Industrial Hygiene in Construction

In construction there may be a time when employees need to weld on galvanized metal. This poses a unique problem since the zinc oxide fume can cause metal fume fever.  Should employees wear a respirator? Should mechanical ventilation be used? Should they drink milk? before? during and after welding? 

As with my answers to all welding types:  it depends.

However, I will make some generalizations. I have not seen a lot, or high airborne exposures (to zinc oxide) during galvanized steel welding. But, I typically recommend that welders are prepared and ready to wear a respirator if the need occurs. Welding is so variable, it is hard to make generalizations that cover all aspects.

Some questions that I ask before issuing respirators include:

• Does the welder have experience and training with this type of welding?
• How long will the welding occur?
• Is it spot welding? or for a duration of time?
• Is there mechanical ventilation in place, and can it be used for the entire project?
• Is there any portion of the welding that will be in a confined area with limited ventilation?
• Are there any coatings on the metal? Lubricants?

Once a respirator is decided to be issued, I only recommend a 1/2 face tight fitting respirator with HEPA filters. I know that N95 and other types of filtering dust masks do provide protection, but they, in my opinion, are not adequate if you really need them.

And, as far as drinking milk. If you feel sick after welding- drink it. It won’t hurt.

How much information should be contained in your written safety programs? There isn’t a right answer, but here are my suggestions and thoughts.

Have two “levels” of programs.

Corporate Safety Programs –

• This type should contain the general overview of the safety at the company. It should speak to the concern that the company has to the safety of the employees.  ie. “we don’t want you to get hurt, so…”
• No details. For example,  an Asbestos Policy statement – “As a company we anticipate that we may encounter asbestos onsite. We train our employees in identifying suspected asbestos containing material (ACM) and subcontract any work where we may disturb potential ACM. “
• Employees should be trained from the Corporate Safety Policies (initially, annually, or periodically thereafter).
• Establishing these programs should take a lot of thought, consideration, and buy-in from management and leadership.
• Do NOT make a policy that you do not plan on keeping. If you are going to occasionally do something which is a direct contradiction to your policy – don’t make it a policy. I know, simple in theory, but…

Site Specific Programs

• These types of programs should contain the details. Who, what, when, where, how.
• Only include the policies that you have at the jobsite- otherwise don’t have this policy on file in the trailer.
• Cut and paste the policies you need for this specific job – from your corporate program list.
• Another example, from the asbestos policy, “on XXX project we have identified asbestos in the blue and green 9×9″ floor tiles to contain 5%asbestos. ABC Abatement Company will abate and remove any asbestos found. If additional materials of this size, shape, color are found, please notify the superintendent immediately”.
• Perform tool-box talks from your site specific programs. These programs should have enough detail that your Project Engineer could read it to the employees and have enough information.

During mild steel welding I very rarely see respirators being worn. I believe this to be “standard practice” (the act of NOT wearing a respirator). However, is this a good idea?

The correct answer is:  It depends.

Explanation:

• I actually think during common mild steel welding, respirators should not usually be required. My experience in air monitoring has demonstrated that most “average” levels are well within occupational exposure levels (OELs).  While sampling under the hood (placing the filterpiece inside the welding hood), the flash hood protects from a lot of exposure. Most of the particulate that is seen-visually is iron.

Caveats:

• “average” welding changes everyday. What is average at one fabrication shop may be totally different from another. Each project may have different welding exposures. Welding inside a 36 inch tube is different than in an open field. You should roughly know what airborne levels you have at your site.
• If the welding contains metals other than what is in typical mild steel (and many times there are other stuff), the air levels can vary. Steel nowadays is so much recycled metal that there is a huge variability in the makeup of new product. Exotics (stainless steel, etc)  and known contaminants (leaded paint, coatings, oils, etc) should be treated very different.
• Long term exposures from metals might be a real health concern. There aren’t many metals in mild steel that you need to inhale.

Finally:

To wear respirators is a good decision. Conditions change and, in construction, this might be every hour. When the project needs to be completed quickly, most welders will not run to the store for a respirator. It is nice to be prepared.

My advice is to issue half-face tight fitting respirators with HEPA (high efficiency particulate air) filters. Train employees WHEN to use them and, if you have safety culture that permits it, trust them to use it when conditions warrant their use.

One of my pet-peeves is reporting industrial hygiene results with absolutely no explanation of what happened (or the conditions) on the day of the survey. The results will never be reproducible, verifiable, or really ever used again. If you are going to perform the exposure assessment, tell us what happened. We all know that an “average day” is rarely ever the average.

Sometimes you are not able to choose the time when you are able to perform air sampling or monitoring. But, that is a very important part of the overall picture of the exposure. When sampling I very frequently hear, “You should have been here yesterday”, or “Today is really slow”, or “Can you come back next week when we are doing XXX activity?”.

Those phrases and employee interviews are almost as critical as the air sampling results. They tell you what you DIDN’T see, or capture in your exposure monitoring.

