Industrial Hygiene in Construction

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.

Many construction companies have a multi gas meter (s). Here is my word of caution: if you have one, know how to use it.

I bet if you’re reading this post, you do know how. However, do your employees?

This type of training is SO critical. Below are some common mistakes I’ve seen from construction companies using these types of equipment:

• Let someone else (a GC, or subcontractor) tell you if it’s ok to enter a confined space (or hazardous one).
  • = do you own monitoring, & use your own equipment!
• Use someone else’s multi gas meter.
  • =do NOT use someone’s meter unless you 1. know the machine and 2. are able to calibrate and see the documentation. Would you send your employees to work in an area you think there might be a deadly hazard? Treat the 4-gas meter like it is your only available tool.
• Not performing a precalibration and bump test before using the gas meter.
  • = ALWAYS perform a bump test (not just zero-out)
• Not knowing which sensors are inside the machine (and what they mean).
  • =train your employees on when/why it alarms. CO is not CO2.
• Blame the machine if it alarms
  • =the machine is alarming for a reason. You either screwed it up, or something is going on. Figure it out. I had a project where the handheld radios were interfering with the multi gas meter. It took us 2 days to figure this out. Luckily no one was so desperate to work they ignored the alarm. On another project, employees were telling me it was ok to work while the alarm was sounding off. Their response was that, “it always goes off for CO, but we aren’t worried”. Yikes! I was.
• Not knowing what the hazards are
  • =you must know what you are measuring for. If you have isocyanates inside the confined space, the multi gas meter is probably not going to give you adequate warning.- if any. Just like wearing the right type of filter cartridge on your respirator, know the hazard you are measuring.

People who work in industrial hygiene try NOT to admit fault. There are reasons;  legal implications, credibility, and of course, pride. Since this blog is about being transparent, I will confess I made a huge mistake. My mistake wasn’t disastrous, but it could have been.

Background:

Employees were using a hudson sprayer (pump style) to apply a liquid waterproofing material. Air monitoring was performed and found to be 50% of the OELs. However, given the environmental conditions, and different areas they would need to access, I recommended they wear 1/2 face respirators. The hazard was isopropyl alcohol and a 1/2 face respirator with organic vapor cartridges was sufficient, with goggles & protective clothing.

However. It wasn’t isopropyl alcohol….it was methyl alcohol (methanol). And, there is a HUGE difference. Organic vapor cartridges (filters) provide NO protection to methanol. I should have recommended supplied air respirators.

I feel terrible, and I apologized.

“Success does not consist in never making mistakes but in never making the same one a second time” – George Bernard Shaw

When clients ask me to assist in choosing a product, I try to recommend a product with the least dangerous chemicals in it. I understand this isn’t always possible. However, I try to emphasize the worst case health scenarios and leave it up to the company to decide how to proceed. There are reasons to use a hazardous (to your health) product.

However, here are some considerations when choosing a hazardous product:

• more hazard vs less cost
• more hazard vs less time actually using product
• more hazard vs cost of PPE
• more hazard vs what the spec says
• more hazard vs different hazard
• more hazard vs terrible health effect/potential
• more hazard vs perception by others on the project (by the GC/public/subcontractors, media, neighbors)

Another issue with chemicals is the names and nomenclature. There are so many different names, common names, chemical names, and sub names of products – it gets confusing.

One solution called, ChemHat.org, offers a unique way of considering other chemicals. Plug in the CAS# (Chemical Abstract Number) or the name, and it gives you some ideas.

Another alternative in choosing the best product is to ask.

• Ask your industrial hygienist if this product is safe and/or are there concerns?
• Ask the GC if this is the only product that can be used
• Ask the architect if there are alternatives that are equally effective
• Ask the manufacturer if they have comparable products without the XXX hazard

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.

When measuring by air sampling for a job task, or an employee’s personal exposure, how many samples should you take?

Sometimes it is easier to place one filter cassette (or media) on the employee for the duration of their day.  At the end of the shift, you collect your equipment, mail it to the lab, and they spit out a 8-hour time weighted average (8-hour TWA). This is simple and easy to understand.

However, if you have the time and resources, it is usually beneficial to obtain multiple samples throughout the day. Taking multiple samples allow you to:

• obtain peaks, lows, and anomalies.
• look at: set up & clean up activities (separate from daily tasks)
• measure multiple employees doing the same task (to better capture the job task)
• calculate your own time weighted average
• capture short term exposure levels (STELs), or excursion limits *
• choose appropriate PPE for short duration tasks
• determine if employees are “falsifying” the data (skewing the data high or low)
• reduce filter overloading (in some cases)

There are some reasons NOT to obtain multiple samples:

• collection limit constraints (sometimes the method of sampling does not allow for this type of multiple sampling)
• it can be costly
• it is very time consuming (and nearly impossible, if you have multiple pumps on multiple employees throughout the site)
• difficulty interpreting the data (the math, the inferences, etc)

If you are hiring an industrial hygienist to perform air monitoring, ask about multiple samples. It might be slightly more expensive, but the information and data might be worth the cost.

*ACGIH recommends that if the compound does not have a STEL, all airborne levels should not exceed 3x the 8-hour TWA as an excursion limit.

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.