49 CFR §228.319

1. (a)Number. Each camp car that provides a sleeping facility must contain at least one functioning lavatory for a total of one or two occupants and an additional functional lavatory if there is a total of three or four occupants.
2. (b)Water. Each lavatory must be provided with hot and cold potable running water. The water supplied to a lavatory must be from a potable water source supplied through a system maintained as required in § 228.323.
3. (c)Soap. Unless otherwise provided by a collective bargaining agreement, hand soap or similar cleansing agents must be provided.
4. (d)Means of drying. Unless otherwise provided by a collective bargaining agreement, individual hand towels, of cloth or paper, warm air blowers, or clean sections of continuous cloth toweling must be provided near the lavatories.