Safety rated control relays are required to have positively driven contact elements according to IEC 60947-5-1 Annex L. Positively driven contact elements are a combination of NO auxiliary contacts and NC auxiliary contacts whose construction prevents them from being closed simultaneously. In some industries, such as automotive, requirements have been established that a safety rated control relays must also have permanently mounted auxiliary contact blocks. See page 2/70 for Control Relays with permanently mounted auxiliary contacts.
Siemens Control Relays for “Safety” applications:
All SIRIUS 3RH1 control relays (with at least 1 NC contact) meet or exceed the criteria for "Safety Control Relays” according to IEC60947-5-1 Annex L. This is true for the basic 3RH relay with or without an additional auxiliary contact block.