> If it happens in a minute at 260 C, it will still happen at 200 C, just slower.
I don't think that's particularly accurate unless you're considering the action of individual atoms. e.g. Water is considered to boil at 100°C but there will be some water evaporating at lower temperatures but this is a different process that only occurs at the surface. I don't think it's accurate to say that water is "slowly boiling" at low temperatures unless you're reducing atmospheric pressure.
The result is the same though. The water leaves the container and enters the atmosphere as vapor. You can call the former "decomposition", and the latter "leaching", but you are eating the degradation products either way.
I don't think that's particularly accurate unless you're considering the action of individual atoms. e.g. Water is considered to boil at 100°C but there will be some water evaporating at lower temperatures but this is a different process that only occurs at the surface. I don't think it's accurate to say that water is "slowly boiling" at low temperatures unless you're reducing atmospheric pressure.