"Gatekeeping" in Intro Chem Lab

Over at Chemjobber, there's an interesting discussion around "gatekeeping" - intentionally using introductory science courses as weed-outs to restrict access to higher-level material - and whether anyone actually does this in practice. Although I don't think of my experience in these terms, I'll relate my recollections and let readers judge for themselves.

Stone walkway, 2014

At Big State University, I was part of a teaching assistant (TA) team tackling Chemistry 101 lab. These were classic experiments: density, dilutions, diffracting light, quantitative analysis, titrations, measuring exotherms. TAs not only ran labs, but lectured beforehand, graded reports, filled out student evaluations, and tallied final grades. 

While the content wasn't enough to weed out dedicated students, the lab policies certainly may have been. The implied ideology went: "if you can't follow these rules now, you'll never cut the higher-level labs." 

Pass in a report 1 minute past the start of lecture? Zero. 

Handwritten report? Zero.

Blatant disregard for lab equipment? Zero.

Show up to lab without proper PPE? Go home. 

If a student had not replaced broken glassware by semester's end? Fail.

Evidence of plagiarism from the lab manual or suspected from others' reports? Fail. 

Miss the final exam? (Yes, a final lab exam...) Fail.

Though the TAs tried valiantly to corral teach the ~400 students who came through our section each semester, my honest memory was that we usually kept fewer than 250 by term's end.

WWWTP - Lab Signs Edition

From the Sept 2014 issue of Wired magazine:

I understand that magazines require flashy, highly-posed photographs to move copy.
That said, did no one in the Editor's office notice all the warnings on that hood sash?
They read:

"Wear proper PPE (Goggles, Gloves, Protective Clothing)"

"Always properly label your chemicals, including your initials. Any unknowns will be disposed of as Hazardous Waste"

"NO STORAGE"

As far as I can tell, the researcher pictured is in violation of all three signs. Ye Gods.

Special Delivery

Look what arrived by mail in the post this morning:

As seen in several celebrity photo-shoots

OK, so I'm no Charles Atlas (or even Phil Baran) yet, but I'm getting there...
Thanks to the hard-working, fun-loving staff at Nature Chemistry!

Should Chemists 'Dress for Success?'

Chemists: Does your workplace have a dress code? Should it?

Long-time readers may remember that I opined on this very subject waaay back in the early days, noting that long-term bench work does a number on nice duds. Well, I've since switched jobs, and in my current role I'm often called upon to meet vendors, interact with inspectors, and strike up academic collaborations. So, jeans and beat-up T-shirts are decidedly out for me.

I've found that thrift stores (Goodwill, Salvation Army) tend to offer reasonably nice business casual clothes for 20-30% of the original items' costs. And, as Chemjobber has pointed out, proper lab PPE certainly helps to protect any investment you make on the sartorial front.

But out of sheer curiosity, I wonder: does anyone get to wear jeans and T-shirts past grad school?

Let me know in the comments. Thanks!
-SAO

Dirty Hood = Good Hood

Ever worked in a completely new chemical fume hood?

I have. Actually, due to moves and new facility construction, I've been (lucky?) to have three completely new hoods - hoods devoid of any smells, stains, or funny noises. All still had working baffles, legible installation labels, functioning flow meters, and bright white walls.

I ruined them all.

Chemjobber's latest post, referring to a "stinky walk-in hood," along with Pauling's lab notebooks got me thinking: How many times have I had to strip everything out of my hood, and start from scratch? I counted at least three; each one occurring in a beautiful, unsullied space.

In graduate school, I set up a sodium-mediated halogen exchange / rearrangement a few weeks after our move. After carefully flame-drying the apparatus, I greased and clamped all the joints, and set it to heat in an oil bath. I lowered the hood, and walked the ten feet or so to my desk...boom! We had a motley crew of older hot plates that didn't always heat up like you'd hope. Best I could piece together, there was an autoinitiation, followed by a massive exotherm I hadn't observed on smaller scale. Best part? After splattering my hood with compound, the flying glass cracked the oil bath, and little pieces of flaming sodium rained down around the pool of oil forming below my stir plate. Good times.
Total cleanup time: 3 days

As a postdoc, I had the "honor" of installing my own monkey bars, manifold, and otherwise arranging my virgin hood exactly as I pleased. Fast forward about a year, when I decided that a fairly exothermic borohydride reduction would go much better with a solid addition funnel. I'd covered all my bases - passive N2, massive cooling bath, flame-dried everything, the works! Except for one tiny variable: the borohydride particle size was too fine for the funnel's Teflon screw. One turn led to accidental addition of about half the reactant. Upon solution contact, the sudden gas release blew backwards into the solid addition funnel, which commenced to shoot a fine dust of borohydride onto every hood surface, including my arms.
Total cleanup time: 2 days

Later into my career, I had another heated reaction fail in stupendous fashion. The compound, a gummy orange solid, coated every surface of my hood: behind the sash, inside the light ballast, up the baffles, even down into the storage cabinets underneath. When I was finally done with that cleanup, my lab coat had been stained so thoroughly orange that we just bagged it and sent it out as waste.
Total cleanup time: 2 days

Look, all of these incidents would have been much worse if my sash had been up, or if I hadn't been wearing correct PPE when they occurred. We think about fume hoods as big vacuum boxes, but they're also great for containment of runaway reactions.

Readers: I know I'm not alone. Have a spectacular story of a reaction gone wrong? Share it in the comments.

Houston, We Have 'Level A' Protection

We just wrapped up our annual HAZWOPER training, and I've always bemoaned that it's all Powerpoint and quiz questions, without enough "hands-on" activities. Well, that certainly changed this year!

Although I'm a bit late for Lab PPE Day (this isn't really a lab setting anyway), this was my first time in a Level A suit. Wearing this feels exciting, but mildly disorienting: it's like walking through heavy snow, with both dexterity and visual impairment.

Dressing up this way gives me an even greater appreciation for everything the astronauts are able to accomplish in NASA space suits. Alas, although we tested spill kits, used gas meters, and drilled placards, freeze-dried ice cream was not served.

Stay safe, everyone!