What is a material that is reactive to air known as?

A material that is reactive to air is characterized as pyrophoric. Pyrophoric substances can ignite spontaneously upon exposure to oxygen in the air, making them highly hazardous. This unique property requires special handling and storage conditions to prevent dangerous reactions, such as fires or explosions.

In terms of characteristics, while flammable materials do ignite under specific conditions, they require an external ignition source, unlike pyrophoric materials. An oxidizer refers to a substance that provides oxygen to support combustion but does not necessarily react spontaneously with air. Corrosive materials can damage living tissue or substrates upon contact but do not define reactivity with air as a pyrophoric material does. Understanding the properties of these materials is crucial for safety in hazardous situations.