Battery Electrolyte Refill Unit as Limited Quantity
Pipeline and Hazardous Materials Safety Administration · Jul 18, 2001 · Reference No. 01-0145
Reggie’s quick take
A company that ships battery electrolyte refill units asked whether the units can move as limited quantities under § 173.154(b)(1) of the HMR and the IMDG Code. Each unit has two reservoirs of up to 465 ml each, sealed in plastic and packed in a UN 4G box. The agency said yes. Each reservoir counts as a separate inner packaging under § 171.8, so the unit can ship as a limited quantity.
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 May 29, 2001 letter requesting clarification of the requirements for the shipment of a battery electrolyte refill unit under the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) and the International Maritime Dangerous Goods (IMDG) Code. Specifically, you ask whether the battery electrolyte refill unit may be shipped under the limited quantity provisions in § 173.154(b)(1) of the HMR and Amendment 30-00 of the IMDG Code.
According to your letter and enclosed sketch, the battery electrolyte refill unit consists of a single molded plastic device having two independent reservoirs of equal volumes not exceeding 465 ml each. The two reservoirs each contain three "cells," having a volume of 155 ml each, that are in communication with one another. The single molded plastic device is hermetically sealed with a plastic bag and then placed into a UN 4G box. You ask whether each independent reservoir is considered to be an "inner packaging" as defined in § 171.8 of the HMR.
The answer is yes. Consistent with § 171.8, each independent reservoir of the refill unit is a separate inner packaging. Thus, a battery electrolyte refill unit as described in your letter may be shipped as a limited quantity under Amendment 30-00 of the IMDG Code and § 173.154(b)(1) of the HMR. Amendment 30-00 of the IMDG Code limits the maximum quantity of each receptacle to 500 nil; the limited quantity provisions in § 173.154(b)(1) of the HMR authorize a maximum of 1 liter in each inner packaging.
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.