Nude models at a US art school have voted to join a union as a means of forcing the university to pay attention to professional hazards such as cold rooms and charcoal dust.
Administrators at Moore College of Art and Design in Philadelphia, which enrols only women, said it was news to them that models were experiencing poor working conditions.
They opposed the union bid, saying the models were independent contractors and not employees, but government mediators disagreed.
In all, seven of the 13 eligible models have so far voted to join the American Federation of State, County and Municipal Employees, which also represents city workers and zoo employees. The union hopes to organise other models who pose for art classes in the Philadelphia area.
Labour officials said they knew of no other schools at which nude models had organised. Moore pays models $11 (£7) an hour. The models say that is not enough for work that includes holding poses for hours at a time.
They also want private changing areas, better temperature control, cleaner studios and improved ventilation.