: Before you throw away the containers look for any "best before
: .....". I´ve had a couple of old containers with both resin and
: hardener left. I opened the hardener container and was nearly knocked out
: by the intense vapour. Talk about bad breath!!! This smell was corrosive
: and lasted for a long time. All left containers was disposed of as
: dangerous garbage for destruction at the environmental station along with
: the chemical certificate.
: Keep your smaller containers as cold as possible and in the dark.

I took a whiff of mine, which had been opened less than 2 months earlier, and the ammonia smell floored me. It has been kept in the dark and still works fine.