Just checked it out and BP just stands for British Pharmacopoeiaust which is simply a guarantee that it is high grade. Guess I'm good to go on that one. So, where do I lay my hands on the other core ingredients if I want to start mixing my own? Fairly sure my chemist won't be selling liquid nicotine. And what is it with adding a touch of 'distilled' water to reduce the viscosity? After spending half a lifetime sucking on smoke surely my system can tolerate a splash of good old fashion tap water?
The BP seal is what you want, it's essentially the same as our USP, which is what we look for here in the States. Nicotine you will probably have to source online. I use 100mg but I'm not sure you can get that where you are, you might be capped at 72mg/ml I think? Anyway, it's generally advised to get the strongest nic you can, as it's more cost-effective that way and takes up less space in the freezer. VG, you can get online or at the chemist, and if they don't have PG, you can usually find it (over here anyway) at farm/feed supply stores, since it's added to...I think it's goat feed, to keep them from getting some reproductive disorder or something like that. Many people buy flavorings direct from the manufacturers, or else from a specialty DIY supplier online. Popular brands are FlavourArt, The Flavor Apprentice/Perfumer's Apprentice, Hangsen, Inawera, and Capella's.
Tap water has junk in it like chlorine and fluoride (at least here it does, sometimes), and heavy minerals and other stuff you might not necessarily want to be vaping if you can avoid it. Every grocery store in America has distilled water by the gallon for like a dollar. Presumably they have it where you are, too?