What is a 'hot spot' and why is it dangerous in reactive storage?

• A. A region with high humidity that accelerates corrosion.
• B. A region of low oxygen that inhibits reactions.
• C. A localized high-temperature area that can trigger accelerated reaction and runaway.
• D. A vent that reduces pressure safely.

Answer: (C)

A hot spot is a localized high-temperature area inside a storage system containing reactive materials. This matters because many reactive substances release heat when they react or decompose, and reaction rates climb rapidly as temperature rises. If that heat isn’t removed quickly enough, the local temperature increases further, creating a loop where heat production and temperature boost each other—thermal runaway. The result can be an uncontrolled, fast release of energy, leading to high pressure, gas formation, venting, or even an explosion, especially in crowded or poorly cooled storage. The other options describe conditions that aren’t hot spots: humidity-driven corrosion, low-oxygen inhibition, or a venting device, none of which capture the danger of a self-localized, heat-fueling reaction.