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A Scientist, an Actor, a Businessman, and Unknown Toxicity

Many good jokes have a common setup to them. That setup involves a unique group of individuals and some sort of humorous interaction that ends with a punchline. So here is my setup for this blog. What do a famous scientist, an award-winning actress/comedian and a well-known businessman have in common? Let’s look at a quote from each of them.

  • From Werner Heisenberg, the scientist, and his book Physics and Philosophy: The Revolution in Modern Science:
    • Whenever we proceed from the known into the unknown we may hope to understand, but we may have to learn at the same time a new meaning of the word ‘understanding’.
  • From Gilda Radner, the actress/comedian:
    • Life is about not knowing, having to change and making the best of it, without knowing what’s going to happen next.
  • From Warren Buffet, the businessman:
    • Risk comes from not knowing what you’re doing.

Now, I don’t have the best punchline but there is a common thread in each of these. It is about the unknown.

As authors of Safety Data Sheets (SDS) and labels, when researching ingredients there are times when there are no acute toxicity data in the literature on an ingredient. When this happens, alarm bells should ring. There is a very specific thing that has to happen when ingredients have unknown acute toxicity. When that ingredient is a part of an untested mixture at a relevant concentration, and the mixture is classified as acutely toxic, it presents a unique situation under OSHA HazCom2012. Per Appendix A, Section A.1.3.6.2.3 when this happens the statement “x % of the mixture consist of ingredient(s) of unknown acute toxicity” is required in Section 2 of the SDS and on the label. What has never been truly clear to me in the regulation is how to actually use that phrase.

Since that is the case with the current set of documents I’m working on, I wanted to see if OSHA had given any more guidance on the topic. Per the website under the FAQ’s drop-down tab,

Classifiers can present the unknown acute toxicity information on labels and SDSs either as a single statement or as multiple statements, where routes are differentiated. If there is an unknown acute toxicity by more than one route, and the classifier chooses to provide one statement in order to save space on the label or SDS, then the route with the highest percentage unknown toxicity will be used in the statement. The single statement on the label or SDS would state that:

“x % of the mixture consists of ingredient(s) of unknown acute toxicity.”

Because it is possible to have ingredients with unknown toxicity for more than one route (e.g., oral, dermal, inhalation), differentiating the unknown toxicity statement by route is recommended.1 As such, classifiers may also communicate the information as:

  • x % of the mixture consists of ingredient(s) of unknown acute oral toxicity,
  • x % of the mixture consists of ingredient(s) of unknown acute dermal toxicity,
  • x % of the mixture consists of ingredient(s) of unknown acute inhalation toxicity.

1 Revision 4 of the GHS has clarified that the statement of unknown acute toxicity should be differentiated by route, see GHS Rev. 4 (or current version) paragraphs 3.1.3.6.2.2 and 3.1.4.2, and OSHA recommends classifiers follow this guidance.

According to this, I can choose how to use this statement. There is the option of using one blanket statement or breaking out the individual routes of exposure. However, beware of the footnote! The footnote says, “Revision 4 of the GHS has clarified that the statement of unknown acute toxicity should be differentiated by route, see GHS Rev. 4 (or current version) paragraphs 3.1.3.6.2.2 and 3.1.4.2, and OSHA recommends classifiers follow this guidance.” I added the bold and underline to make my point. Even though at the start of the answer it appears you have options as an author, OSHA recommends we clarify by individual route. If you want more information, you can read the full Letter of Interpretation here.

So, now I have my answer for how to proceed. There will be a few more phrases in Section 2 of my next series of SDS. As always, ICC Compliance Center is here for all of your hazard communication needs.

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