Industrial Hygiene in Construction

This has to be one of the coolest types of cutting. Raw obliteration of metal.

As you know, hexavalent chromium (Cr6) is generated when the metal, chromium, is heated. Cutting this metal with a plasma torch is an easy way to heat it up quickly.  We performed air monitoring on one employee performing plasma cutting on #304 stainless. Luckily the employee was wearing a 1/2 face tight fitting respirator (and skin protection due to the body readily absorbing Cr6) and we found exposures at 36% of the exposure limits (they were within the acceptable limits). This employee was able to stand away from the cutting due to the machine he was using. He did not do this task all day and no engineering controls (ventilation) was used. 

****Caveat: Please do your own air sampling. Conditions and environment may not be similar to your environment, and they can change rapidly. One sampling event rarely indicates all conditions. We’re talking about people’s health!****Keep in mind welding safety! 

And a close up of the cutting machine without the motor & tracks:

I titled this post, “hazards of drywall”, but it encompassing most of the common hazards of plaster, mud, gypsum, wall-hangers, tapers, and acoustic employees.

1. Corrosive drywall.

   I have not dealt with this subject on a personal level. However, AIHA has a new guidance document titled, “Assessment and Remediation of Corrosive Drywall: An AIHA Guidance Document“, which is a clarification of an earlier white paper document from 2000, titled, “Corrosive Drywall“. The danger is from a specific type of drywall which was imported from China. After installation it is known to emit sulfide vapors, which corrode copper (electrical wires), and can give off a sulfur smell (HT to JeffH in Ohio).

2. Asbestos in mud/plaster.

   Be aware, some older buildings (pre 1980s) may have asbestos in the mud compound or plaster (not as common). This will be a concern if you are performing demo on these walls. Info here.

3. Silica (dust) in joint (mud) compound.

   Some types of silica I have found to have silica. This can be an issue when sanding. AND, if you install drywall like me…you do a lot of sanding. More information from an earlier post can be found here. NIOSH has some suggestions too.

4. Leaded sheetrock. If you are installing (or demo) leaded sheetrock, you NEED to protect yourself. Airborne levels of lead can approach the exposure limits, even during installation. More info here.
5. Lead in paint. If you’re tying into existing plaster/drywall and there’s paint, you need to know if there’s lead in it. Sanding on the paint is a good way to be exposed. More info here.
6. Ergonomics. Hanging the wallboard takes a toll on your body after 20 years (or less). Not to mention sanding. Washington OSHA (L&I) has a good demo.
7. Noise. Cutting steel studs, powder actuated tools (there’s lead exposure too, you know).
8. Skin hazards. Cutting, but also dermatitis from prolonged exposure to dust.
9. Eye hazards. Dust, carpentry, etc. Working overhead is an easy way to get falling items in your eyes.
10. Falls. Last on my list, but certainly not the least. Scaffolding, working from ladders, and using stilts, to name a few.

For better, or worse, the silica rule has been delayed, again. This delay is for an extension of the public comment period, which goes until December 12, 2013. Public hearings are set to begin on March 4, 2014.

Find OSHA here, with links to my previous post. A NPR story from February, 2013.

My views on this rule haven’t changed much: It’s still a mixed-bag. There are still overexposures to silica (see my pictures from the last 3 weeks). However, will the new rule change the behavior?

• Overexposures are still happening
• Silica deaths have decreased over the past (without the new rule)
• Will the small employers (the ones who typically offend the most) comply? Or just wait to be cited?

But, my overwhelming thought is this:

• Any new rule will generate “noise” for the subject of silica. And, that’s a good-thing.
• This will drive:
  • compliance
  • changes
  • innovation
  • discussions
  • awareness

I previously wrote about a worst-case scenario in which asbestos was not discovered till after it was disturbed.

Recently I heard a story of the opposite:

A general contractor hired a company to remove various pieces of asbestos. They had obtained an asbestos building survey, which clearly stated where the  asbestos was located. A boiler with surrounding insulation was identified as non-asbestos containing (asbestos-free). The employee was using a bobcat to demolish the boiler. As he started to tear into the insulation surrounding the boiler (disturb it), he paused. He checked the building survey again, and it had clearly stated it was “asbestos free” (actually 5 samples had been taken of the insulation around the boiler). Then, he did what most other people would not do: HE REFUSED to demo the insulation. He told the General Contractor and owner he thought it was asbestos containing and wanted it tested, AGAIN.

Guess what they found? Yep. Asbestos WAS contained inside the insulation around the boiler.

There was obviously some break-down in communication with the report, inspector, and possibly the lab.  However, this employee is to be commended and, really, the safety culture at this company should be congratulated. You never know where you will find asbestos.  The employee had enough guts to speak up for his safety (and for the others).

