Small Refiner Relief Act of 2012 - Defines "small business refiner" for purposes of administering any law under the Environmental Protection Agency's (EPA) jurisdiction to mean, with respect to any taxable year, a refiner of crude oil: (1) with respect to which not more than 1,500 individuals are engaged in the business's refinery operations on any day during such year, and (2) the average daily domestic refinery run or average retained production of which for all facilities of the taxpayer during any calendar year did not exceed 205,000 barrels.