When reporting compliance parameters to EPA on the batch reports we are asked to report to a greater degree of precision than the regulations indicate for the standard. An example would be that the per-gallon oxygen content standard is supposed to be 2.0

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You would be in compliance for the example described above. In order to determine compliance EPA will round all values to the appropriate decimal place for the applicable standard. If the digit immediately to the right of the last appropriate decimal place for the standard is 5 to 9 the digit at that decimal place will be rounded up (1.95 will be rounded to 2.0.) If the digit immediately to the right of the appropriate decimal place for the standard is 0 to 4 the value should be truncated (rounded down) at the appropriate decimal place (1.94 will be rounded to 1.9.). (5/9/95)

This question and answer was originally posted at Consolidated List of Reformulated Gasoline and Anti-Dumping Questions and Answers: July 1, 1994 through November 10, 1997 (PDF)(333 pp, 18.17 MB, EPA420-R-03-009, July 2003, About PDF)