How many classes do water-reactive materials have in relation to their hazard?

Water-reactive materials are categorized into three distinct classes based on their hazards. This classification is essential for understanding the different types of reactions these materials can have when they come in contact with water.

The first class includes substances that react violently with water, producing heat and releasing toxic gases. These materials can cause significant safety risks if they come into contact with moisture or are exposed to water.

The second class comprises substances that react with water but produce less intense reactions, which may still generate gas or heat, posing a risk if accumulated in a confined space or released in large quantities.

Lastly, the third class encompasses materials that react mildly with water, producing non-hazardous products or minimal heat. While less hazardous than the first two classes, these materials still require careful handling to prevent unintended reactions.

Understanding these classifications is critical for laboratory safety and proper emergency response planning when dealing with flammable and reactive materials.