cabon cutting blade, ******* genius, which marketing dept. came up with that one? oh wait, let me guess, they are blue? still, you makes your choice in life, if you have 8 quid to spend then it would be any worse than a good quality high TPI blade.
Eclipse 32tpi bi metal blade in any hack saw frame will do it happily. I guide is a good idea if you can (especially if you didn't spend the first half you life in a fab shop), but if you haven't got one, drill a hole through a chunk of wood and use the side as a guide. As you are cutting a thin wall tube it's worth while cutting in stages and rotating the bar so you are always cutting more material than if you cut through the middle, you want to keep about 6 teeth in the material at any one time and as you cross the middle this will be more like 3 or 4 which will make a for a difficult time keeping it straight as the saw will struggle and jump a bit and may also result in tear out (not a promise though, it depends on the layup). A pack with an 18,24 and 32 in is 8 quid on amazon or any good tool shop should stock it for a few quid.
on ali bars I use a pipe cutter, but that isn't an option thanks the the epoxy encapsulation.
but yes, don't breath the dust, worse than fibre glass and unless we turn you upside down and shake, doesn't come out your lungs.