Pyrophoric materials are defined as?

Pyrophoric materials are defined as?

• A. A liquid or solid that when in contact with air and without an external ignition source can be ignited within 5 minutes.
• B. A liquid or solid that requires an external flame to ignite.
• C. A liquid or solid that cannot ignite in air.
• D. A substance that only emits heat but does not ignite.

Answer: (A)

Pyrophoric materials ignite automatically when they come into contact with air, without needing an external ignition source. They can catch fire within a short time after exposure to air, often within seconds to minutes. That’s the behavior described by the option stating ignition can occur in a short time after air contact. The other descriptions—needing a flame to ignite, not igniting in air, or only emitting heat without ignition—do not match this spontaneous-ignition behavior.

Pyrophoric materials ignite automatically when they come into contact with air, without needing an external ignition source. They can catch fire within a short time after exposure to air, often within seconds to minutes. That’s the behavior described by the option stating ignition can occur in a short time after air contact. The other descriptions—needing a flame to ignite, not igniting in air, or only emitting heat without ignition—do not match this spontaneous-ignition behavior.