Since September 2007 all NSHEV (natural smoke and heat exhaust ventilators) intended for the European market have to bear the CE mark.Testing and certification basis are the tests specified in the standard DIN EN 12101-2 "Specification for natural smoke and heat exhaust ventilators". If the NSHEV bears a CE mark, then this device can be assumed – according to legal regulations – to have been subjected to all the necessary tests with a positive result.