Stephen Dawson wrote:

6242BH and 6243BH in white, this is an LSF cable, low smoke and fume, and a
lot more expensive than standard PVC

These are new cable types, mentioned briefly in the current issue of
'Wiring Matters' (IEE publication). They're 90 deg C. rated
thermosetting-insulation types, to BS 7211, and will have higher current
ratings than normal (624xY) twin/triple-&-CPC cables. I've not seen any
current rating data yet though.

'Wiring Matters' mentions their use as appropriate for situations where
it's unavoidable that a cable is completely surrounded in thermal
insulation. There's a forthcoming IEE publication to be called "the
electrician's guide to the building regulations" which will include some
standardised circuit designs for this situation.

Is there a plan, I wonder, that in future flat PVC cables (BS 6004) will
only be available in grey, with white used for this new type?

--
Andy