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.

If you live in the United States, you have less than one month to train your employees on the new Hazard Communication standard (1910.1200(h) & 1926.59), which should include information about the new types of Safety Data Sheets (formerly known as MSDS) and the adaptation with the Global Harmonization System (GHS). December 1, 2013 is the enforcement start date for OSHA. Don’t make this complicated, it is straightforward. Here’s what you should do:

  • Train employees in hazard communication (simply: so they know the hazards they are working with)beer
  • Document your training (in case of an OSHA inspection)
  • Show them a sample Safety Data Sheet (SDS), compared with the old MSDS
  • Explain that the new SDS will not be available immediately, but will roll-out over a few years (or more)

*Please note the “Beer” hazard warning on the right is not GHS compliant. 

For Help:

So, while standing in the California jet-way waiting to board my plane, I noticed this sign. It was most likely a Proposition 65 labeling warning. However, what in the world do you do with that information? How did posting that sign change any behavior? Could I have done anything different to avoid the jet fumes?

prop65 jet

It reads, “Warning. Chemicals known to the State of California to cause cancer, birth defects and other reproductive harm are present in the jet engine exhaust fumes from jet fuel, and exhaust from equipment used to service airplanes. Sometimes these chemicals enter this jet bridge.”

In much the same way, sometimes our warning to employees is pointless. What can they do different? What is the point of telling them something if there is nothing we can do different?

The global harmonization system (GHS) is being implemented in the US by the end of 2013. By 2014 you must train your employees on the new changes to the (Material) Safety Data Sheets (SDS, now). (BTW, there are also some other things you must do).

The message I am trying to make (double irony, I know) is when you are training your employees, how do you measure the effectiveness  If they “sign in and say they were in your training”, were you effective? Here are some suggestions, which might help to measure the right thing:

  • Questions. This ___ number of the audience asked ___ questions.
  • Feedback. I received ____ # of suggestions for the next training.
  • Changes. They are going to implement ____ changes to their workplace.
  • Secondary labeling. (GHS specific, of course) While walking around the site, I noticed ____ secondary labels with the new labeling pictographs.

I admit these aren’t the-best-suggestions-ever. But, warning someone without an alternative, method to change, or way to adopt a change, is really pointless.

Reviewing a material safety data sheet (MSDS), or soon to be called a SDS (safety data sheet), can be a useful skill. Most times the product is straightforward and gives you what you need. However, there are somethings to watch for and areas to focus to make your reviewing skills better.

To start,  make sure you have the right SDS. Match the product with the form. If is is not exactly right, find the right one. It must list the model/product name & manufacturer.

Below are some suggestions:SDS

  • What is the date of the SDS?
    • is it the most recent?
    • when was it last updated?
  • Look at section 2/3 (Hazardous components) VERY carefully.
    • google the CAS# and find the name (they sometimes hide the true-name)
    • look at the % of each component
    • what is the listed exposure limit? Is it correct? What about other recommended limits?
    • remember the hazard is only listed in this area if it is greater than 1% of the total
  • Look through each section mindful of how you will be using the product.
    • for example: if you are going to be burning the product, usually the SDS will not address these types of concerns/exposures
    • what are the required PPE during “regular use”
    • what happens if you use this product in a confined area?
    • does the manufacturer recommend air monitoring? when?
  • Familiarize yourself with the emergency procedures
    • what if it spills?
    • disposal?
    • what can cause exposure? inhalation? skin?
  • Look at the other sections with a inquisitive eye
    • do they list other chemicals, which are NOT included in the product section? why?
    • do they mention Proposition 65?
  • Finally,
    • post/make available a copy wherever it’s needed
    • make sure you know the product

It is a mixed-bag when it comes to the quality of SDS from a manufacturer. Some of them will work with you, others are a total-pain. Remember it is YOUR RIGHT to know about the products you use. If you don’t feel comfortable with the information they’ve given you, call them. OR, go find another product.

CaliforniaProp65 labelYou may have seen a product label which states that, “this product is known to cause cancer”…if used in California. (ha)

Proposition 65 is essentially a labeling rule. in 1986, California made a rule mandating anyone selling to California to label the product… if it had a serious health risk. This rule was above and beyond the OSHA reporting limit of 1%, like on a MSDS (henceforth called SDS, BTW).

The rule is actually good. It makes manufacturers tell you if there is anything hazardous in their product, or if they used anything hazardous when they made the product. (Side: If you haven’t heard, some manufacturers like to hide their ingredients, some say for proprietary reasons. Here’s an example)

More information about the rules is here. There is controversy over it’s usefulness (see here), but in this day in age, I believe you should be made aware of the information.

What usually happens is you find a SDS with no information about the product. Then, as you investigate, you find a “Proposition 65 warning”, indicating something about the product which, “may cause cancer”. So you ask, why does this happen? (more FAQ here) Well, the manufacturer used, or contains, something in their product that is hazardous. It can be a nice trail leading to chemicals which to sample for, or investigate.

The new global harmonization system (GHS) is officially adopted by OSHA. Each state run program is rolling out their acceptance of the new changes. Where I live, we have until December 2013 to train employees in this new type of hazard communication.

