The transponder coded safety switch CTP with door lock function has been extended and approved for use in potentially explosive environments in accordance with the ATEX directive. In the CTP-EX version, the safety switch can be used in Zone 2 (gas environment) and Zone 22 (dust environment). Various design measures have been taken on CTP-EX to meet the high requirements that may be used in explosive environments as well as the requirements of ATEX instructions. For example, additional protective covers are provided and measures are taken to prevent sparks. Like all safety switches in the CTP-EX series, CTP-EX has a locking force of 2600N. More than 20 devices can be connected in series. In addition to meeting the requirements for use in Atex Zone 2 and Zone 22 environments, CTP-EX meets the requirements of Cat's EN ISO 13849-1 standard. 4 / PL e and EN ISO 14119 for Type 4 switches with high coding.