Artificial Intelligence Notice: ISA prohibits the entry of any ISA intellectual property (“ISA IP”), including standards, publications, training or other materials into any form of Artificial Intelligence (AI) tools, such as ChatGPT. Additionally, creating derivatives of ISA IP using AI is also prohibited without express written permission from ISA’s CEO. In the case of such use, ISA will suspend a licensee’s access to ISA IP, and further legal action will be considered. Please review ISA's policies for Use of AI Tools, Intellectual Property and Terms and Conditions for further information.
Important Notice: Print books are temporarily unavailable. As of 12 August 2025, print books are no longer available for purchase on isa.org, but beginning 1 January 2026, they will be available for purchase through our publishing partner, Wiley. Kindle and ePub formats are still available via the links on each book's product page on isa.org. Learn More.
The ISA91 Committee, Criticality Ranking for Instrumentation, was merged in late 2007 as a working group into ISA84, Electrical/Electronic/Programmable Electronic System (E/E/PES) for Use in Process Safety Applications. For information about the former committee or about ISA84, please contact ISA Standards.