Which solution can be effectively used to extinguish a small paper fire?

The most effective choice for extinguishing a small paper fire is carbon dioxide. Carbon dioxide is an effective fire suppressant because it works by displacing oxygen, which is essential for combustion. When the concentration of carbon dioxide in the vicinity of the fire increases, the oxygen levels decrease, making it difficult for the fire to sustain itself. This method is particularly safe for use on flammable materials like paper, as it will not cause additional damage or react dangerously with the burning material.

Using water on a paper fire can be effective as well; however, it is not always the best option because if the fire has any electrical components or if it is part of a larger fire, water could spread the flames or create hazards. Dilute hydrochloric acid and alcohol should never be used to extinguish a fire. Alcohol is flammable and would only exacerbate the fire, while dilute HCl could produce harmful fumes and also facilitate the fire's progression rather than extinguishing it.