Industrial Hygiene in Construction

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).

There are only a few instances when you are not required to perform fit testing. The main reason not to perform fit testing is if the employees are wearing a respirator voluntary. (meaning: it’s not required)

So, how do you know if it’s required? It’s required when:

• You have overexposures to a substance (it’s required by OSHA to wear a respirator- so make sure you know, perform air monitoring), or
• If everyone is wearing a respirator during this task (it’s probably also required, just not formally- ie. spray finishing, or my favorite sanding drywall dust) or,
• If your company policy requires them to be worn (management says: it’s required to wearing a respirator during this task).

So, if you choose voluntary to wear a respirator and there is NOT a policy, or law, that says you HAVE to wear one then, you don’t need fit testing. (but you do need a few other things, Appendix D, etc.)

There is only one other exception:

• loose fitting hooded /helmet atmosphere supply respirators (when used in areas not immediately dangerous to life and health (IDLH))

Some employers choose to use these types of respirators because:

• the employee wears a beard
• it is convenient to use
• offers eye/face/neck protection
• it offers a greater protection factor
• it’s easier to don/doff (take on/off)

These guidelines for fit testing are different than medial testing before wearing a respirator, as spoken about 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.

AIHA has released (2013) a white paper for guidelines on skills & competencies in silica specific to construction. It is a great outline for training your employees.

Some interesting points:

• Respiratory protection, and their respective assigned protection factor is mentioned. (Are you wearing the right respirator?)
• There is no mention of air sampling. Thank you. You do not need air sampling every-time, we already know it’s hazardous.
• They emphasize control measures for silica.

Another recent publication from IRSST in Canada explains the effectiveness of controls with regard to specific tools and where exposures are found in the industry. It has a lot of information, but if you are looking for the best method to control dust with a certain tool, it would be worthwhile to read the 108 page document.

The best resource for silica is silica-safe.org. You can create a plan for controlling it here. They have a database of tools & controls. Very handy. Someday soon we may see 3D printers able to make these dust controls and adapters for us at a moments notice. Until then, pre plan your task.

It’s always fun to hear about new/different situations especially when the contractor handles it properly.

During the start of a demolition on a 1989 structure, the first swing of the hammer produced a pile of vermiculite sand.

After some discussion on “what in the world is this doing inside a wall cavity“. The contractor stopped work, had an asbestos test performed and quarantined the area. The bulk sampling for asbestos came back with the report of “asbestos containing, but less than 1%“. Well, as you know (and as I have mentioned earlier) it may not be safe to treat this product like every other demolition project. In this case, the asbestos was very friable and by opening the wall cavity, it had definitely been disturbed.  The contractor quickly set up some procedures. Here they are:

• Stop work in area. Quarantine area and place warning on doors.
• Train employees & subcontractors onsite to hazard (asbestos).
• Abatement contractor will remove wall & vermiculite
• Abatement contractor will treat the material as if it is asbestos containing
• Once the area is abated. An aggressive clearance test will be performed to assure no airborne levels of asbestos are present.

But why in the world was it in there in the first place? The best guess is it was added as a sound proofing / noise dampening for a air conditioning unit (actually a liebert unit) located on the adjacent wall. No other wall cavities contained the material.

From what I have seen, there are not a large amount of formaldehyde exposures in construction. However, there is A LOT of formaldehyde used in construction materials. Formaldehyde can be dangerous at levels undetectable by your nose. And, the symptoms of exposure are nondescript (irritant & tingling of eyes, nose, respiratory tract).

Here are some products that may contain trace (or more) amounts of formaldehyde:

• resins in plywood, MDF, CDX, particle board/fiber board
• garage doors
• drywall
• roofing
• glues / mastics
• paint/coatings
• carpets
• insulation (spray in and batting)

I believe the reason we do not see high exposures is due to the limited duration of exposure, and the open-aired nature during the construction. Some exceptions are warehouses with large storage areas of particle board/MDF. (I have found exposures in these areas)

The OSHA exposure limit for formaldehyde is 0.75 ppm (action limit of 0.5 ppm, and short term limit of 2 ppm). However, this may not be low enough, based upon other standards (ACGIH says 0.3 ppm, NIOSH 0.1 ppm)

Another major issue with this hazard in construction is once the space is occupied.

