There is no ashtray in the plane bathroom. Why is it forbidden to take off?

Civil aviation regulations clearly stipulate that no matter whether smoking is allowed in any other area of the plane, a detachable ashtray must be set at the entrance side of each toilet door or in a conspicuous position near it, but an ashtray can also be shared by several toilet doors, as long as it is easy to see from the side of each toilet near the cockpit. In addition, toilets must have "No Smoking" or "No Smoking in Toilets" placards, which are located at the obvious entrance doors on each side and belong to the mandatory equipment within the flight safety scope. The real reason is actually very simple. The ashtray in the on-board toilet is not for passengers to smoke, but a safety device in the cabin to put out cigarettes in the hands of some passengers who smoke illegally. Once it is found that someone really smokes, the flight attendant must put out the cigarette with an ashtray at the first time to ensure flight safety. Think about it carefully, if someone really smokes on the plane and then throws cigarette butts in the trash can filled with paper products in the bathroom, it is very likely to cause a fire, and the consequences are unimaginable. Moreover, this is not an alarmist. Smoking on the plane happens from time to time, and even has caused serious consequences. Chinese and foreign air crashes in history also tell us with bloody lessons that the bad behavior of smoking on board led to the plane crash. 1973, a flight from Rio de Janeiro, Brazil caught fire because a cigarette butt was thrown into the trash can and eventually crashed, killing all 123 passengers on board.

Reference: Hu Zhi/Question/51459956/WER/1502508