Measuring good-safety behavior is the type of thing we should reward. In the past (and still today) many safety-people measure losses ( ie. how many injuries). This is backwards thinking. We should be rewarding good behavior and encouraging people to speak up for safety.

For example; what do you say to this guy?

It’s sad to say, but many construction companies have not yet started a formal hearing conservation program. Their solution is to purchase the best earplugs, for the lowest cost, and give them away like candy.

As I’ve mentioned before: Sometimes OSHA’s rules are protective (meaning: you will be safe) and other times they are really not on par with the health research. Hearing loss and OSHA’s method of measuring noise are NOT protective to employee health (your hearing). For the best method of measuring noise, look to the recommended guidelines of the ACGIH. In order to get the exact parameters, you must purchase their Guide to Occupational Exposure Values (TLVs) booklet. It hasn’t changed (at least for noise) for a few years, but it is still the most up to date on health for your hearing. Here’s a summary of some differences:

• Exchange rate (how noise doubles and is averaged over time)
  • OSHA uses 5, ACGIH uses 3 >>which means noise doubles every 5, or 3 dB increase
  • this makes a BIG difference in your accumulated average noise level (TWA).
• Exposure Limit, or Criterion Level
  • OSHA says 90 dBA, ACGIH says 85 dBA
  • Doesn’t seem too different (-5), but remember noise is logarithmic and it’s measured different by OSHA & the ACGIH

NIOSH also has some guidelines, which are very similar to the ACGIH.

There are some strong benefits to having a hearing conservation program. Here are some examples and suggestions for bettering your own program.

• You can be recognized
• Win an award. 
• Have less (or even better: none) hearing loss claims
• What about just hearing soft noises? kids? hunting? sports? the TV?

If you have worked in construction for any period of time, you know how loud it can be, and how much exposure is out there. Don’t assume working in this industry that hearing loss will to happen to you. Do something about it. Here’s a presentation from CDC/NIOSH a few years back on how to start.

Hypothetically (and allegedly):

• You receive a project as a subcontractor.
• You are verbally told no asbestos or lead onsite. Only that’s not true.
• There is asbestos, and you, and multiple other subs, have disturbed it.
• The prime contractor says, “oops”. Has the materials tested, and then blames the owner for not letting them know.
• OSHA is called and citations are issued to the owner and GC for not testing and telling people.
• A year goes by and now both the owner and GC are being sued by 5 employees for $10,000,000 (yep $10 million, that’s the max BTW).
  • As a footnote: this incidentally is not a worker compensation case (yet) since they are not suing their employer (they are suing the GC and owner)

Even if the employees don’t win $10m, are you prepared for: the headache, loss of client-relationship, trust breaking? Here’s a similar hypothetical article about such a situation.

On the flip side, here are some positive things you can do:

• get a written copy of the building survey (lead & asbestos) ALWAYS. (you might also ask for cadmium, radon, other possible hazardous substances)
• Train your employees about asbestos prior to having to deal with it.
• Give employees the power to “stop work” if they are suspicious of possible asbestos containing material (PACM).
• When handing out a building survey to your subs, get their acknowledgment (in writing, of course)
• Fight your OSHA citations. Go to your informal conference. Present your evidence and, at the very least, beg for forgiveness.

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)

Industrial hygiene (aka occupational hygiene) focuses on occupational-related diseases due to many reasons.

Have you considered, at your home, maybe even as you sleep, you might be exposed to something hazardous? Below are seven possible hazards in your home (related to IH):

1. Radon. It comes from the ground and they say it causes cancer* (*some people question this toxicological data). You must perform a test to know if you have hazardous levels.
2. Formaldehyde. If you have a newer house you have 2 things going against you: 1. your house is tightly built (no air leaks and limited fresh air) and 2. more particle board (recycled wood) was used in construction. Also, many furniture contains multidensity fiber wood (MDF) which off gas formaldehyde. Again test for it to know if you have dangerous levels.
3. Lead. Is your house built prior to 1978? It probably has leaded paint. Any remodeling might distrupt it and you can expose your kids to lead.
4. Isocyantes. (HDI, TDI, MDI, and others) Can cause asthma & respiratory issues. If your house was insulated with spray foam (polyurethane type) it needs to off-gas for awhile before you move right in.
5. Asbestos. Causes cancer when airborne. If your house was built prior to 1980, you might have asbestos in your pipe insulation, popcorn ceiling, etc. Be sure and have it checked prior to remodeling.
6. Mold. Respiratory diseases.
7. Cleaning products. The symptoms can vary depending on the type of chemicals in the product. Use the recommended gloves, eye protection and respirator, if necessary, while cleaning with chemicals.

Do not be overly concerned about any one thing. Simply test and make any necessary adjustments. However, do keep in mind that most health recommendations for substances relate to normal working adults who go home to a non-hazardous place. There can be issues if you are either: not considered in the general population of healthy workers and, you go home to a place that isn’t free of additional hazards.