Which class of fire extinguisher is typically used for solvent fires in the chemistry lab?

Get ready for the Chemistry Lab Safety Test. Prepare with flashcards and multiple-choice questions, complete with hints and explanations. Master essential safety protocols for laboratory experiments!

Solvent fires involve flammable liquids, so the extinguisher chosen must effectively handle liquids and be safe around any electrical equipment commonly found in a chemistry lab. A multipurpose dry chemical extinguisher is particularly well-suited because the dry chemical powder blankets the liquid, coating the surface and interrupting the chemical reactions occurring at the flame. This stops the fuel–air and radical-chain reactions that keep the fire going, making it effective on a wide range of hazards, including flammable liquids and electrical equipment.

Water extinguishers are not appropriate for solvent fires because water can spread the flammable liquid, potentially spreading the fire or causing splashes. Foam extinguishers can handle some liquid fires but may leave residues that complicate experiments and cleanup, and they aren’t as versatile for the variety of hazards that can be present in a lab. Wet chemical extinguishers are designed for cooking fats and oils and aren’t suitable for typical laboratory solvents. Therefore, a dry chemical extinguisher that covers flammable liquids (and other common lab hazards) is the best choice for solvent fires in the chemistry lab.