Industrial Hygiene in Construction

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

Let’s clarify: You are a working adult. You are feeling symptoms (of some sort). And, you think it’s from something your exposed to while at work (in construction). This could include, but will not, the flu-bug. Below is a list of the most common construction illnesses.

Most Common Construction Illnesses:

1. Upper respiratory
   • could be from silica, drywall, dust, asbestos, nuisance dust, chemicals (I won’t even try to list all of them)
2. Skin (dermal, dermatitis) damage –
   • From: concrete, abrasion, chemicals
3. Eyes
   • mostly from things that get into the eye.
4. Cumulative trauma (ergonomics) or inflammation
   • repetitive motion, over a day hurts, imagine this for years
5. Burn (heat or chemicals)
   • Usually around hot work like welding, but this can occur when using certian chemicals
6. Hearing loss
   • cumulative trama to the ears when exposure is above about 85 decibels for any extended period of time.
7. Poisoning– General or systemic
   • From: poison ivy, stinging needles, dog bites, bees, etc.

This list may vary depending on many things including what type of construction you are in; GC, heavy, civil, specialty, etc.  I put this list together to get a picture of where we see illnesses. However, as previously mentioned, and, everyone knows, the FOCUS FOUR is really where most injuries occur in construction.

We have seen the most prevention of illness due to one single device:

the back support.   ha. just kidding, of course.

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.

Yea, I know. Strange one, huh? In my time consulting, this is actually the second time I’ve come across this.

It is more commonly know as: Mace (R) or tear gas (not pepper spray though, that is Oleoresin Capsicum). Hopefully you haven’t actually experienced it’s exposure. It is worse (so I’m told) than pepper spray. More differences compared here.  All can be quantitatively measured by your favorite occupational hygienist.

Exposure in construction can come from incidental releases (incident response) or during clean up/ demolition of structures where this was used (think: police entry into a structure).

The OSHA exposure limit is 0.3 mg/m3. (NIOSH REL is the same, ACGIH TLV 0.35 mg/m3). They are all very low, actually.  Exposure can occur by inhalation, eyes, ingestion, and skin exposure.  NIOSH Pocket Guide is here.

Personal protection is a bit interesting. NIOSH recommends a full face respirator with P100 and organic vapor cartridges be used. The interesting part is that using this type of protection would allow exposure (based upon the protection factor) up to 15 mg/m3. Which, incidentally, is also the level as immediate danger to life and health (IDLH) = 15 mg/m3.

Some guides for dealing with this substance can be found here.

Chromium in it’s elevated valence state, called Chromium 6, or hexavalent chromium is a known carcinogen and sensitizer. From a toxicological point of view, it has a really interesting exposure to disease path.

I’ve mentioned it before, but recently NIOSH reduced their suggested limit from 1.0 µg/m³ to 0.2 µg/m³ (80% reduction for you math wiz’es).  They base this on eye & skin irritation, respiratory damage & lung cancer. Yikes.

OSHA has listed their exposure limits, along with other’s recommended limits here.

The take-away from this reduction is the serious nature of Chromium 6. If you are dealing with this hazard, you should take more than just a little precaution. Even if your prior air monitoring data is below the Action & Exposure Limit, continue  to document and verify your employees are well below the regulatory & recommended limits. As you know, hexavalent chromium is a skin hazard and can be absorbed easily into your body. I would also suggest performing wipe samples (area & skin) & decontamination in areas where there is work activity with hexavalent chromium.

For most construction companies, investigate these areas:

• welding (any stainless steel?) See this earllier post, also here.
  • And, OSHA has a new Fact sheet on welding & hexavalent chromium here.
  • Washington’s OSHA (L&I) has a great page on the hazards during welding here, including training videos. (so cool!)
• hardfacing on equipment. See earlier post.
• Bridge painting – (or painting with chromates) OSHA’s new safety bulletin is here.
• Electroplating – OSHA’s safety bulletin is here.
• Anytime you heat, or work with chromate painted surfaces.
• Portland cement when working with it wet and on your skin. NIOSH has some information here. hint: Try adding ferrous sulfate to lower the Cr6.

And, if you don’t work in construction, but live in Garfield, NJ, you might have to pull your toenails out to prove you aren’t exposed to hexavalent chromium.

You already knew it. There is a lot to do in industrial hygiene. At times this occupation feels like a safety middleman trying to keep people out of trouble. Occasionally I’m rewarded with really helping someone. In the United States, there is still a lot of occupational hygiene issues and concerns. Overseas, particularly in developing countries, there is even more.

It is hard to obtain accurate exposure data, or illness rates, from these underdeveloped countries. (How does a village of 1,000 people in Kenya report that they’ve had lead exposure to battery recycling?) How these exposures are brought to light is by either a massive death (# of people, quickly) or, someone with a camera able to actually photograph the pollution. As we know, what it looks like doesn’t necessarily correlate with hazardous levels of exposure. But, in some cases, it’s pretty obvious.

I ran across this photo story on pollution (The Guardian, UK). They estimate 125 million people are exposed to industrial pollutants (generic term, I know). This makes occupational related exposures a health risk as big as TB and Malaria! The article is based upon a report from the Blacksmith Institute which included this map of the worst pollution with associated disease.

How does this apply to construction? The worst offenders are lead (Pb) (and other metals), and asbestos.

What can you do? Here’s their recommendation, from the report (p50):

Developing countries need the support of the international community
to design and implement clean up efforts, improve pollution control technologies, and provide educational
trainings to industry workers and the surrounding community

Another NPR article about lead poisoning can be found here.

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.

An agricultural sprinkler and pipe fitting company would not be first on my list for hexavalent chromium exposures. However, they hired a great manager who happens to keep up on safety concerns. He identified the hazard before any work had started.

This company makes custom fittings and pipe for municipals and agricultural systems. The most durable pipes are made of stainless steel. An employee was performing TIG welding for elbows and joints for a new system. In the past I have found that TIG welding produces the least amount of airborne hexavalent chromium (Cr6), so I was not too worried about the airborne levels that might be measured. (keep in mind that there is still a dermal concern, more info here).

However, after interviewing the employee for awhile, he said that plasma cutting and stick welding also occur. Unfortunately air monitoring during TIG welding does not compare with plasma cutting or stick (arc) welding. Additional air monitoring during those activities will have to be performed.

Sometimes it is extremely hard to protect the hands of people in construction. A typical construction worker may need leather gloves all day…until the end of the shift when he uses the solvent to clean his tool. Previous cuts, scrapes and scabs make it easy for chemicals to enter. And, depending on the chemical, it may absorb through the skin, or at least, dry it out.

Below is a employee’s hand who had been working with acetone for years. He badly wanted his hands to feel better.

Here is a link to an excellent article by Donald Groce at EHS Today.