Industrial Hygiene in Construction

I’ll admit it. My elevator pitch is not the best. I have a hard time trying to briefly describe what I do as an industrial hygienist. I usually answer the question with a recent example of a interesting project.

What would you hire an industrial hygienist for? Well, this article describes exactly when you would hire one. I bet the haz mat crew has at least one hygienist investigating this concern.

AIHA has published video on what IHs do and our job function (s). They did a much better job than I could have done, but, the video is NOT as exciting as real-life.

Background: A new client recently had an OSHA health inspection (industrial hygiene). He received citations stemming from overexposures(they found levels above the PELs) to airborne particulates.

The company wondered what to do next. Here were my suggestions:

• Fix the problem. You will need to comply and assure that your employees aren’t overexposed. Even if the inspection made you upset, use your energy to make the situation right. Focus your energy on removing the hazard, not complaining about how you were treated.
  • Engineer the problem out. Remove the hazard. If not,
  • Change your policies so no one is further overexposed. If you can’t fix it by the this, or the above method, then,
  • Provide personal protective equipment to affected employees.
• Request the full inspection package. – this will include the officer’s field notes, interview questions, observations and sampling methodology.
  • look through these documents carefully
  • keep them for your records
•  Informally appeal the citations.
  • at the appeal show them you have complied/changed
  • ask for a reduction in fines (it never hurts to ask)
  • ask to group the citations together – instead of citation 1 item 1a, 1b, item 2, etc. ask to narrow it down to just one
  • bring any additional information which supports your side and/or the changes you’ve made (including training docs, programs, policies, etc.)
• Resample the areas.
  • make significant changes to these areas. Then,
  • hire an industrial hygienist to perform additional sampling in these areas
  • ask them to document the changes you have made to reduce the exposures
  • review this with your safety committee & those affected

I’ve mentioned this before.

If you’re using these tools in construction please be careful.

Quick summary:

• the powder contains lead (Pb)
• you can be exposed to lead when it is airborne, AND if it gets on your hands & you eat it.
• lead is not healthy for kids
• Wash!

As you might be aware, there is a loudness of noise which your ears cannot be protected against. Your body’s system of preventing the sound waves from entering your ear are just too much for it to handle. As the noise (sound pressure) hits your inner ear the bones convert the physical energy (noise) into a chemical & neurological process so you are able to hear. Ear plugs and ear muffs are not sufficient enough to protect against the amount of noise exposure.

However! Sometime in the future we might have a pill to prevent this type of hearing loss.

Researchers have found that the chemicals, D-methionine, ebselen & N-acetylcysteine, battle chemical stress on your ears.  We are still a long way from being able to take a pill to avoid hearing loss. They must go through more testing and the FDA approvals.

But, isn’t that cool!?

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.

Yes. If you are in construction, I recommend it. Here’s why:

First, the rules. OSHA does NOT have a specific construction standard for hearing conservation. Why does this matter? Well, the current OSHA rules state that if you have 1 day (that’s only one day) of average noise level above an average of 85 decibels A-weighted (dBA), called the Action Limit, you are required to start a program. Obviously noise levels vary on construction jobsites. I’d guess that most projects have at least one day of levels above 85dBA’s.

And, these particular OSHA rules are terrible. Well, they are terrible if you care about your hearing. (see my earlier post). The rules are simply not protective enough. If you are exposed to noise for 8-hours a day at 90 dBA (the OSHA average exposure limit) you WILL have hearing loss (this is without hearing protection). Does that seem like a very protective rule?  I’ve heard talk about them changing it, but…I doubt it will ever happen.

Second, let’s consider cost vs. reward. To start a hearing conservation program you must measure your employees hearing , called audiometric testing (and do a few other things). It costs approximately $20/employee to do this per year. Compare this with the average claim (of hearing loss) cost of around $20,000. So, if you have 20 employees, and it costs you $400/year…it takes about 50 years to pay yourself back for NOT starting a program. ($20,000/400= 50 years)

Third, consider your employees. Having their hearing checked may seem like a hassle and a worthless exercise, but, some will appreciate it. I’ve found that employees like to know how they are hearing. It’s good if your employer cares how well you hear. It’s also a yearly reminder in hazard awareness to noise.

Because in construction, we know there’s noise!

If you’re dead-set on NOT having a program, you’ll need documented noise dosimetry for each employee, job task, and possible overexposure above 85 dBAs. It is possible  for a construction company to avoid having a program, but you have the burden to prove there isn’t noise. Call your favorite industrial hygienist for help.

