Did you know that in the wrong circumstance a 2-BTP extinguisher will feed a fire rather than extinguish it? It’s a phenomenon called subinerting. One manufacturer blew up an FAA lab pretty badly while testing 2-BTP. Here’s a report on the earth-shattering kaboom. I only got to see he wreckage a few weeks later. https://www.nist.gov/publications/chemical-kinetic-mechanism...
Permanently installed Halon firex systems in commercial aircraft will not be phased out until 2040. I have been working, as a part of larger team, to certify a non-halon based firex in cargo and engine compartments for many many years now. It's been slow going. All commercial aircraft from all manufacturers still use Halon for their permanently installed firex and will continue to do so for the near future. We have put non-halon systems into some military aircraft that go thru a commercial certification, for example the KC46 tanker, but there are some good reasons it would not be the best choice for an actual commercial aircraft. https://www.af.mil/News/Article-Display/Article/740629/kc-46...
If anyone actually gave a rip about ozone depletion, they would ground the F-16 fighter. The F-16 inerts it’s fuel tank ullage space with Halon. Every F-16 flight is a direct injection of pure Halon straight into the stratosphere. Mainline that stuff, feels so good. https://arc.aiaa.org/doi/abs/10.2514/6.1981-1638