Intrinsic Safe (IS) is defined as

Intrinsic Safe (IS) is defined as

• A. Is Incapable Of Causing Ignition Of A Prescribed Gas
• B. Can Ignite A Gas If Near A Spark
• C. Provides Flameproof Enclosure
• D. Protects Against All Electrical Faults

Answer: (A)

Intrinsic safety centers on keeping the energy available in a circuit so low that it cannot ignite the hazardous gas present. By designing circuits to limit voltage, current, and stored energy—and by using barriers or energy-limiting components—the equipment ensures that even in fault conditions the energy never reaches the level needed to ignite the gas. That is why the correct description is that intrinsic safety is incapable of causing ignition of a prescribed gas. This approach is different from flameproofing, which relies on containing a flame if ignition occurs inside the equipment, or from broad fault protection—intrinsic safety specifically targets preventing ignition by design, not just guarding against every possible fault.

Intrinsic safety centers on keeping the energy available in a circuit so low that it cannot ignite the hazardous gas present. By designing circuits to limit voltage, current, and stored energy—and by using barriers or energy-limiting components—the equipment ensures that even in fault conditions the energy never reaches the level needed to ignite the gas. That is why the correct description is that intrinsic safety is incapable of causing ignition of a prescribed gas.

This approach is different from flameproofing, which relies on containing a flame if ignition occurs inside the equipment, or from broad fault protection—intrinsic safety specifically targets preventing ignition by design, not just guarding against every possible fault.