The application of the LEP allows the search of a rapid way of the limits of professional exposure for chemical agents in Spain adopted by the INSST after its approval by the National Commission of Health and Safety at Work and are updated annually. The objective of this application is to facilitate compliance with Royal Decree 374/2001 which establishes the employer's obligation to assess, among others, the risks arising from exposure by inhalation to a dangerous chemical agent, as well as the