Danger 1824

Danger! 1824!

Meaning... these vials of liquid will harm ashtrays and thumbs on people with very long fingers? And, in tiny, tiny little text on the left hand side is the word 'corrosive'. I guess it means I shouldn't try and damage the pipe because I will get hurt, but it doesn't look like I'd be too successful using my hands (or an ashtray).

(found beside the rear service entrance of a building near Simcoe and Adelaide)