Fire extinguisher changes

[Simon Hadfield]

In the last few days it has become apparent that the Fire Extinguisher regulations have shuffled sideways a tad. It appears that the MSA regulations have been different to those of the FIA and starting this January the regulations are merging.
The practical issue is that the FIA bottles appear to be substantially larger for the "standard, propellant and extinguishant" type that I suspect most of us use.
So, several points;
Did the MSA tell us this was coming? Was it in one of the bulletins we are emailed and I missed it?
Have the MSA cars had more fires than other ASNs cars?
Have those fires been more serious?
Has anyone actually tried to understand the FIA Appendix J section for fire extinguishers? Having not been part of Bletchley Park I struggle to make sense of it, why cannot someone put in simple language "a Formula Ford needs this, and three box saloon needs this, an open two seater sports car needs this....instead of the reams and reams of obscure dimensions. Does anyone here know the internal volume of their car? Really?
Whatever, was anyone from Historic racing consulted about this? The way things are going we will need to tow a trailer behind our race cars with the fire extinguisher on it...
We are asked to put the fire extinguisher within the main structure of the chassis - easy in a Mustang, not so easy in a 1971 Formula Ford, especially if you intend to sit in it to drive it too.
Nationally, as I understand it the "MSA" extinguishers now in use will be re-filled and accepted until 2020 (I think, if I understand the information now available) but will not be acceptable for International use as of now.
If I have this wrong I would gladly be corrected. I would also point out that this is not specifically an Historic issue, but has come from the offices of real racing, we just have to make the best of it.
Also I do realise that separate extinguishant and propellant systems are available, that they are much smaller, but the prices make your eyes bleed.