Which term refers to a substance that can ignite upon contact with air?

The term that refers to a substance that can ignite upon contact with air is "pyrophoric." Pyrophoric materials are highly reactive and spontaneously ignite in the presence of oxygen or moisture, typically at ambient temperatures. This characteristic makes them particularly hazardous and requires special handling and storage procedures to prevent accidental ignition.

Catalysts are substances that accelerate chemical reactions but do not themselves undergo permanent chemical change. Inhibitors are chemicals that slow down or prevent reactions. Oxidation potential refers to a measure of a substance's ability to undergo oxidation, which is related to its reactivity; however, it does not specifically describe a substance’s capacity to ignite on contact with air.

Understanding the properties of pyrophoric materials is crucial for hazardous materials technicians, as it directly influences safety protocols during handling and response operations.