Chemistry - What makes pentane, hexane, heptane, and octane dangerous, while butane and nonane aren't?

Solution 1:


Pentane, hexane, heptane, and octane are labelled with the ‘environment’ hazard pictogram (GHS09) since they are considered toxic or very toxic to aquatic life with long-lasting effects (H411 or H410) because of their toxicity to the water flea Daphnia magna in standardized tests.

Nevertheless, nonane is not completely harmless; it still may cause long-lasting harmful effects to aquatic life (H413). However, a pictogram is not required for this hazard category.

According to a comparative study, the toxicity of these substances is mainly determined by their solubility in water and their organism–water partition coefficient.

Solution 2:

Butane is a gas at STP, so it would not accumulate in one location.