People would occasionally ask me what was the worst chemical I had ever worked with. My first thought was always an evil mixture of hydrofluoric and nitric acids widely used in the semiconductor industry to dissolve silicon metal. Both acids can burn a hole through your skin down to the bone, but the hydrofluoric acid’s nasty twist is that it anesthetizes the nerves so you may not even be aware of what is happening until you see a hole in your skin with a white thingy at the bottom. (Note that it is hydrofluoric, not hydrochloric acid.)
Another thought is several research chemicals that came in a sealed glass tubes labeled “Warning—STENCH.” What’s the big deal? we thought. Chemists are used to bad smells.
I can only tell you, you have no idea how bad something can smell. Our research was on improving flashlight batteries, but we quickly realized these chemicals could never be used no matter how well they performed. Our research leader flushed them down the drain and left the water run for about a half an hour, but the smell still permeated the entire laboratory building. He swore us to secrecy.
The worst would have been benzene if we knew it was a carcinogen, but no one knew that in those days. It had a pleasant smell of shoe polish. You probably can’t recall what shoe polish smells like, but if you smelled benzene, you would immediately recognize it. If a bottle of benzene was open, we would often take an extra whiff just for the pure pleasure of it. (Our research leader did die of cancer while still in his 30s.)
But for the absolute worst, I vote for the carbon black that we used to make up the experimental batteries.
The carbon black came in huge bags that only weighed about a pound. The bag weighed more than the contents. The carbon black was soot collected from burning gas jets.
To store it in the laboratory, we would empty the bag into a trash can in the parking lot on a very calm day. Even then, the person assigned the job, usually me, would be enveloped in a black plume of floating carbon. Replacing the lid was like trapping a genie inside.
In the lab, we would often make up an experimental mixture calling for a gram or two of carbon black. The procedure was to first seal the air ducts and hoods and block the doors so no one would inadvertently walk in. Their wake in the air would be a disaster. Then, slowly . . . slowly . . . step-by-step . . . inch-by-inch . . . approach the can with a big beaker and lift the lid. Pause, as a black cloud rises ominously from the interior. Slowly dip in the beaker, cover it with a sheet of paper, and weigh it. We soon learned how much the volume weighed and skipped the weighing step. If the full beaker contained two grams of carbon black and the recipe called for one, we used half. Getting it more exact was beyond human endurance and was not crucial, anyway.