UN 1791, Hypochlorite solutions, 8 (corrosive), PG II
Pipeline and Hazardous Materials Safety Administration · May 13, 2008 · Reference No. 08-0108
Interprets: 49 CFR § 173.137
Reggie’s quick take
A company asked whether the "PG III" packing group for UN 1791, Hypochlorite solutions, Class 8, was dropped by mistake from the October 1, 2007 Hazardous Materials Table in § 172.101. It was. The PG III entry was removed by error in a December 2006 rule, and PHMSA says it will fix this later. Until then, PG III may still be used for hypochlorite solutions that meet the PG III criteria in § 173.137.
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 is response to your April 11, 2008 letter concerning the Hazardous Materials Table (§ 172.101) entry for "UN 1791, Hypochlorite solutions, 8 (corrosive), PG II" in the October 1, 2007 edition of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180). You asked if the "PG III" designation present in earlier editions of the HMR had been inadvertently deleted.
The answer is yes. The PG III entry for the proper shipping name hypochlorite solutions was inadvertently removed when this entry was revised in a December 29, 2006 final rulemaking published under Docket No. PHMSA-06-25476 (HM-215I; 71 FR 78596, 78622). This error will be corrected in a future rulemaking. In the interim, the PG III entry may continue to be used for hypochlorite solutions that meet the defining criteria for a PG III Class 8 liquid prescribed in § 173.137.
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.