Honestly, I’m NOT too EXCITED about it. But, I’m trying to have a good attitude. Below are some good things which may occur:

  • Raise the level of awareness of hazardous materials & their toxicity
  • Train employees (hopefully, retrain) on how to handle chemicals
  • More training = less citations. (?) OSHA’s top ten citations include #3 – hazard communication. Maybe people will actually do the training?! (my guess is that there will be more citations)
  • Consistent information worldwide.  All UN countries should have the same format. (this might take years)
  • Proprietary information will be more visible on the SDS. In the new rules, manufacturers are required to list the % of their proprietary ingredients.
  • Pictograms! They’re so cool. My favorite is the exploding person.
  • Maybe this is my favorite?!: Manufacturers will have to look again at their products and classify them according to the physical & health criteria. Nowadays with more relevant information from worldwide occupational exposure limits, it might help make employers aware of the hazards.
    • This might help OSHA enforce newer exposure limits (other than the 1978 AGCIH TLVs).

How do you plan on training your employees? If you need help, contact me here.



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.

After performing an industrial hygiene survey (air monitoring), have you considered when you should resample? Here are some considerations that might help you in determining when.

  • Are there specific rules that state when you must resample? For example, the construction lead standard (1926.62) states that you must resample yearly (or actually, that you can only use relevant results for one year).
  • Has the process changedsince the last time you sampled? This one is hard to determine. Lot of things can change air monitoring results, here’s a “starter list” of things that can change a process.
    • Different employee?
    • Time of year? Summer versus winter? (closed up/open and humidity)
    • Is a new tool in place?
    • Has the ventilation changed?
    • Have new controls been put in place? (administrative, systems operations)
  • Has the product changed? Check the safety data sheet (aka MSDS).
  • Are more (or less) employees exposed to this hazard? This might change some assumptions you have made about your risk.?

If you have air sampling performed, make sure you have a written report of your findings. Laboratory results without an explanation of how they sampled, where, # of employees, process description, PPE used, safety data sheets, etc….is worthless. You may remember is well enough, but OSHA will have a hard time believing that it is a similar exposure the next time you do the “exact same thing”.

Having this report and sharing it with the employees will fulfill (part of) the hazard communication standard requirement to employees.




The big industrial hygiene conference (AIHCe) is held in a different city each year. This year was Indy, Indiana. Below is my personal top ten list  of “lessons learned” from last week.

  1. IH’s need to do a better job of sharing. We don’t share data, experiences, information, knowledge or our ideas well.
  2. CPWR is trying to share. Center for Construction Research & Training.  I’m looking forward to seeing their published independent review of local exhaust ventilation (LEV) units.
  3. The minimum exhaust rate for a portable exhaust unit must be 106 cfm (cubic feet per min) to capture particulates (dust, silica) during tuckpointing with a 5 in grinder (but it’s also a good rule of thumb).
  4. Asphalt milling machines are still a huge silica problem. Water controls are NOT enough. You need a local exhaust system too. (here’s an earlier post I made on it)
  5. GHS Safety Data Sheets – it’s not as complicated as you think. There are some significant changes, but don’t worry, OSHA’s here to help (ha). Seriously, more information will be available soon.
  6. Ignite. Have you seen these before? Short, stand up speeches about their ideas/passions. Similar to TED. Some were better than others. But, did I mention they were short?
  7. Committees. Be careful when you open your mouth. My idea was so great, they are making me do it.
  8.  ANSI A10.49! A health standard for construction. Great idea, but lots of work.
  9. Check out Environment for Children. I don’t know much about it, but they have a great mission.  Believe me, in the US, we’re WAY ahead.
  10. Presentation. It’s all up to you to make it. I will not cast blame on those who had bad presentations. BUT, it reminds me that I should work on this skill. Even if you have something good to say, if you give a horrible presentation, it’s likely no one will notice. On the other side, if your presentation is good, people will listen, even if you’re talking about nothing!  My favorite of the week: Dr. Mike Morgan (Univ. of Washington) on Chromium VI. He was very factual, not too flashy, and make the point without needless details.


Here are the questions I’ve been hearing in regards to the MSDS changes with respect to the new GHS (globally harmonized system of classification & labeling of chemicals)…

I am going to keep the answers REALLY short so you’ll actually read it. Keep in mind, I’m leaving some information out.

  • What do I need to do?

As an employer you need to train your employees on how the new MSDS will look.

  • How soon do I need to comply?

For contractors, you’ll need to train your employees by Dec 1, 2013.

  • What is it?

It’s a universal (global) method to make MSDS have more information and make them all look the same.

  • Why are they doing this?

Well, MSDS’s are very good. They’re supposed to be written with the same 15 sections with no-blanks. But, some people don’t do a very good job. Or, in some cases, do an really good job of hiding harmful chemicals, but, legally cover themselves.

  • Where can I get help? Right now?!

There will be FREE training (you may have to search for it though) and more information being published. This is a topic you can learn and present to your employees. Since the deadline is a year and 9 months away, you have some time.

  • Ok, do you have any places for additional information?
Yep. Federal OSHA has a fact sheet.  EHS Today has an article. OSHA has a guide. AIHA press release.
  • Is there information in spanish?

OSHA has some info here.

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