NFPA and ISO do not certify any equipment or software directly. They are simply a standards writing body who takes input from the industry.  In the case of hold time calculation and peak pressure evaluation the input from the industry was primarily from Colin Genge the CEO of Retrotec who wrote the original NFPA Enclosure Integrity Procedure for NFPA in 1984 and has been the only force in making changes to the Standards ever since.  As a result, Retrotec training certification is accepted across all equipment manufacturers, end users in over 60 countries.

Colin Genge is used as a resource by Siemens, Tyco, Kidde, Ansul, Chemetron, Janus, Fike and 3M. If there is a question about enclosure hold time or peak pressure, he is the one who answers it.