I live in a moderate climate, but we had some 102 degree weather and it reminded me of how important it is to have a heat stress program and educate our workers.

Here are some tips and suggestions for keeping this hazard under control:

  • Mandatory rest/water breaks (time between work & break dependent on heat) in shade
  • Monitor/measure water consumption (& urine, if extreme)
  • Educate employees on symptoms and factors which might contribute (medications, were you drinking last night?= deydration)
  • Always work with a partner
  • Flexible work schedule (start early, leave when conditions get unbearable)
  • Increase ventilation
  • Consider the space (attics can be worse than conditions outside)
  • Provide easy access to emergency services
  • One of the coolest (pun intended) ways is a “smart” vest with a downloadable app – workers wear this safety vest and it will alert people when symptoms/conditions get bad (heart rate, temperature, etc). Developed in Australia by RMIT University in Melbourne.



I have given many safety training presentations (as you have, I’m sure). If you are lucky, the owner/president of the company will have a few words to say to the group.  I am sometimes amazed at what they say (or don’t say). Below are my tips and suggestions.

What to say:

  • Thank the employees for working and the contribution they make
  • We take your health & safety VERY seriously
  • Look out for your own safety, AND the safety of others
  • Thank your company safety director/coordinator/consultant
    • Support them and listen to them
    • Do what they ask you to do and pass it along to others
  • We want our employees to:
    • Go home to your friends & family
    • Enjoy your life – injury free. Now, and in the future.

What NOT to say:

  • We spend a lot of  money on safety
    • “Bob got his hand cut, and it cost us $1,200”
    • “We had to pay $1,200 in OSHA citations”
  • Don’t be stupid”  (thereby implying that accidents are generated from stupid people)
  • Our insurance costs are high because you are getting hurt.
  • I will give you ____ if you don’t get hurt (thereby encouraging under-reporting of injuries)


There are pieces of equipment used in construction which are VERY difficult to control their noise generation; open cabs of equipment, drilling machines, impact drivers/drills, and some mechanical devices are the first to come to mind.

Modifying equipment to control the noise is better than handing out ear plugs. But, before you modify the equipment, does your company have a “Buy Quiet” program? NIOSH & CPWR released some info graphics which can help start you down this road to considering noise levels when purchasing new equipment.

Before modifying equipment to control noise consider:

  • Does the manufacturer have a “factory approved” modification already available?
  • Are there any liability considerations if you make this change?
  • Have you discussed the modifications with:
    • The manufacturer? Engineers?
    • Operator?
    • Mechanics?
    • Scope of work?
  • How much noise reduction are you hoping to achieve?
    • remember noise is logarithmic, so a reduction of  1 dB is achieving a lot…
    • but not much practical difference in regards to operations
  • Measure noise before and after, both static and dynamic

noise engineering control

Sorry for the delay in writing. I have had some personal and professional projects taking a lot of my spare time. I have been preparing to present at a couple local conferences on Industrial Hygiene in Construction. It is a good exercise for me to ponder what I should say to these audiences. Here are some takeaways:


My latest guess (subject to change, by even tomorrow) is the Federal OSHA rule for silica will be enacted.

“Why”, you say? …well:

  • Current administration would love to push it through
  • Yes. It’s still an issue in the construction world. Have you driven by a construction site lately?
  • Federal OSHA is also talking about updating the PELs…and this one (silica) is an easy one
  • When?  No idea.

Falls in Construction:

This one is huge. In a bad way. If you look at what kills the most in construction, it’s falls (inclusive of scaffolding, ladders, fall protection, etc.) They cost a lot too. Not just in the number of people killed, but the claims & recovery cost are high. And, near misses in construction are VERY common. For example, just two weeks ago: An 18 year old roofer apprentice was working on a roof.  He stepped onto a piece of drywall and would have fallen to a concrete slab 25 feet below. Luckily someone had moved a piece of equipment directly under where he fell. He only fell four feet and had no injuries.

Hierarchy of Controls:

Is anyone working with these anymore? Just kidding, sort of. But, we can do a better job in construction of:

  1. Engineering Controls first. Can we eliminate this hazard? Has anyone asked to substitute this product for a safer one?
  2. Administrative Controls second. There are ways and methods which we do things in construction. These are usually passed down from journeyman to apprentice. Overall, this is awesome. For example, we need to rethink why we place the rebar on the ground? Can we use saw horses? Better material handling would save a lot of injuries.
  3. PPE third. And as a last resort.

Personal Protective Equipment:

Oh boy. There is a lot of room for improvement here. The wrong equipment, worn incorrectly, not used enough, and damaged. I don’t have the answer for this, except we should create and encourage the best safety culture possible.  I think this helps construction to take pride in their work, and their (and their friend’s) safety.

I am the current chairperson of the AIHA Consultant’s Special Interest Group (Consult SIG). We conducted a survey and asked the AIHA membership of industrial hygiene consultants what their needs are, and how, as a group, we could help them. A summary of the survey result findings was just published in the November, 2014 AIHA’s, The Synergist, titled, “What IH Consultants Want“.  

We didn’t make the front page. But hey!, we weren’t on the last page either (second page to back, ha).

Nov 2014 Synergist

I cannot publish it here due to copyright infringement, but email me if you want information on the results of the survey.

Instead of explaining how to calculate safe levels of chemical mixtures, this will be a reminder.

