Aside from making sure your people are competent and well trained, not much is often done to prevent spills. Engineering controls such as secondary containment, fume hoods, capped reagent bottles, etc. work well when people remember and plan to use them. All too often, we see good chemists forgo extra safety steps for speed or just plain old laziness. Sometimes, people get badly hurt not because they were bad chemists or bad scientists, but because they really needed to catch the 6:40 train that day.

What we need are more safety devices that prevent the accident caused by a failure of the preventative safety measures from being very dangerous. For example, take these safety-coated reagent bottles from VWR. They have some plastic coating (PVC I think) outside of the glass to prevent spills even if the glass shatters. Sure some solvents would eat through the coating, but it would still buy you time to contain the spill, or evacuate the room if necessary.

Recently, with LBL’s current safety kick, our lab ordered 40 of these babies to replace our older reagent bottles. Interestingly though, the coating is really hard to see. In fact, when we first examined the bottles there was a dispute between some lab members as to whether we received the correct shipment or not.

Here is how the bottle looked, next to a typical graduate student size scale:

Being scientists however, Mitch and I knew that we couldn’t just take VWR’s word that we now had safety-coated reagent bottles.  We needed to test whether it really had the safety-coating, whether the coating would actually stay intact after an impact strong enough to break the glass inside, and whether the coating would feel weird if we poked with our finger.







So, using my safety training, I put the reagent bottle into a plastic bag, and put the plastic bag inside a phototray. Note the secondary and tertiary containment.






I went and found a big wrench, donned my safety goggles, lab coat, nitrile gloves and put the soon to be destroyed bottle durability testing apparatus into a fume hood with the sash half open.  I then proceeded to smash it to pieces. It was a good day of science.

Here is the result after a good beating. The safety-coating is quite clearly visible now, along with the area where the hole would be, if the coating wasn’t still covering it. The interior glass shattered as expected, but the safety-coating simply flexed a bit and recovered. Also, no sharp pieces of glass pierced the coating, so the contents of the bottle would have been contained. It took a significant amount of effort with some sharp tweezers to illustrate the intact film of the coating. We also confirmed our hypothesis that poking the film with our finger would feel weird. The bottle met our expectations in all tested categories. It also looked really cool and took a great picture.

So in our effort to make the lab safer, we tested and confirmed the usefulness of these safety-coated reagent bottles in an easily repeatable scientific experiment. Tests would have been done in triplicate, however funding was abruptly cut off when we attempted to share our findings with others in the lab.  We recommend the safety-coated bottles for use throughout the chemistry lab. All waste was disposed of in coordinance with EH&S protocol.

I didn’t know that Avogadro’s constant has changed slightly. IUPAC and IUPAP were embroiled in controversy over whether to consider the mole to be the number of oxygen atoms in a sample of oxygen-16 or as the physicists preferred, the number of atoms in a fixed sample of carbon-12. By adjusting the standard, the atomic mass unit slid a little, so that hydrogen was no longer 1.0000 amu, but became 1.0083 amu. To me, Avogadro’s number was a constant, an unvarying and mysteriously established number in the universe like pi or Euler’s number. In reality, it’s nothing more than the definition of an arbitrary unit of measure unvarying only so long as the units chosen to measure it. Technically so are approximations of pi and Euler’s number, since they are written in the base 10 system we use for counting.

The physicist Richard Feynman, arguably well known for his antics as much as his science, wrote of “fragile knowledge” in his book, “Surely, You’re Joking Mr. Feynman”. I’ve only recently read it, I sort of happened upon it at the bookstore. He recounts how he capriciously got some people to look in astonishment over a french curve and note how the lowest point at any of its curves was designed to have a horizontal tangent, no matter which way it was turned. The trick was of course, that it wasn’t designed that way, the lowest point of any curve has a slope of zero! Yet here were a bunch of students who had taken calculus and were all using pencils to establish for themselves this peculiar whim of french curve makers. The story struck a chord with me, since it set the lower bound for the harm caused by fragile knowledge: Looking like a fool.