At a minimum you should tell a story about:

• what engineering controls are in place
• what administrative controls are used
• what are the employees doing
• how often does this occur
• is this a worst-case scenario, or just average day
• what happens during set up and clean up
• what products are they using (MSDS)
• what PPE are they using

Leaded sheetrock is what the name says, sheetrock with a lead layer. It is used in hospital x-ray rooms and other health office clinics for containing / controlling the emitted x-rays while the machines are in use.

Plastering / Drywall companies who install this type of drywall need to follow the OSHA Construction Rules for lead work. I have heard of airborne exposures being at the exposure limits (50 ug/m3) during the installation due to the cutting and breaking of the drywall. My own personal monitoring has been below the Action Limit (30 ug/m3), but I have consistently found levels above the detection limit. This information should be taken as a caution to others.

For starters the employer will need to provide:

• half face negative pressure tight fitting respirators with HEPA cartridges
• protective clothing (like Tyvek (R))
• containment (for the dust generated)
• training (in lead and respirators)
• hand washing / changing areas
• HEPA vacuums for clean up
• possibly air monitoring (by a qualified industrial hygienist)
• possibly blood lead testing

The sheetrock should be contained during transport. Installation should be performed in a contained area with employees in respirators who are trained and competent. Clean-up should be done with HEPA vacuums. Air monitoring should be performed to assure that employees were adequately protected during their activities.

Working with this type of material is no excuse to cut corners (no pun intended). Protect your employees, the hospital, the patients, and others.

By definition, “if you work around, or near asbestos”.  Which leads to:

When do I work around it?

• Answer: Buildings build before 1985 (some say 1980) might have it.

How do I know if I’m working around it?

• Answer: Any structure build before 1985 must have an asbestos building survey performed and the contractor have a copy of it on hand. (and while the inspector is onsite they might as well check for lead (Pb)).

So what type of training do I need?

• Answer: It depends. Either Class III or Class IV Training is required by OSHA (see earlier post).

We subcontract any asbestos work, and typically it’s already abated before we arrive onsite. Do we still need training?

• Answer: Yes. OSHA does not define any training shorter (less involved) than Class IV (which is 2 hours). And, what I commonly see is that employers don’t train their employees, they find asbestos, disturb it and then get in trouble.

Any advice for how our company can avoid getting in these situations?

• Answer: Train your office staff before you actually train your hands-on employees. If your estimators, project managers, superintendents and vice presidents know what to look for before bidding a job, then everyone has time to prepare and get the proper surveys, documentation, assistance, and training.

I attended a great session at an Industrial Hygiene Expo and Conference. Nowadays anyone with internet can find these useful apps, but it sure was nice to just sit there and watch them explain what they liked/disliked about each smart phone application.

Here are my top “useful”picks (mostly from their list). I like the free ones…Disclaimer: I didn’t develop these, nor have I loaded them all, or attempted to use them. 

1. Chemical Compatibility Database – might be really handy, if you remember to use it before you mix those chemicals
2. Lightmeter – I can see this one being really useful on those dark construction sites
3. IH Dig – if you r one- you gotta have this game
4. Converter Plus – mg/m3 to ppm, etc.
5. Cargo Decoder – all those DOT placard trucks running down the road- now you  know to be scared of
6. Time Calculator – allows you to add time(s) easier
7. Sound Level Meter – yep. and it works. Well, probably not in court.
8. Velometer – I can’t really tell you how it works, or if it’s accurate, but it might help sometime
9. Floor Plans (on the fly) – if you need a scale or a floor plan from a picture on your phone
10. Translators – these are really handy if you’re not fluent

The big scare in commercial construction is a new Senate House Bill 596 which makes certain insulation with the polybrominated diphenyl ethers (PBDE) illegal to install if you’re in Oregon. I think this bill caught everyone off guard.

PBDEs are used in fireproofing as a flame-retardant. However, they are in LOTs of other things including; foam products, plastics, couches, etc.

The issue is that this chemical(s) is a bioaccumulator. And this description is telling. It accumulates in your body. Health studies are inconclusive, and forthcoming, but it could be linked to brain development, memory, learning, and lowering thyroid hormone levels.  Most all symptoms are long term, but as mentioned before, it accumulates.

For more information about PBDE you can start at the Agency for Toxic Substances & Disease Registry. The Oregon Health Authority is enforcing the rule. The Fact Sheet is here dated January 28, 2011.

I am cautious about saying if this is a real-public health issue, or just a passing scare. Honestly I don’t know. I haven’t seen a lot of information about the health effects from unbiased sources (please point me in if you have).  Regardless, this is in some brands of commercial insulation, and if you’re in Oregon, you should not install it.

I know, the title is wrong.  It should read:  “How to prevent hearing loss“.

Here’s the problem (IMO).  I think most people know how to prevent hearing loss- and in America we can all afford to buy ear plugs. I have also heard of hearing loss claims that are unfounded and totally unrelated to their current work activity.  Even just a one time loud event can cause permanent hearing loss.

