Industrial Hygiene in Construction

For 100% selfish reasons, I debated about sharing this link.

Do you have an awesome idea for noise controls that uses technology?  NIOSH would like to hear about it. They make no promises, other than they will keep it a secret. But, this may be an opportunity to make your idea come to fruition.

I think the key to this “noise challenge“is to combine new technology for use in education, limiting exposure, or controlling exposures. Personally, I think construction has a lot of room for improvement. Unfortunately there is no money to the winner, but I think this may be a good thing, so as it promotes and attracts the people who want to do it for the right reasons. Here are some of my inferior ideas:

• make a low cost audiometric exam workers could do pre/post work to measure temporary hearing loss
• ask Google and Apple to install the sound level meter app in everyone’s phone. Then based on Big Data create “noise maps” so people will know how loud it is wherever they are going
• crease a device which produces acoustical waves which can be calibrated and set for stationary equipment. Once calibrated, it produces acoustical waves in the opposite direction – thereby cancelling the noise. (yea, I know, far fetched)

A new idea, SmartSite, which may spark some interest is a wireless health & safety monitoring system for construction sites similar to the residential “Nest” systems. They have a monitoring system set up on a tripod with a laser particle counter and noise level meter. The information is able to measured in real-time.

So working people, be challenged! Submit your idea by September 30, 2016. Email me if you do, and I will accept your challenge, and throw mine in the hat with you.

Do you smell dirty clothes in your indoor building? Do you suspect your heating ventilation and air conditioning system of causing the smells?

It might be what’s called, “Dirty sock syndrome”. Typically found in high humidity locations. A brief video overview can be found here (You Tube 2:03)

Lawrence Berkeley National Laboratory has good information on indoor air quality and how it affects people as they work. They also have some scientific information about how improving the indoor space (by ventilation, temperature, particles, etc) can create a better environment.

AIHA has a “Position Statement on Mold and Dampness in the Built Environment” (March, 2013).  It lays out the reasons to control moisture in a building, and some basic steps for remedy (spoiler: air sampling doesn’t usually help).

Bottom line: Check your coils before replacing your entire system. Replacing these might be cheaper. Or, sometimes they can be cleaned, but it is a strict protocol. One possible solution is here (I do not endorsement, or recommend this particular product/brand. Do your own research).

Unfortunately I have no problem finding an appropriate picture for this blog on Ebay. People are weird. Yuk.

I regret I don’t have the energy to post every question and situation on this site.

However, occasionally there are very unique questions. I won’t say how I answered them, but I will offer some considerations. Here’s are my two favorites from the recent past:

1. My construction crew is working on a “special TI (tenant improvement)”, alongside an elephant who has Turberculosis (TB). What personal protective equipment (PPE) do my workers need to wear?
   • Is the TB active
   • Does TB transfer from people to animal, and/or vice versa
   • How much contact (distance, time, amount of touching, etc) will the workers have with animal?
   • Will you offer prophylactic shots? (to the employees, of course)

1. We are going to be excavating the carcasses of dead sheep. What type of PPE will my excavator operators need to wear while performing these tasks?
   • How large of an area (2-3 football fields)
   • How long have the carcasses been in this area
   • Any additives to the soil/area
   • Will workers be in contact with dead animals?
   • Will workers need to enter the excavation?
   • Will you use a multigas meter (4 gas)?

I’d love to hear your best (or worst) questions.

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.

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).

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

…..: Red paint.

The point for the day is to remember that your sense of smell can be very good, or very misinformed depending on what you’re smelling (and who you are).

Sulfur (sulfur dioxide) can be smelled when it’s as low as 0.009 parts per million (ppm). The exposure limits are at 5 ppm. There are many chemicals that work just the opposite.

Before you make an assumption, figure out what you are smelling.