The process of controlling fumes or vapors that are given off by flammable liquids is called?

• A. Eliminating ignition sources
• B. Vapor suppression
• C. Vapor dispersion
• D. Positive pressure ventilation

Answer: (B)

Controlling fumes from flammable liquids means reducing the amount of vapor released at the source. That direct action is vapor suppression. By applying barriers or suppressants—such as foam blankets, surface coverings, or absorbent materials—you slow or limit evaporation, lowering vapor concentrations near the spill and reducing the risk of ignition and inhalation.

Eliminating ignition sources helps prevent ignition if vapors are present, but it doesn’t stop the liquid from evaporating. Vapor dispersion describes how vapors move through the air once released, not how they are kept from forming. Positive pressure ventilation helps dilute vapors in the environment, but it doesn’t suppress the vapor that’s being produced from the liquid itself. Vapor suppression specifically targets and reduces the release of vapors at the source, which is why it’s the best answer.