Ace NEBOSH 2026: Boost Your Safety Savvy with This Dynamic Practice Test!

Highly flammable liquids are characterized by their ability to ignite easily and often do so at low temperatures. The statement that they can ignite without any external energy input highlights a critical safety concern; such liquids can catch fire from a spark or even from heat sources, which can include ambient temperatures or static electricity. This volatility makes proper handling and storage essential in preventing fires and ensuring safety.

In comparison, the other statements do not accurately depict the properties of highly flammable liquids. The notion that they have flashpoints above 32°C contradicts the definition since highly flammable liquids typically have flashpoints below this temperature. The idea that they are safe to use at any temperature is misleading because their safety is contingent on being kept below their flashpoint. Lastly, suggesting that they must always be stored in open containers is not only impractical but also dangerous, as it increases the risk of evaporation and potential ignition from external sources. Proper storage requires sealed containers designed to minimize risks related to flammability.