Hydrogen peroxide decomposes giving off oxygen and water. To slow this down, people put it in the fridge. Relative to room temp, a fridge is about 20 deg C cooler. read more
Hydrogen peroxide is perfectly at home in an unrefrigerated medicine cabinet on one condition; it's kept in the dark. Light will break down the highly unstable H2O2 molecules into oxygen gas; the fizzing effect is from the release of oxygen. Over time what's left in the bottle will be nothing but water. High strength solutions are more unstable. read more
Hydrogen peroxide is perfectly at home in an unrefrigerated medicine cabinet on one condition; it's kept in the dark. Light will break down the highly unstable H2O2 molecules into oxygen gas; the fizzing effect is from the release of oxygen. read more