Currently none of the standards require independent or 3rd party testing.  Much of this responsibility is given to the AHJ who is supposed to ensure all codes are followed. The reality is few AHJ completely understand the standards and are easily persuaded by the installer that everything has been done correctly. Increasingly the role of ensuring the building is up to spec has been taken on by commissioning agents. Their job is to ensure that the entire building is up to spec and that includes the suppression system. The commissioning agent is hired by the owner to ensure the owner is getting what they paid for, which includes compliance with all building and NFPA codes.

We often get questions from AHJ or commissioning agents who are concerned about how the enclosure test was performed, and there is good reason for this. Half the enclosure integrity tests done in Europe and 60% of those performed in the US do NOT include a peak pressure evaluation. Peak pressure evaluation has always been required by ISO and has been required by NFPA since the 2008 version of NFPA 2001.  This does not take into account enclosures where the integrity test was never performed in the first place, so it's safe to say that a lot less than 50% of all enclosures are in compliance. The bad news when it comes to Peak Pressure is that many enclosures that need vents don't have them, and in many cases they are installed backwards, do not open at the correct pressure, or have the venting path blocked. Any of these issues can spell disaster during a discharge. Thankfully this is being recognized by the industry and they have voluntarily performed experiments to see what venting requirements really are. All of this information is now in our FanTestic Integrity software.