Industrial Hygiene in Construction

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)

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.

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.

I’m easily impressed with welding and welders. Welding looks so simple, yet hard, dangerous and permanent.

When interviewing your welder, here are some questions to ask:

• What type of welding are you doing?
• What type of metal do you weld on? (mild steel, stainless, galvanized)
• Is there any coating on the metal?
• What type of flux is used?
• Where do you weld?, and then, “Where else?”
• Is there any ventilation in the area you weld?
• Are there any flammables in the area?
• Do you wear any PPE when welding? (ear plugs, respirator, leather)
• When do you use fall protection?
• Do you have & use welding shields?

What makes welding so difficult is the number of variables involved. The welding variables can change by the minute. Educate your employees on these dangers.

After the above questions, if the employee is agreeable, I ask some additional questions. These are the ones that provoke the best stories:

• What is the strangest things you’ve welded?
• Have you ever welding in a really small (confined) area?
• Have you ever welded with exotic metals? fluxes?
• What’s the worst thing you’ve welded on?
• Have you ever gotten sick from welding?

There are many, many more questions to be asked depending on the answers. The authority on this subject, Michael Harris, has written an excellent book on this subject, “Welding Health and Safety“(ISBN 978-1-931504-28-7). It is available from AIHA. It is VERY detailed, and money well spent if you do welding. I have taken his short course (all day) and I learned more than I ever thought possible, and I still can’t even weld!

Since you are reading this, you probably know the answer. Everyone. But, who is everyone? It should include your CEO/Company President/COO (or similar). If not, I guarantee you aren’t working as safely as possible.

The reason:  The person doing the work usually isn’t involved in the bidding & planning of the project.  It’s not always the President’s fault that the proper safety equipment wasn’t bought, or there are no available tie off points on the roof. (But, it might be their fault if they are willing to press forward without making changes.)

Here is one way to deal with these issues. Train the CEO (President/COO/Project Manager/Estimator) beforehand. Here’s how:

• Make the training for them. 
  • Don’t talk about safety harnesses, or the three different types of asbestos.
  • Go over big items (where are your claims? what are similar claims for your industry?)
• Emphasize the proper methods to control any hazard:
  • #1 engineering controls
  • #2 administrative controls
  • #3 PPE (in that order!)
• Get them to contact you during the bidding process (not after you’ve won it). Talk about what might be dangerous work & plan for it.
• Share a success story. Ask a superintendent to explain how they controlled a possible exposure.
  • Did they make the architect install in a tie-off point?
  • Did they ask the owner to change adhesive products to a less hazardous one?
  • Did they use an abatement contractor who performed the work well?
• Keep it simple & short. You don’t need a lot of time, but you do need them all on the same page.

When everyone in the company has the same interest in safety, it isn’t hard to explain.

Hair growth for your ears! This type of hair growth is different than the hairs which grow longer as you get older… 

The problem with most types of hearing aids, cochlear implants, and other types of enhancements is that they only amplify the body’s ability to hear. I talked about a type of pill we someday might be able to take that helps, here.

Research has found a way to regrow the hairs in your ear…well, at this point, only in mice. But, in theory, you could put these hair growth cells in the part of your ear where you have the most damage…and, well, it might help!

The summary article is here. The original article is here. And, to nerd-out, here is the research paper.

Controlling most of these types of exposures is really simple. If you know the job- and you know it will generate airborne silica = Pre Task Plan!

I wish Superintendents would enforce their project managers, or project engineers, to make a pre-task plan for every concrete/silica producing task. Then, (please don’t stop yet), review the plan once the project starts!

Below are two examples with different outcomes:

1. Cutting concrete block.

The pretask plan called for a garden hose with attachment(s) to wet the cutting area. Everything was perfect until the water was shut off. But, they improvised and found an electric water pump with bucket and recycled the water. It was a great outcome. What if the power went out? They could have used a Hudson sprayer.

2. Grinding plaster off a brick wall.

They built an enclosure and containment. They had a negative air machine with HEPA filters. They had a vacuum with HEPA filters, tyvek, 1/2 face respirator, eye protection, etc. But, as they worked the vacuum couldn’t keep up with the amount of dust generated by the 7 inch Bosch grinder. It was really dusty. They worked like this for days. No one onsite saw them because they were in containment. Unfortunately  the project is almost over and it could have been better. A simple shroud to the grinder, like this one (no endorcement) might have controlled the dust & silica. Sure, it might have been troublesome to find the exact one, and get a vacuum attachment, and have the extra weight, and ….

So, let’s talk to people about silica, talk about solutions, and then check to see if they’re effective.