Construction companies hand out ear plugs like candy and say, “wear them when it’s loud”. Then, these same construction workers go home buck-up a cord of wood, ride their motorcycle, shoot their gun, and then after dinner go to a rock concert.

So, to avoid a claim, here is my advice:

1. Measure the noise (by dosimetry) at your job site- and do it annually.
2. Start a “hearing conservation program” or, in the simplest words, have your employees’ hearing checked annually.
3. Educate (train) your employees in hearing conservation
4. Give them choices in hearing protection (different brands of plugs, muffs, etc.).
5. Manage their hearing- (see below)

If you notice a loss in their hearing- do something! To manage possible hearing loss, I suggest these additional steps:

1. Retest their hearing. On a Monday, before work.  (To avoid a possible temporary threshold shift)
2. Have another company test their hearing. (sometimes the equipment is out of calibration)
3. Remind your manager to enforce the employee’s use of ear plugs on the job site.
4. Offer to give them ear plugs to take home.
5. Have an Industrial Hygienist (IH) perform noise monitoring at the job site for the full shift (dosimetry).
6. Retest their hearing again a month or two later.
7. Have an audiologist review their audiogram & your noise sampling data and ask for an opinion.

As the saying goes, “if I had a penny for every time someone asked me…” Well, here are my most commonly (frequently) asked questions (FAQs) for dealing with asbestos and lead on a construction job-site.  These are my answers, so consult the appropriate governing body.

LEAD

• Do I need to comply with EPA’s new lead rule? How do I?

If you are working in a public area, or specifically, with kids under the age of 6, you MUST comply. Go to EPA’s website (www.epa.gov) and take an accredited training class and get your company approved for leaded paint activities.

• How do I know if I have leaded paint on my job-site?

If the building was built before 1978, a building survey (performed by an accredited inspector) should be taken. Rumor has it that leaded paint can be found in buildings up to 1985 or later. An accredited inspector can be found by calling the Construction Contractors Board, OSHA,  or the EPA/DEQ.

• Can I use a do-it-yourself lead testing kit?

Yes, but they can sometimes be misleading. They only test the surface paint -not the other layers below. In addition, these kits cannot determine the amount of lead, or the airborne levels of lead on your jobsite.

• I do have leaded paint on my construction project. Where can I find the current regulations on how to handle this situation?

OSHA (www.osha.gov), the Environmental Protection Agency (EPA) aka: Department of Environmental Quality (DEQ), the Construction Contractors Board (CCB), and sometimes Department of Human Services (DHS). Many of their rules overlap, but they all have unique rules that are designed for their particular jurisdiction.

• We had a building survey for lead hazards performed. Our accredited inspector had the paint tested and found that it was only 0.3% total lead. It is less than 1%, do we need to comply with the regulations since it is such a small amount?

Yes. Any amount of lead found in lead paint requires that comply with OSHA’s regulations. Depending on the project, you may also need to comply with the standards of other governing bodies (see above).

ASBESTOS

• How do I know if I have asbestos on my jobsite?

Buildings built before 1980 are required by DEQ to have a survey performed before any demolition or renovation.  The survey must be performed by an Asbestos Hazard Emergency Response Act (AHERA) accredited inspector.  They will take bulk samples of the material and determine the amount of asbestos present.

• The accredited laboratory reported the asbestos had less than 1% but more than 0.001%. Does this mean it has asbestos?

Yes, it has asbestos (less than 1%), but OSHA considers it to be non-asbestos containing. However, even at 1% asbestos, you would want to control the possible exposures. Work practice procedures, training, and PPE should be used.

• There is a small quantity (less than 10 linear feet) of asbestos on my jobsite. My employees may have to touch it. What type of training do they need?

There are four classes (or types) of asbestos work. Class I is the most hazardous and Class IV is the least hazardous. To answer your question-you need to compare your situation to the definition of Class III and Class IV asbestos work. Class III work is defined as, “repair and maintenance operations, where asbestos containing material, including thermal system insulation and surfacing asbestos containing material is likely to be disturbed”.  This type of training is 16 hours in length and must be done by a EPA/DEQ certified trainer. Class IV work is defined as, “maintenance and custodial activities during which employees contact but do not disturb asbestos containing materials and activities to clean up dust, waste and debris resulting from Class I, II and III activities”. This type of training is 2 hours in length and is the minimum. The particular type of training needed will depend on your situation.

• We obtained a building survey before starting our job-site. After we started demolition we found some “questionable building materials” that did not look like they had been tested in this report. What do I do?

Stop work. Call an accredited building inspector for the material you need to test and have the material tested. Then report the results to the owner, and others on the jobsite, within 24 hours.

• Our company policy is that we do not touch asbestos or lead. Do I need to write that down as “my company policy”?

Yes. Plus you should include what your employees should do if they run across a “questionable” material and whom they should contact.

• We subcontract all asbestos and lead work. Do I need to have my employees trained in lead and asbestos awareness?

Yes.  There is still a good chance that your employees will see or have to deal with these hazards on the jobsite.