• Once construction is done, the space may be sealed up, heated, and additional curing can occur.
• This may release more formaldehyde, and also NOT allow as much to escape (by dilution ventilation).
• Compounding this issue are the type of occupants in the building. Are there children, non-working adults, immunocompromised individuals, sick, or elderly occupying this space? The OSHA standards are NOT protective for these types of people.

I do not forsee this type of sign being posted immediately after new construction.

On the plus side, someone has discovered that plants may help reduce formaldehyde & VOC levels in homes. Horticulture Science Kwang Jim Kim, et.al

Reviewing a material safety data sheet (MSDS), or soon to be called a SDS (safety data sheet), can be a useful skill. Most times the product is straightforward and gives you what you need. However, there are somethings to watch for and areas to focus to make your reviewing skills better.

To start,  make sure you have the right SDS. Match the product with the form. If is is not exactly right, find the right one. It must list the model/product name & manufacturer.

Below are some suggestions:

• What is the date of the SDS?
  • is it the most recent?
  • when was it last updated?
• Look at section 2/3 (Hazardous components) VERY carefully.
  • google the CAS# and find the name (they sometimes hide the true-name)
  • look at the % of each component
  • what is the listed exposure limit? Is it correct? What about other recommended limits?
  • remember the hazard is only listed in this area if it is greater than 1% of the total
• Look through each section mindful of how you will be using the product.
  • for example: if you are going to be burning the product, usually the SDS will not address these types of concerns/exposures
  • what are the required PPE during “regular use”
  • what happens if you use this product in a confined area?
  • does the manufacturer recommend air monitoring? when?
• Familiarize yourself with the emergency procedures
  • what if it spills?
  • disposal?
  • what can cause exposure? inhalation? skin?
• Look at the other sections with a inquisitive eye
  • do they list other chemicals, which are NOT included in the product section? why?
  • do they mention Proposition 65?
• Finally,
  • post/make available a copy wherever it’s needed
  • make sure you know the product

It is a mixed-bag when it comes to the quality of SDS from a manufacturer. Some of them will work with you, others are a total-pain. Remember it is YOUR RIGHT to know about the products you use. If you don’t feel comfortable with the information they’ve given you, call them. OR, go find another product.

NIOSH has just recommended a new exposure limit (REL) for hexavalent chromium. The new limit is 0.2 ug/m3 as an 8-hour TWA. If you remember, the OSHA PEL is 2.5 ug/m3 (8-hour TWA). SO, if you’re good at math, you can see this is A LOT lower.

The reasoning for this level is they have found a lung cancer risk (get this) EVEN AT 0.2 ug/m3. They recommend bringing airborne levels below this limit for lung exposures.

As I’ve described before, exposures are not limited to just inhalation. Dermal contact is a big concern.

If you have any hexavalent chromium at your facility, or stainless steel (welding, welding2, hardfacing, etc.) you need to do more than just air sampling. You need a comprehensive program including wipe samples, medical monitoring, etc. This may not be a specific OSHA rule for your facility.  However, these exposures are something you must manage.

You may have seen a product label which states that, “this product is known to cause cancer”…if used in California. (ha)

Proposition 65 is essentially a labeling rule. in 1986, California made a rule mandating anyone selling to California to label the product… if it had a serious health risk. This rule was above and beyond the OSHA reporting limit of 1%, like on a MSDS (henceforth called SDS, BTW).

The rule is actually good. It makes manufacturers tell you if there is anything hazardous in their product, or if they used anything hazardous when they made the product. (Side: If you haven’t heard, some manufacturers like to hide their ingredients, some say for proprietary reasons. Here’s an example)

More information about the rules is here. There is controversy over it’s usefulness (see here), but in this day in age, I believe you should be made aware of the information.

What usually happens is you find a SDS with no information about the product. Then, as you investigate, you find a “Proposition 65 warning”, indicating something about the product which, “may cause cancer”. So you ask, why does this happen? (more FAQ here) Well, the manufacturer used, or contains, something in their product that is hazardous. It can be a nice trail leading to chemicals which to sample for, or investigate.