How does avoiding ignition sources contribute to process safety?

• A. Reducing ignition sources lowers the probability of ignition in flammable atmospheres, decreasing the chance of fires/explosions.
• B. Ignition sources have no impact on the likelihood of fires.
• C. Avoiding ignition sources only affects electrical equipment hygiene.
• D. Ignition sources are only relevant during startup.

Answer: (C)

Reducing ignition sources lowers the probability that a flammable atmosphere will ignite. In process safety, fires and explosions occur when a source of energy (a flame, spark, hot surface, static discharge, or energized equipment) provides enough energy to reach the mixture’s ignition energy. If you minimize or eliminate these sources—through proper electrical design (intrinsic safety, proper enclosures), bonding and grounding to prevent static sparks, rigorous hot-work controls, eliminating open flames, and keeping equipment clean and cool—you greatly decrease the chance that a flammable atmosphere will ignite, thus reducing the risk of fires and explosions. The other ideas are too narrow or misleading: ignition sources do matter for more than just equipment hygiene, and their presence isn’t limited to startup; they can cause ignition at any time, so focusing solely on startup or on hygiene misses the broader safety impact.