The Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) apply to any person who offers for transportation or transports HM in commerce. A third party who performs regulated HMR functions on behalf of, or under contract to an offeror, carrier, or other regulated entity meets the definition of “a person who offers” or “offeror” and must perform those functions in accordance with all applicable HMR requirements.