I received an e-mail inquiring about a product being “listed” or not, which made me stop and think about how far we have come in the past 10 years regarding safety systems and their “type” of certification.  The term “listed” means equipment or materials included in a list published by an organization ...

 Have you had a chance to catch Bill Goble’s Hydrocarbon Processing (October 2007 issue) editorial titled “Still not using a safety PLC?” Essentially Bill addresses the question of whether you can use conventional equipment (PLC or DCS) in compliance to ISA 84.00.01-2004 (IEC 61511 Mod.)? I think he did a nice job ...