Incorporated by Reference Accuracy

This responds to your June 29, 2006 letter requesting clarification on § 171.7 Reference material, materials incorporated by reference into the Hazardous Materials Regulations (HMR; 49 CFR 171-180). Specifically, you ask whether the "Association of American Railroads, AAR Manual of Standards and Recommended Practices, Section C-Part III, Specification for Tank Cars, Specification M-1002, December 2000 edition" referenced in § 171.7 is the most current version.

The AAR standard you reference was updated as of December 1, 2003. However, the updated standard has not been incorporated by reference into the HMR. Therefore, for purposes of the HMR, the 2000 edition referenced in § 171.7 must be used.