On Feb. 2, a glass waste bottle exploded in a Texas Tech University teaching laboratory, injuring three undergraduate students and a graduate teaching assistant. TTU has nowposted its investigation results online.
In short, a nitric acid wash step was eliminated from the lab but the written instructions were not revised (I don’t know how this was communicated–with a verbal “skip step X”?). Nitric acid waste then wound up in a bottle with methanol and dimethylglyoxime, reactions ensued, pressure built up, and the bottle exploded when a student later tried to open it.
The good: “All students and personnel were wearing appropriate personal protective equipment including lab coats, safety goggles and gloves.”
The bad: The waste bottle was labeled with HNO3, HCl, methanol, and dimethylglyoxime. Clearly the lesson is not getting through to people that you can’t mix nitric acid with organics. Also, people need to keep written procedures up to date. It’s not hard to see how a verbal instruction would get ignored in favor of what’s written down, not to mention what happens if the person who historically runs the lab is out sick or has left the department.
TTU is surely not the only institution challenged by these things. I would also argue that TTU should be commended for continuing to make its incident information available so that others in the academic and chemistry communities can learn from the experience.
TTU’s action items to move forward:
1. EH&S will be providing pressure relief caps to waste storage bottles that contain inorganic acid wastes.
2. Faculty, instructors and TA’s should communicate unique safety concerns at the beginning of teaching labs prior to any experiments. The safety concerns should reflect the hazards posed by that experiment.
3. Responsible individuals over teaching labs should revise their teaching procedures regularly and review for possible hazards that can be eliminated. Any additions or deletions should be reflected in handouts provided.
If people could use nitric acid + organic solvent visual for training purposes, this YouTube video seems useful: