We have a friend who loans out her pressure washer like it's a garden hose. Not so fast! Besides damaging decks, siding, brick or driveways, a wayward jet stream across a leg can cause serious, if not permanent, injury. According to Mary Pat McKay of the American College of Emergency Physicians, once the stream of water lacerates tissue, there's the hazard of cleaning fluids being injected into the soft tissue.
"The tissue can just die because it's sort of blown apart by the pressure and then by the presence of the [cleaning] fluid in the tissue."
Yikes! Take heed, don't let kids or teens get their hands on the pressure washer. Well, you could possibly train a responsible teenager how to clean off the driveway, but only after clear instructions.
More on pressure washer use and safety at The Washington Post.