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What are PHMSA Interpretation Letters?

What are PHMSA Interpretation Letters?

Sometimes the Hazardous Materials Regulations (HMR; 49 CFR Parts 100-185) of the PHMSA/USDOT are not enough.  If you find yourself in a situation where you cannot find an answer to your HazMat transportation question you have three options:

  1. Apply your interpretation of the regulation to your situation and hope for the best.
  2. Contact PHMSA’s Hazardous Materials Information Center (HMIC).  They will answer your questions after reviewing the regulations and likely reviewing their database of interpretation letters. Hazardous Materials Information Center
  3. Contact me and I’ll answer your question after reviewing both the HMR and any applicable Letters of Interpretation in the PHMSA database.

Notice the similarity in the responses to actions 2 & 3?  I don’t recommend #1.  So, what are the PHMSA’s Letters of Interpretation?  Basically, they are PHMSA’s written clarifications of the HMR in the form of letters answering specific questions of the regulated community.  Since the letters are a response to specific questions and sets of conditions, they reflect only the agency’s current application of the HMR to those specific questions and conditions; care must be taken in applying them to your situation.

While these letters of interpretation can be used as a form of guidance in determining your compliance with the HMR, they are not legally-enforceable rights or obligations.  In other words, they are meant to be a guide toward understanding the HMR but do not replace or supersede them.  The letters of interpretation database is regularly reviewed by PHMSA for accuracy and applicability to the most recent version of the HMR.  Letters found to contain inaccurate or inapplicable information are removed and may be revised and reissued as necessary.  A letter which no longer appears on the database may no longer be valid.

HazMat Interpretations can be searched from two databases:

Contact me with any questions you may have about the transportation of hazardous materials by air, highway, vessel, or rail

International and Domestic

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There are many sources of valid information when determining your compliance with the HMR and I like to think that I am one of them.  However you determine compliance, don’t overlook your responsibility to provide triennial HazMat Employee training for all of your employees involved in the handling – shipping, receiving, transportation – of a hazardous material.Daniels Training Services provides HazMat Employee Training