I've been quizzed many times as to whether I have lipstick, and been informed that "if you can pour it or smear it, then it's a liquid. You can smear lipstick, so lipstick is a liquid."

However, I once had a container of Johnson's baby powder confiscated at security, on the grounds that "you can pour it, so it must be a liquid."

Maybe it depends on the individual screener's state of mind on the day - don't expect it all to make sense!