I was using a compressed can of tetrafluorethane to clean dust out of my computer. The instructions on the can indicate only to use it upright and not to tilt it or invert it. Not really thinking, I blew it downwards into my case and a liquid sprayed out. It got into an area where it’s not really practical for me to wipe it off.
The can warns about using it in a ventilated area, avoiding contact with skin and eyes, etc. So I’m wondering if it’s safe to simply let it sit in a well ventilated area for a while. Will that let all the toxic stuff evaporate? Or will it leave some sort of potentially harmful residue? Do I have to actually get in there and clean it up?
It isn’t very toxic, though if it blows all the oxygen away there’s nothing to support life until the air mixes again. And it should evaporate almost too fast to see. If anything feels damp, it is almost certainly because this stuff evaporated so fast it created enough of a chill to condense water out of the air, or even frost. I think you should treat this situation as though you got something very cold and possibly made water condense on it, and not worry about toxicity unless you are trying to do the whole thing while hiding inside a trash bag.
Huh. Well the area where I sprayed it looked wet/slick and I assumed it was the liquid form of this substance. I left it where I’d cleaned it (outdoors) for maybe 20 minutes and it still looked a little wet.
It’s 100 degrees and 9% humidity, so I’m surprised it even managed to find moisture to condense…
Yeah, I dream of the lack of humidity in Vegas. I was there for the one and so far only time in my life last June. Hot as hell, but strangely it seemed like what I’ve wanted my whole life. I got back to southern Ontario at 1am and it was only about 12C, but I could really feel the humidity, even after only 3 days
edit: right now it’s 23C with 78% humidity, not that hot, but we are currently on the way to the coldest summer in history, since last summer
As your link states, the boiling point of Tetrafluoroethane is -26.3°C.
It’ll be gone even before your board warms back up to RT.
Exposure is nothing to worry about unless you make a daily habit out of it or some such.
9% relative humidity at 100 F implies a dew point of 34 F or 1 C, which is way higher than boiling tetrafluoroethane’s boiling point. It wouldn’t have had the slightest trouble finding water to condense. Wouldn’t even break a sweat, you might say…
Note that there is other “junk” (I have no idea what - oil?) in compressed “air” dusters. If you turn them upside down and blow them onto a clean surface, they live a residue, and it’s not condensed water.
Most air dusters are pure air and HFC propellant, but there are some that contain hydrocarbons (around 5% of the total propellant load). n-butane, in particular, can stick around if the temperature is low enough (boils at -0.5 degrees C).
They want ventilation because if you dispense a large quantity of it, it presents an asphyxiation hazard due to displacement of breathable air.
They don’t want it on your skin or eyes primarily because if you dispense liquid instead of gas (e.g. can is upside down, or you shake/wiggle it while dispensing upright), the boiling off of the liquid can cause rapid frostbite. Painful to the skin, potentially life-changing to the eyes.
I would avoid using it on live electrical circuits, since any condensation may cause electrical short-circuits. Maybe not a big issue on your nice rugged desk lamp, but a super-sensitive computer chip might fry if electrons go where they’re not supposed to. Power down, spray like mad, give things a minute to dry/warm up, then power up.
