What type of solvents are commonly used in emulsifiable concentrates (EC) formulations?

• A. Water-based solvents
• B. Petroleum-based solvents
• C. Ethanol-based solvents
• D. Alcohol-free solvents

Answer: (B)

Emulsifiable concentrates are meant to be mixed with water to form a stable emulsion, so the solvent must be oil-like and immiscible with water. Petroleum-based solvents provide that non-polar oil phase, dissolve lipophilic pesticides effectively, and thinly disperse as droplets when the emulsifier is added and the mixture is sprayed. Water-based or alcohol-based solvents would mix with water and fail to form the necessary oil-in-water emulsion, making petroleum-based solvents the standard choice for EC formulations.