The list of banned items is extensive, but what happens if you have a genuine need to carry something banned? The carry-on specific items is easy enough, you just check it (e.g. sharp objects), but some items (e.g. chlorine, some aerosols, gas torches or many other such objects) which might genuinely be needed for work, are banned in either form.
Is there a process to getting an exemption to carry banned items, and if so, what/where is it?