Radioactive symbol overlayed on a high voltage, laser, biohazard, and slippery floor symbols. Original title caption: The warning diamond on the Materials Safety Data Sheet for this stuff just has the "😰" emoji in all four fields.

xkcd is nearly always fabulous, but this was the first in a long time that made me laugh out loud. I still remember slipping in high school chemistry class on soap we’d made, and the resulting bruises to my arse and dignity.