My understanding is that those tiles are made of cellulose fibre. If so, then then take them to a municipal compost site, where they can be shredded and added to the mix of spent xmas trees, leaves, yard waste, etc for decomposition and resale as compost.
Granted there may be some fire retardant mixed in whith the cellulose fibre (and other stuff like paint, glue, etc). Not sure how much of a problem this would be -- I suspect the retardant is some sort of mineral, which, when the tile is added to a municipal compost mix, would be sufficiently diffused that it should pose a problem to end users of the compost.
Alternatively, if they are the typical commercial tiles that hang from metal supports (i.e. they aren't the type that are stapled) and they are in good condition, there may be a "reStore"-type hardware place in Mississauga that would accept them in the hopes of someone else needing them.
Good luck, Eric.