Nuclear Denisty Gauge
Pipeline and Hazardous Materials Safety Administration · Sep 6, 2007 · Reference No. 07-0129
Interprets: 49 CFR § 171.1
Reggie’s quick take
A user of a nuclear density gauge asked whether federal hazardous materials rules apply when the gauge is driven from an approved storage location to a temporary jobsite and back, sometimes over several months, with the gauge kept at the user's home or hotel in between. The agency said yes: the Hazardous Materials Regulations (49 CFR Parts 171-180) apply to these trips, and the gauge counts as temporarily stored incidental to movement while at home or in a hotel room (§ 171.8). The user must also follow NRC and applicable state requirements.
Written by AI (Claude) on Oct 22, 2026. Robots make mistakes and leave things out, so the letter below is what counts. Not legal advice.
This responds to your June 21, 2007 letter regarding the transportation of a nuclear density gauge. As discussed in your June 20, 2007 telephone conversation with Mr. James Williams of the Office of Hazardous Materials Technology staff, you ask if the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) apply to your scenario described below.
According to your letter, over a period ranging from several days to several months, a gauge user drives the gauge from an NRC-approved location to a temporary jobsite, and then back and forth between his home (or hotel) and that jobsite. You ask if the HMR apply to the transportation of the nuclear density gauge under this scenario.
The HMR apply to the transportation of hazardous materials in commerce, as specified in § 171.1, including storage incidental to movement under § 171.8. Transportation of the nuclear density gauge from an NRC-approved location to a temporary jobsite and back and forth between home or hotel and that jobsite is subject to the HMR. Moreover, the nuclear density gauge is being temporarily stored incidental to movement while in the gauge user's home or hotel room.
In addition, the user is subject to NRC and applicable State requirements when transporting the nuclear density gauge, including storage incidental to movement.
A letter of interpretation applies the regulations to the facts the requester described. It isn’t a regulation and isn’t legal advice. The agency’s copy.