I know it’s not safe, but I’ll just be careful

By Don DeCaro, Senior Instructor and Consultant

Yes, that is the title of this article and the start of a most “un-excellent” adventure of mine that occurred many years ago. It started with my wanting to finish up some simple water-testing: pH, hardness, salt, TDS, and finally an ammonia determination. The test for ammonia uses Nessler’s reagent (an aqueous solution of potassium iodide, mercuric chloride, and potassium hydroxide, used as a test for the presence of ammonia).

10:40 AM - I want to finish this testing so I can go out to lunch with the crew at 11:00 AM. It is a half-hour lunch that usually goes from 11 – 12:30 PM. Once back from lunch, all I need to do is clean up the glassware, write up the report and day is done.

Hey, all I need to do is pipette one ml of Nessler’s solution to 50 ml of test solution, mix well, wait the prescribed amount of time and take a colormetric reading to get the ammonia value – easy.

10:42 AM - I can’t find my squeeze bulb to pipette the Nessler’s solution – drat! Watching the clock ticking furiously, I search around, but I can not find any bulb nearby.


10:44 AM - Knowing that the storeroom is closed for lunch at this time, I made a fateful decision; I would pipette the Nessler’s reagent by mouth. In the past I have pipetted water by mouth with no problem. The only difference is that this would be a hazardous solution. So I said to myself: “I know it’s not safe, but I’ll just be careful.”

10:50 AM - I held the bottle of reagent and noticed that the bottle was only 1/5 full. I muttered to myself that I should be real careful not to lift the tip out of solution while siphoning the solution; it could bubble up and “hit” my mouth.

10:55 AM – Here I go; I start to siphon up the nasty solution by mouth just as the “boys” come by the doorway to my room. “Hey!” they yell, “let’s go already.” As they yell, my head tilts upward, lifting the pipette out of the solution.

10:55 & ½ AM - Several drops splay upwards and enters my mouth. I could feel the enamel of my teeth dissolving.
My throat muscles constrict as if King Kong was squeezing my throat. In the pain, I barely manage to lower the bottle of Nessler’s reagent to the bench, gagging along the way.

10:56 AM – “C’mon,” they yell in unison, “stop fooling around and let’s go.” They proceed to exit the lab and enjoy lunchtime.

10:59 AM – I recover somewhat from my incident, rinse out my mouth and sit quietly in a corner of the room. I actually reflected on what had happened and why I took such a chance. I really balanced the benefit of not following a prudent practice vs the risk taken.

11:00 AM – A Safety person was born at that moment.