The American Conference of Governmental Industrial Hygienists (ACGIH) in their Threshold Limit Values (2014), has an excellent explanation of how to calculate a safe level of exposure. However, in summary, if separate chemicals have the same health effects (effect the body in the same way), they may do three things:

  1. Additivity – the sum of their exposure & health effect is A+B. More on this below.
  2. Synergy – the sum of their exposure is MORE than A+B. This is bad, and hard to calculate.
    • Similar in principle to smoking and asbestos. If you smoke and have asbestos exposure, you are worse than just the additive.
  3. Antagonism – the mixed chemicals cancel each other out. It usually never works this way.
    • But, as a terrible example, it would be like acid rain dissolving styrofoam. (I don’t think that’s true, BTW)

Back to Additive (Additivity):additive

If two chemicals (or more) in a mixture have similar health effects (central nervous system, or effect the kidneys, for example), then, until you know otherwise, you should assume they have additive effects. Have your favorite Industrial Hygienist use your air monitoring data to calculate the additive effects using the ACGIH Additive Mixture Formula.

This is useful for combining both full shift air monitoring data, short term, and ceiling exposures. Extreme caution should be used if the chemicals are carcinogenic (as low as reasonably achievable (ALARA) is best here), or if they are complex mixtures (diesel exhaust).

It’s a bit confusing, but worthy of reminding ourselves of chemical mixtures.

Do you smell dirty clothes in your indoor building? Do you suspect your heating ventilation and air conditioning system of causing the smells?

It might be what’s called, “Dirty sock syndrome”. Typically found in high humidity locations. A brief video overview can be found here (You Tube 2:03)

Lawrence Berkeley National Laboratory has good information on indoor air quality and how it affects people as they work. They also have some scientific information about how improving the indoor space (by ventilation, temperature, particles, etc) can create a better environment.

AIHA has a “Position Statement on Mold and Dampness in the Built Environment” (March, 2013).  It lays out the reasons to control moisture in a building, and some basic steps for remedy (spoiler: air sampling doesn’t usually help).

Bottom line: Check your coils before replacing your entire system. Replacing these might be cheaper. Or, sometimes they can be cleaned, but it is a strict protocol. One possible solution is here (I do not endorsement, or recommend this particular product/brand. Do your own research).

Unfortunately I have no problem finding an appropriate picture for this blog on Ebay. People are weird. Yuk.

dirty sock

I regret I don’t have the energy to post every question and situation on this site.

However, occasionally there are very unique questions. I won’t say how I answered them, but I will offer some considerations. Here’s are my two favorites from the recent past:

  1. My construction crew is working on a “special TI (tenant improvement)”, alongside an elephant who has Turberculosis (TB). What personal protective equipment (PPE) do my workers need to wear?
    • Is the TB active
    • Does TB transfer from people to animal, and/or vice versa
    • How much contact (distance, time, amount of touching, etc) will the workers have with animal?
    • Will you offer prophylactic shots? (to the employees, of course)
  1. We are going to be excavating the carcasses of dead sheep. What type of PPE will my excavator operators need to wear while performing these tasks?
    • How large of an area (2-3 football fields)
    • How long have the carcasses been in this area
    • Any additives to the soil/area
    • Will workers be in contact with dead animals?
    • Will workers need to enter the excavation?
    • Will you use a multigas meter (4 gas)?


I’d love to hear your best (or worst) questions.

I am ashamed I have not written on this topic yet. In fact, this issue is so close to me, it bewilders me why I never connected it to occupational exposures. It’s even a carcinogen, and I try to get as much of it as I can when it is around.

To summarize my personal examples:

  • My dad has skin cancer on his ears and annually has these removed.
  • My next door neighbor died in 2009 from skin cancer (metastasized). He was a county construction worker for 35+ years and was in the sun, with his shirt off. A LOT.

More recently:

There are some chemicals and foods, when taken/exposed, actually make you more sensitive to the suns UV exposure (aka: photosentisizer). A list can be found here. Some of them are:

  • foods: carrots, dill, clover, eggs
  • medicine: antibiotics, diuretics, high blood pressure
  • chemicals: coal tar (creosote), benzene, xylene
  • cosmetics

And, if you haven’t noticed, construction workers get a lot of sun exposure, especially in the summer. Don’t forget, welders can have high exposures, and our heavy highway (road paving) crews are exposed to coal tar pitch. We talk about heat stress, but we should talk about the long term effects of skin damage.

There are no specific OSHA regulations on UV exposure. However, there are some guidelines from the ACGIH. There might be an instance where we can work within our “hierarchy of controls” and and eliminate the exposure to the employee. However, with this hazard, rather than working on eliminating the hazard, I would recommend we provide PPE.

Do you provide sunscreen to your employees?

This topic is not industrial hygiene specific. However, it is a construction safety/cost issue. A lot of contractors do a poor  job at modified duty (light duty) for injured employees. There are a few reasons for this:

  • temporary worker (disposable employee)
  • no “light duty” for the hard work needing done
  • the superintendent doesn’t want them back
    • doesn’t like him
    • can find someone else to do job
    • job is over

One of the best methods to reduce your return to work costs (aka workers compensation costs) is to return employees back to (some kind of) work as soon as possible. Keeping these injured employees on the project where the superintendent was responsible not only impact’s their projects bottom line, it reminds them of the injured employee.

Here is a list of some light duty jobs from Safety Awakenings.

Also, psychologically, how do you treat your injured employees? I have a brother, when younger, who would cry over a little tiny scrape. However, when he was actually hurt, he would firm-up, not shed a tear, and act as tough as possible. Employees are no different. Their reaction really varies, and your response might also need to change. There is probably not a one-size fits-all approach, but being professional is a good start.

Do you:

  • Shame them (make fun of them because of their injury?)
  • Encourage their injury (baby those who get hurt?)
  • Highlight it (bring it up in meetings?)
  • Discourage the behavior? or the act of unsafe behavior?

As you know, sometimes it’s hard to find light duty in construction.mixing1

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