Yet this is the way I was taught the number–as a number–not as a relationship or standard. When you think about it, this is the way we’re taught many other things, like pi as 3.14, instead of  “the ratio of the circumference of a circle to its diameter”. My question is, why insist on this sort of teaching? So that students can focus on calculations and thereby “learn what they need to know?” That’s foolish and short-sighted, as demonstrated by my experiences fooling teachers into believing I knew anything about stoichiometry and getting Bs (which stood for Better than I deserved). So what if the time available in a semester or school year is limited, isn’t the measure of how well something is “taught” the extent to which it is “learned” (as in- not simply memorized)?

In fact it was only after reading Asimov on Chemistry a long time ago, that I was able to finally get a handle on constants, the real tragedy being that this information is not something I could have gotten from a class or even my college level chemistry textbook. I could not have even developed an interest an chemistry (or math- another story) were it not for my readings outside the classroom. It’s easy to understand why it’s important for students to learn to manipulate numbers in chemistry, but what is the point if they’re doomed to be obsolete calculating machines who can give you the recipe for 1M sodium acetate, but have no clue what that information means?

When I was taking organic chemistry as a sophomore, the lecturing professor encouraged students to ask questions in his class.  His reason?  “If you have a question about something, chances are that someone else in the class has the same question.”  Likewise, I believe in open communication, particularly in learning the rudiments of organic chemistry.  Anyone who has taken a class with me will instantly recognize my trademark closing inquiry: “does anyone have any questions, comments or concerns.”  I give students one last chance to bring up any issues before the lab begins.  Usually, 95% of the time you can clearly hear a pin dropping on cotton during this time. 

The problem I’ve encountered over the past couple of years is the lack of preparedness by the average student.  Granted, the procedures will deviate from what’s in the book on occasion, but these concerns are addressed either in the prelab lecture or in my final instructions right as the lab period begins; I also leave notes about these issues on the whiteboard.  Remember the old cliché, “there’s no such thing as a stupid question”?  Some students recidivistically abuse this rule to the point of criminality.  Here are a few conversations between students (S) and teaching assistants (TA) over the past few years of teaching organic chemistry.  I’m sure you can supply your own examples.

S:            “I spilled my product in the hood.  What should I do?”

TA:         “A celebratory dance?”

S:             “My book says to add…um…sodium…brine…when the color changes.  Do I add it?” 

TA:          “Did the color change?” 

S:             Pause.  Smile.  “Yeah.” 

TA:          “Congratulations!  You answered your own question.  You’re one step closer to being a synthetic organic chemist.”

S:             “No.  This is my last semester of chemistry.”

TA:          “Really?”

S:             “What’s the molecular weight of anisole?”

TA:          “What’s the chemical formula?”

S:             “C…9…8…7…H…”

TA:          “What does your book say?”

S:             “I didn’t bring it.”

S:            “Can I go to the bathroom?”

TA:         “You’re in college.  You can do whatever you want.”

S:            “So, I don’t have to do the lab if I don’t want to?”

TA:         “I don’t care.”

S:            “So you’ll gimme an A?”

TA:         “No, I don’t care if you do the lab or not.  But you have to do the lab to get an A.”

S:            “That’s not fair.”

S:             “The book says use ‘dichloromethane,’ but there isn’t any in the hood.”

TA:          “You’re better off using ‘methylene chloride.’  It’s better for the environment.”

S:             “Is NMR-chloroform a halogen?”

TA:          “What do you think?”

S:             “I think it’s halogenated…no, wait, it’s non-halogenated.”

TA:          “Why?”

S:             “Didn’t you say ‘H’ is replaced by a ‘D’ or something?”

S:             “I have a question.”

TA:          “Okay.”  

S:             The student holds up a flask with a boiling stick in it, waiting for an answer.  “What should I do?” 

TA:          “Yes.”  He walks away.  The TA makes his way around the room and returns to the student 20 minutes later.

S:             “Should I add the hydrochloric acid or the sodium stuff?”

TA:          “Yes.”

S:             Sigh.  “That’s not helping.”

TA:          “True?”

S:             Sigh.

TA:          “Oh, wait, you wanted me to say ‘no.’”