As other part of China, There were two toilets available at every end of car. On one side is an Asian style toilet and on the other side is a Western style toilet. Over all they keep it very clean and toilet paper is available. but please never use it at station area, unless you were very emergency.
There are neat bathrooms and sink areas in the Tibet train. The attendants always keep the sink areas reasonably clean. Each sink area is equipped with three sinks which have the push type water faucet. The sink areas are always busy in the morning because it is shared by 32 people. It is better to buy a towel at a supermaket before you get on the train for there is no toiletries and hygienes supply on Tibet train.