What is the most appropriate initial response to a significant acetone spill?

The most appropriate initial response to a significant acetone spill is to evacuate and ventilate the area. Acetone is a highly flammable and volatile organic compound that can pose serious health risks due to its fumes, which are harmful if inhaled. By evacuating the area, you are ensuring that individuals are removed from potential exposure to these harmful vapors. Ventilating the space allows fresh air to dilute and disperse the acetone vapors, reducing the risk of explosive concentrations forming and ensuring that responders are working in a safer environment.

Neutralizing acetone with water is not recommended because acetone is not reactive with water in a way that would render it safe; instead, it can create a hazardous situation where the mixture may spread further. Containing the spill with absorbent material, while important in a later response stage, should only be done once it is safe to approach and only after evacuation and ventilation efforts are established. Using a fire extinguisher would be inappropriate as an initial response; while acetone is flammable, the best course of action is to avoid ignition sources and focus on protecting people first.