Ketchup
Naturally, ketchup is acidic and is also hostile to microorganisms. Due to this microorganisms can’t grow on ketchup. This makes the likelihoods of ketchup turning bad very negligible. Many people followed this and reported that it has a nicer flavour when stored at room temperature. So to enjoy the fresh taste of ketchup you don’t have to store it at room temperature.
But if your neighborhood is hot, then you might have to consider storing your ketchup bottle in the refrigerator after opening. Moreover, if your use is less then the fridge will help to increase its life.