...More to the point....I had the responsibility of disposing of one cube of sodium cyanide ... ....Several years (and many officials)later I still had the cyanide.
Passing the buck is a well known pastime for officialdom. Had any
one of those people asked a chemist, or a chemistry teacher, they
would all have suggested that he dissolve the cyanide in water, then
slowly added a solution of (cheap) ferrous sulphate until no further
precipitate could be observed. The ferrous salt is very insoluble, and
could have been safely mixed with sawdust or even dry dirt, and left
in the sun until the water had evaporated, then the remains could have
been safely scattered at the local rubbish tip, or even scattered on
waste ground. Yes, it would eventually get broken down - into iron
oxide and hydroxide, carbon dioxide and ammonia. – Cheers now, John
Burgess; @John_Burgess2 of Mapua Nelson NZ where there are
daffodils and new born lambs