Do not leave wrenches unattended clamped to pipe as demonstrated here.
This can result in injury by striking persons or equipment at lower levels and become trip hazards.
No loose items are to be hanging on pipe, conduit, railing of lifts, or ladders – even if you’re standing next to it. All tools, equipment, and material must be secured properly when not in use. If you have to step down off of the ladder to retrieve material or leave the area, take the wrench with you no matter how many seconds it takes. Before relocating a ladder always look on top for loose tools.