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What is the operational tolerance for denaturant in ethanol to meet the definition of Renewable Fuel? The RFS2 definition calls for a maximum of 2% denaturant. What if the lab results come back higher or lower than 2%? For example, what if the lab results

The definition of renewable fuel in 80.1401 specifies that the maximum amount of denaturant in ethanol that can be treated as renewable fuel is 2 volume percent. If lab results indicate that the concentration of denaturant is higher than 2%, then any denaturant in excess of 2% cannot be treated as renewable fuel, and RINs cannot be generated to represent it.

However, conventional rules of rounding apply since the regulations specify the limit as 2%, not 2.0% or 2.00%. Thus, for example, if the denaturant concentration was tested and found to be 2.44%, this would be deemed equivalent to 2% and RINs could be generated for the entire volume. However, if the denaturant concentration was tested and found to be 2.66%, this would be deemed equivalent to 3% and RINs could only be generated to represent 99% of the volume of denatured ethanol.