(a) Compliance with the sulfur standards of this subpart O shall be determined based on the sulfur level, measured or otherwise determined as applicable using the methodologies specified in §§80.47, 80.1611, and 80.1630. Any evidence or information, including the exclusive use of such evidence or information, may be used to establish the sulfur level of gasoline, ethanol denaturant, or oxygenate if the evidence or information is relevant to whether the sulfur level would have been in compliance with the standards if the appropriate sampling and testing methodology or other sulfur determination methodology as applicable had been correctly performed. Such evidence may be obtained from any source or location and may include, but is not limited to, test results using methods other than those specified in §§80.47 and 80.1630, business records, and commercial documents.

(b) Determinations of compliance with the requirements of this subpart other than the sulfur standards, and determinations of liability for any violation of this subpart, may be based on information obtained from any source or location. Such information may include, but is not limited to, business records and commercial documents.