During product control, the foam used for polar solvents is:

• A. Alcohol resistant concentrate.
• B. Regular protein foam.
• C. Protein foam with alcohol additive.
• D. Aqueous film-forming foam.

Answer: (A)

When dealing polar solvents, you need foam that can withstand the solvent’s alcohol content. Alcohol-resistant concentrate foam is designed for this scenario; its chemistry resists breaking down in the presence of alcohols, so it maintains the foam film and provides effective coverage and cooling on spills of polar solvents.

Regular protein foam isn’t resistant to alcohols, so its performance deteriorates with polar solvent spills. Adding alcohol to a protein formulation isn’t a reliable fix and isn’t how these foams are typically specified. Aqueous film-forming foam is excellent for hydrocarbons but isn’t alcohol-resistant, so it can break down when polar solvents are involved. Therefore, the best choice for polar solvents is the alcohol-resistant concentrate foam.