Code of Federal Regulations Title 40. Protection of Environment § 40.1090.1337 Demonstrating homogeneity

(a) Certification test results corresponding to manual sampling as specified in § 1090.1335(b) are valid only if collected samples meet the homogeneity specifications in this section, except that the homogeneity testing requirement does not apply in the following cases:

(c) Use spot sampling as specified in § 1090.1335(b)(2) for homogeneity testing. Tap sampling is acceptable if spot sampling is impractical for a given facility.

(d) Demonstrate homogeneity for gasoline using two of the procedures specified in this paragraph (d) with each sample. For summer gasoline, the homogeneity demonstration must include RVP measurement.

(e) For testing to meet the diesel fuel standards in subpart D of this part, demonstrate homogeneity using one of the procedures specified in paragraph (d)(1) or (2) of this section.

(f) Consider the batch to be homogeneous for a given parameter if the measured values for all tested samples vary by less than the published reproducibility of the test method multiplied by 0.75 (R x 0.75). If reproducibility is a function of measured values, calculate reproducibility using the average value of the measured parameter representing all tested samples. Calculate using all meaningful significant figures as specified for the test method, even if § 1090.1350(c) describes a different precision. For cases that do not require a homogeneity demonstration under paragraph (a) of this section, the lack of homogeneity demonstration does not prevent a quantity of fuel, fuel additive, or regulated blendstock from being considered a batch for demonstrating compliance with the requirements of this part.