saltwater makes milk jug suck in?
 

sometimes ill leave some saltwater in a plastic milk jug, and this has happ, twice now, after a month or two the milk jug will suck in on itself and develop a leak, any of you chem guys know what goes on or has anyone seen this? not doing it anymore, but im curious as to what reaction causes this...............

There are gases inside the jug that creates pressure. As the water ages in a sealed container the gas may get used up in reactions, this lowers the pressure inside the jug collapsing the walls. Same thing if the water was put in side the jug warm and then cooled. Warm water has more pressure and as it cools the pressure reduces collapsing the jug. You usually only see things things with very thin wall jugs.

ah, it is put in there at temp, cool ty