Industrial Hygiene in Construction

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.

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.

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.

I was visiting a friend and in their neighborhood all of the curbs were cut for driveways (they were not poured for the cutouts). 

This might have saved some time for the carpenters forming & pouring the concrete. But it created additional work for the concrete cutters and the finishing of the driveways.

This lack of pre-planning created:

• additional time to cut the curb,
• dust (and silica, for sure),
• the use of additional water (hopefully) to control the dust,
• respirators (& cartridge filters),
• exposure to noise, dust, silica

I don’t know the circumstances why this occurred, but I wonder if the person planning the development thought of the exposures to other human beings?

ps. Sorry for my blogging absence. Have been on vacation! (for some of it)

Yep. Polychlorobiphenyls (PCB) are found in caulking. Typically buildings before 1979 have this caulk. (EPA Facts about PCB in Caulk) The only way to know is to test. BUT, wait!

Either:

• Assume you have it and renovate with caution. Or,
• Have the air tested for PCBs in the air.

Do not have a bulk sample taken. You should ask for an exposure assessment to be performed (air monitoring) by a qualified industrial hygienist. The reason is two-fold.

1. The potential for the hazard is airborne. In most instances, people aren’t getting exposure from any other method.
2. By measuring the air, you account for any other sources of PCBs (paint, ballasts, oils, ceiling tiles).

Most of this caulk is found in outdoor uses (high grade) in older buildings up to around 1980-ish. If an airborne exposure assessment finds levels below the acceptable rules & recommendations (depends on age & location), you may continue with your project. Of course, you would take appropriate precautions, like these recommendations from the EPA. They also have a very nice flow chart. Just like a choose-your-adventure book, make sure you don’t fall into the “Abatement” box!

Let me first say that I am still learning about this hazard and why it is so dangerous.

Polyurethane foam is used as an insulating material. More info on it’s uses here. The danger is when you spray it (think: expandable type), or apply it, or cut/remove it after it’s cured. The danger is in the off-gassing.

There are two main considerations:

• the process of applying the foam
  • spray type
  • quantity?,
  • ventilation?
• the type (manufacturer/brand/type) of foam
  • curing rate,
  • type of hazard, etc.

What we know is that there is a hazard. AND, this hazard may not effect everyone, OR, it may not effect you until some time has gone by. But, some of the chemicals in these types of products include:

• isocyanates (people can die, and get asthma), and it is a OSHA Emphasis Program, and OSHA page here
• amines
• VOCs (volatile organic chemicals)
• flame retardants (PBTs)
• Blowing agents (EPA link)

There is a huge potential for work related asthma when using these types of products. And, even contact with the skin can trigger an allergic response/asthma attack. If you have employees working around this type of product and have ANY respiratory symptoms (or asthma), please have them checked by an occupational medicine doctor.

Control of this hazard should include:

• PPE for employees (respiratory, eye, & skin protection)
• ventilation during application
• ventilation during off-gassing & curing (can be 72 hours)
• control plan for spills, cutting & demo
• control plan for employee/occupants with asthma

The EPA has a quick reference card here (hat tip to Tom), and more detail from the EPA on how to control the hazard here. The Spray Polyurethane Foam Alliance has free training here (haven’t checked it out though), and be mindful that anyone can be an instructor (good & bad).