Emulsifiable concentrates (EC) continue to be the preferred formulation type as judged by the number of new formulations registered each year. The key component of an EC formulation is a solvent capable of dissolving the active ingredient. This paper examines common types of hydrocarbon and oxygenated solvents registered for agricultural chemical use and identifies some critical physical properties that can be used to guide the formulator in his solvent selection. Properties such as Kauri Butanol (KB) Value (ASTM D1133), Aniline Point (ASTM D611), and Hildebrand or Hansen Solubility Parameter are generally recognized, direct measures of solvency. If applied properly, these properties can directionally give valuable starting information on solvency. Each of these test methods will be described together with how it relates to solvency of a fluid. In addition, the relevance to the formulator of ECs will be demonstrated by correlation of the results of these tests with laboratory-determined solubility of several generic pesticides.