This one will forever stick in my (small) mind:
When going thru the classroom portion of 'basic demolitions', the students were provided with a 'master demolitions table'.
The table had the name(s) (common and chemical formula) of numerous types of explosive materials, where you could find them (i.e. 'liquid, used in pre-199x 5" naval HE") in case you needed to construct an IED, REF (relative explosive force - so you knew how powerful the stuff was when running the calculations for different types of demolition work), and 'special notes'. The 'special notes' area usually had 'notes' along the lines of "Do not confuse with xxxxxxxx appearance and odor are highly similar" or "causes severe dermatitis handle with extreme caution" or "highly unstable at temperatures exceeding xxxx", etc.
About 2/3 of the way down the table, in the 'special notes' column for one type of material, it read...
"Highly toxic - do not eat"
...now one of the certain things in the military is if there is a specific rule/regulation/warning/guidline/addendum to SOP its creation is almost always the result of someone's (very bad) experience.
I have always wondered the circumstances that caused someone to add that 'special note'.

Mike/wulfie