In the Air Force forensics lab I used to manage, we had a liquor license on file with the BATF. My Class 10 clean rooms were scrubbed using Radiac Wash, then rinsed with de-ionized water. The final rinsedown was accomplished with 200 proof ethanol, we used Nalgene squeeze bottles and literally doused every nook and cranny of the clean rooms with the stuff, allowing it to air dry through the HEPA/ULPA filtration systems. I went through 15 gallons of pure, 200 proof ethanol each month. We bought it at a distiller in Oakland, and drove the van, full of ethanol jugs, back to the lab in Sacramento.
That stuff is wicked. I sent a couple of my airmen back into one of the rooms to turn it around for incoming samples, and they got the bright idea to turn off the air cabinets in the fume hoods, so they could scrub them down longer before everything evaporated.
That was around 0800. By 1130 I was starting to wonder how they were doing, because they hadn't called me to let me know they were done. By 1200, I donned my Tyvek bunny suit, overbooties, hair net, and mask, and progressed through the air showers towards the clean room in question.
I couldn't see the two guys inside the room as I stood outside the door, they weren't visible through the window!
I burst into the room, and there they were, lying on the floor, propped up against the fume hood legs, laughing their butts off. Each of them looked like a piece of railroad rolling stock graffiti. They had taken the black Sharpie markers we used to label sample bags, and scribbled artwork and verbage all over each other, including their faces, eyeglasses, Tyvek bunny suits, and so forth. Each had a nicely-drawn moustache and goatee on their faces, extra eyes drawn on their Tyvek hats, you name it.
They had cleaned the rooms, alright. When they rinsed out the fume hoods with the 200 proof ethanol, they stuck their heads inside the fume hoods to see where they were rinsing. Without the air cabinets operating and pulling air through the hoods, my two airmen were inhaling ethanol fumes without benefit of dilution.
I had to get them on their feet, out of their clean room garb, and escort them to the break room, where they spent a couple hours drying out before I sent them home for the day.
When we decommissioned the lab in 1999, several gallons of that 200 proof ethanol made its way into the 55 gallon drum of jungle juice we mixed up for the final closing party. Wow!!!
The rest went to the PRK state crime lab for use in their own lab processes.
