Except of course SN isn't "controlled", nor is it dangerous (sodium azide would be due to its explosive properties). I live where OP lives, it's a member state since 2004 and I know for a fact that you could buy a truckload without any permissions or IDs, then resell, gift, snort it or whatever.
Perhaps it's due to difficulties in obtaining it in some places, but you guys are treating it as the next N whilst forgetting what it ultimately is: E250, a food additive. Today someone implied there's jail time for merely pointing someone to sources - really embarrassing.
And don't even get me stared about "poison", it's a notoriously ambiguous term. The dose makes the poison. If you can't get in trouble for sending someone lethal dose of table salt, then you sure as hell won't for sending different kind of it.