There's an irony that jewellers can easily buy Potassium cyanide through their suppliers (used for stripping - cleaning, castings and plating) with no paperwork and more importantly no audit trail of the disposal, and as photographers we have issues with far less hazardous substances.
Should add that about 25 years ago my factory unit had a visit from the London Met Drug Squad looking for an illegal narcotics factory, that was because equipment suppliers had passed on what I was buying. Our use was legit so no problems.
It's not just the DEA or equivalent that want forms filled it's local authorities and police as well in some cases. It can be non chemists who make arbitary and nonsensical decisions as to what is/isn't safe.