Just a one-off that happened a few nights ago. My son and I changed the radiator in my '93 Grand Am. A crack. It was easier to disconnect the A/C line to work the rad in and out.I didn't even use the A/C this year and don't care about it anyway since I only do short street trips in the car. He figured it had leaked out since we charged it a couple years ago. Nope. Seemed to dump a full charge. I yelled about that but it was too late because he had gone whole hog on the connector nut. We had a wicked kerosene heat going about 5 feet away on the floor, to take the chill off and warm hands. Temp was right near freezing. Typical Kero-Sun, a 23k btu. About 5 minutes after the R134 dump, my son started sniffing and looking around. My eyes started burning, and then I started choking. Acrid, like burning electrics, but a different smell. Hit him too. It was pretty bad on the lungs, as bad or worse than electrical fires I've experienced. Quickly opened the garage door to get away, but air was okay about 10 feet from the heater and after a couple minutes it burned off and we closed the door and went back to work. Never anything visible. Weird how it was delayed. Figure some of it, maybe just a tiny amount, soaked into the wick and had to heat up real good before it burned off. Anyway, something that shouldn't ever happen, but did anyway.