Límites de exposición (LEP) is a free Android app developed by INSST that provides quick access to professional exposure limits for chemical agents in Spain. It is updated annually after being approved by the National Commission on Safety and Health at Work. The app aims to help employers comply with the obligations set by the Royal Decree, which requires them to evaluate the risks associated with inhalation exposure to hazardous chemicals, among others. The app allows users to search for information by CAS or CE number, agent name, or alphabetically. However, for the first option, users must know the exact number. For additional information, such as toxicological documentation or air contaminant sampling sheets, users are directed to INSST's website. An internet connection is necessary for the app to function correctly.