The first question is, “why is this useful?“. Well, generally speaking, it is helpful to know if you are getting bare-minimum airflow, or if you are creating a wind tunnel on your project. Since many construction projects are not able to mobilize until the last minute, it is useful to make some rough guesstimates and calculate the airflow in the room. One squirrel-cage fan isn’t going to ventilate a warehouse, and 5 of them in a manhole will make welding impossible.  so…moving on.

Air changes per hour (ACH) is a function of the room size and the airflow into/out of the room. It is simply the number of times the volume of air is changed out over a one hour time period. One reason this calculation is so attractive to use is because there are recommended exchange rates for different environments. Some of them can be seen in the picture, the rest can be found here.

To calculate you must know:

• A = Volume of room in cubic feet (ft3)
• Q = Air flow of your fan (s) in cubic feet per minute (CFM)

Rather than reinvent the wheel Wiki has a good summary.

Caveat/Disclaimers. There are quite a few…so be careful.

• Mixing. The air never really mixes when you are exchanging air in this manner. It is dilution ventilation. So,
• Never use this method for any hazardous source, and
• Never use this for any carcinogens (asbestos, benzene, etc).
• Airflow into & out of the space is required, and is never ideal. Make sure there is space for the air to actually exchange.
• Make sure your fans work properly and do provide the manufacturers output.

Assume your general contractor reports that he has found a material (floor tile, popcorn ceiling, etc) with less than 1%. He wants you to remove it with the rest of the demolition because, as you know, “…if it’s less than 1%, it’s NOT considered asbestos containing!”.

Are you ok to remove it?

Yes, and no. There is more to consider. The “1% rule” (as it’s called) as it is called states that they only regulate asbestos containing materials if they contain more than 1% of asbestos. Here are a few other considerations:

1. OSHA definition. Don’t get stuck on the definition. If you have employees, you must still follow parts of the OSHA rules. At a minimum, you must train your employees, work practices, clean-up and disposal requirments. More details on training here.
2. How were the samples taken? If one bulk sample shows less than 1% asbestos, you still might have a problem. According to the EPA/AHERA sampling rules, some types of materials must have up to 7 samples taken. This rule is in place because, back in the day, asbestos was added to joint compound (or anything similar) and it could really vary in amount according to where you take the sample. In addition, OSHA does not allow for composite sampling (combining the layers).
3. Do you know that 0.99% asbestos is still bad for you? Asbestos is a carcinogen. The greater the exposure, the greater the risk of disease. Any exposure could be the one to cause the disease. If the material is friable and you are disturbing it, I would NOT recommend performing that activity. Hire an abatement contractor.
4. Finally.Let’s assume it’s non-friable, you are not going to disturb it (when removing it) and it’s less than 1%. What will you do if your neighbor next door decides to call OSHA/EPA? Do you have a written plan and procedure? Have your employees been trained on the hazard? How to remove it? How to dispose of it? …Sometimes bad publicity will get you in worse trouble than any monetary fine.

 

The new standard for material safety data sheets (MSDS) which incorporate the global harmonization system (GHS) rules are coming.

Federal OSHA has approved the rules, and in our state, Oregon, they have been proposed, with an adoption to take place in December 2013.

It’s time to panic!… No. Not really.

Most employers will have until December of 2013 to implement the rules. OSHA will be publishing additional (and hopefully, helpful) information on what to do. For most employers it will mean you need to do a few major things:

• Train your employees on the new rules
• Reclassify (rename) the hazards, mainly the flammable ones, which have changed the most.

If you really need help with this, or feel like you can’t wait until OSHA publishes more information, email or find me here and we can discuss.

For people who work with asphalt everyday, this may be a obvious statement: Silica is in asphalt.

There are two areas where this might be of concern:

1. During the mixing of the asphalt there is usually some ratio of rocks that are added to the product. The size of these rocks is where safety personnel should have concerns. If they are adding the smallest fraction of rock to the mix, you may have airborne exposures to silica. This size of rock is called P200 (or, using a 200 sieve screen to get anything less than 200 parts per inch). Usually this is seen during the transfer of rock from the loader or from the belt conveyor.
2. The other method of exposure to silica in asphalt is if you cut it. Rocks may contain silica. When asphalt is cut, you incidentally cut through various rocks (contained within the asphalt). Silica (and dust) is released during the cutting. Please use water when you are cutting asphalt. Direct the water at the blade.