spoiler alert*, the water had more salt – which was corrosive – which leached higher levels of lead from the pipes. Other sources can include: kids toys, jewelry, fishing weights, battery recycling, glass manufacturing, etc. (the picture of the above light pole looks like galvanized metal, but actually contained 45% leaded paint!)

What to do…

• Train and make people aware of the issue (free video that we produced! 1:31)
• Blame someone. Just kidding. Find the source of your lead exposure.
• Before starting a project, know where the lead paint is, and the activities you plan on performing.
• Get your blood tested for lead levels
• Wear the proper PPE and ESPECIALLY have good hygiene
• Perform air monitoring (and probably wipe sampling) to verify lead is not escaping from project.

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).

I don’t hate all N95 respirators (paper dust masks rated by NIOSH), but they are used wrong very often in construction. And, if you agree, and need another reason to hate them,… guess what??

Now there are FAKE ones! Yes, people have actually copied the crappy dust masks and made even crappier ones.

The fake ones are easy to tell…if you can read the misspelling of NIOSH.  (NIOSH notice here)

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 ARTBA, NAM, 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.

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
  • N95, aka paper dust maks is ok** (but, I’ve got a strong opinion of these)
  • 1/2 face tight fitting respirator with P100 (HEPA) filter is best

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

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:

Silica:

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.

The latest push from NIOSH is ridiculous, in a bad way. It’s titled, “Recognizing N95 Day” on September 5. I’ve written about these types of respirators before.

Let’s start with:

• NIOSH estimates 20 million workers exposed to airborne health risks
• N95 (s) are the most commonly used respirator
• NIOSH certifies all respirators. And, OSHA requires all respirators to be certified by NIOSH
• All certified respirators must have an “assigned protection factor”, which is a level of protection they are able to achieve
• N95 respirators are certified to provide a protection factor of “up to” 5 times the exposure limit

For the record, I am not disputing how NIOSH certifies respirators, or if these respirators can achieve a protection factor of 5 (5x the exposure limit). I will also add that in the healthcare setting (hospitals) these might have a useful role.

Here’s the problem:

• If you need a respirator, you would NOT choose a N95. They are terrible fitting.
  • To put it another way: if you had to work in an environment which had a dangerous airborne hazard, would you CHOOSE this respirator?
  • Or another way: “There is a chance this N95 respirator might protect you, wear this just in case”. (?)
• If you have fit tested these types, you know they are hard to fit, and at best, mediocre in their protection. At times it is hard to fit test a tight fitting 1/2 face respirator on someone who is clean shaven.
• N95 respirators are handed out (like candy) at construction sites for any task which “may be hazardous”.
• Let’s be honest:
  • these are “comfort” masks. AKA:  peace of mind, not for protection.
  • these are cheap. That is why most employers buy them.
• And, let’s mention:
  • exposure levels can vary (have you measured the worst case scenario?)
  • change out schedule? Do your workers wear the same respirators every day? Do they change them when they start getting hard to breathe?
  • facial hair (no one who is on a jobsite has this, right?)
  • there are knock-off N95 respirators which actually aren’t certified (they’re fake)

In this instance I wish NIOSH would spend money on training people to use the correct type of respirator. Or, how to adequately measure the hazards found at various sites.

As a quick review. If you need to wear a respirator, here are the proper steps.

It is officially summer and construction road crews & roofing is in full swing. Some projects require the use and application of coal tar pitch. Not only is it stinky, it is is hazardous.

Here’s some info:

• Uses
  • Roofing
  • Asphalt seal coating
  • Pharmaceutical treatment for psoriasis (scalp/skin condition)
  • Graphite industry (in the production of graphite)
• General
  • Coal tar pitch is actually a make-up of a bunch of different substances (maybe even 10,000 of them)
  • Contains lots of polycyclic aromatic hydrocarbons (PAHs) and other chemicals including: benzene, pyrene, benzo(a)pyrene, phenanthrene, anthracene
• Exposure
  • can be exposed by inhalation, ingestion (is this likely?), or exposure to skin, eyes
  • considered a carcinogen if the product contains more than 5% of coal tar
  • cancers include: skin, scrotal, lungs, bladder, kidney & digestive
  • increases your sensitivity to sunlight (easier to sunburn)
• Safety
  • Pick a sealant/coating that does not contain coal tar. A list of some can be found here.
  • Avoid inhalation & skin/eye contact
  • Train your employees. A sample safety SDS (MSDS) can be found here.
  • Wear the correct PPE.
  • Air sample to determine exposures. OSHA has a method (58).
• Resources
  • OSHA Coal Tar Pitch Volatiles
  • CDC Coal Tar Pitch Volatiles

This has to be one of the coolest types of cutting. Raw obliteration of metal.

As you know, hexavalent chromium (Cr6) is generated when the metal, chromium, is heated. Cutting this metal with a plasma torch is an easy way to heat it up quickly.  We performed air monitoring on one employee performing plasma cutting on #304 stainless. Luckily the employee was wearing a 1/2 face tight fitting respirator (and skin protection due to the body readily absorbing Cr6) and we found exposures at 36% of the exposure limits (they were within the acceptable limits). This employee was able to stand away from the cutting due to the machine he was using. He did not do this task all day and no engineering controls (ventilation) was used. 

****Caveat: Please do your own air sampling. Conditions and environment may not be similar to your environment, and they can change rapidly. One sampling event rarely indicates all conditions. We’re talking about people’s health!****Keep in mind welding safety! 

And a close up of the cutting machine without the motor & tracks:

I titled this post, “hazards of drywall”, but it encompassing most of the common hazards of plaster, mud, gypsum, wall-hangers, tapers, and acoustic employees.

1. Corrosive drywall.

   I have not dealt with this subject on a personal level. However, AIHA has a new guidance document titled, “Assessment and Remediation of Corrosive Drywall: An AIHA Guidance Document“, which is a clarification of an earlier white paper document from 2000, titled, “Corrosive Drywall“. The danger is from a specific type of drywall which was imported from China. After installation it is known to emit sulfide vapors, which corrode copper (electrical wires), and can give off a sulfur smell (HT to JeffH in Ohio).

2. Asbestos in mud/plaster.

   Be aware, some older buildings (pre 1980s) may have asbestos in the mud compound or plaster (not as common). This will be a concern if you are performing demo on these walls. Info here.

3. Silica (dust) in joint (mud) compound.

   Some types of silica I have found to have silica. This can be an issue when sanding. AND, if you install drywall like me…you do a lot of sanding. More information from an earlier post can be found here. NIOSH has some suggestions too.

4. Leaded sheetrock. If you are installing (or demo) leaded sheetrock, you NEED to protect yourself. Airborne levels of lead can approach the exposure limits, even during installation. More info here.
5. Lead in paint. If you’re tying into existing plaster/drywall and there’s paint, you need to know if there’s lead in it. Sanding on the paint is a good way to be exposed. More info here.
6. Ergonomics. Hanging the wallboard takes a toll on your body after 20 years (or less). Not to mention sanding. Washington OSHA (L&I) has a good demo.
7. Noise. Cutting steel studs, powder actuated tools (there’s lead exposure too, you know).
8. Skin hazards. Cutting, but also dermatitis from prolonged exposure to dust.
9. Eye hazards. Dust, carpentry, etc. Working overhead is an easy way to get falling items in your eyes.
10. Falls. Last on my list, but certainly not the least. Scaffolding, working from ladders, and using stilts, to name a few.