What substance should not be placed near an ignition source because it is explosive?

The selection of propane as the substance that should not be placed near an ignition source is accurate due to its highly flammable and explosive nature. Propane is a colorless and odorless gas when stored, but it can easily ignite and produce a powerful explosion when it comes into contact with an open flame or spark, especially in confined spaces. This is critical to understand in safety practices, as mishandling propane can lead to severe accidents, including fires or explosions that pose significant risks to personal safety and property.

While other substances listed, such as gasoline, aerosol cans, and alcohol, also pose flammability risks, propane is known for its ability to create explosive mixtures when combined with air. This makes proper handling, storage, and awareness of the surrounding environment vital when dealing with propane to prevent dangerous situations. Awareness of these characteristics contributes to effective safety practices in environments where flammable substances are present.