Which property of creosote contributes to its effectiveness against organisms?

Insolubility in water is a significant property of creosote that contributes to its effectiveness against organisms such as fungi, insects, and bacteria. This characteristic allows creosote to resist leaching when exposed to moisture, which is crucial for its use in wood preservation. When wood treated with creosote is placed outdoors or in damp environments, the creosote remains in the wood, creating a long-lasting protective barrier. This prolonged presence in the wood means that it can continuously protect against decay and insect infestations, thereby extending the lifespan of the treated wood.

The other properties mentioned do not provide the same level of effectiveness in preventing biological degradation. For instance, low density does not contribute to its protective qualities, while high solubility would allow the creosote to wash away in water, reducing its protective impact. Moreover, a non-staining formulation is not a relevant factor in the effectiveness of creosote as a preservative against organisms, since it primarily focuses on cosmetic attributes rather than functional efficacy.