@ Paul P - UPS have their own cargo planes, I think. Maybe others do too.
If u buy from overseas, definitely best to check the carrier at present - some independent ones have 'hazardous goods' licences so can ship using own transport from start to finish. Generally, only large businesses will be using these as the price for 'contract' customers is reasonable, but not for private ones. Just because someone in the U.K. is an internet business doesn't mean they have sorted this out right now as we were given no notice.
Sorry, don't know your regs - someone else may?
Some larger U.K. sellers, such as Ormond Jayne, have already made arrangements.
Sorry not to be more helpful - situation is still developing.