Non-spillable battery exception
Pipeline and Hazardous Materials Safety Administration · Jun 29, 2017 · Reference No. 17-0010
Interprets: 49 CFR § 173.159(b)(2), 49 CFR § 173.159a, 49 CFR § 173.159a(c), 49 CFR § 173.159a(c)(1), 49 CFR § 173.159a(d), 49 CFR § 173.159a(d)(2), 49 CFR § 175.10
Reggie’s quick take
A company asked whether a Cargo Filter System shipped by cargo aircraft is excepted from the Hazardous Materials Regulations. The system has a small air pump and a data logger, both run on non-spillable batteries, and it is meant to be switched on during transport. PHMSA says yes, the system is excepted under § 173.159a(d). The batteries must still meet the battery conditions, including no free-flowing liquid at 55 °C and protection from fire or rupture. The rule that requires preventing accidental activation does not apply, since the device is meant to run during flight. The system must also meet FAA requirements for equipment used on a flight.
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 letter is in response to your February 3, 2017, letter requesting clarification of the Hazardous M
aterials Regulations (HMR; 49 CFR Parts 171-180) applicable to exceptions for non-spillable batteries. You indicate the following information:
You are shipping by cargo aircraft a Cargo Filter System secured in a cargo container.
The Cargo Filter System is comprised of an air circulation device and a transportation data logger intended to ensure a clean environment for a piece of equipment also contained in a cargo container.
The air circulation device includes a small electric air pump, powered by a non-spillable battery.
The data logger is powered by two 9V dry cell batteries that are excepted from the regulations.
The Cargo Filter System is intended to be activated during transportation.
The Cargo Filter System contains no hazardous gas.
Specifically, you ask if the Cargo Filter System as described would be excepted from the HMR.
The answer is yes. Non-spillable batteries are excepted from the HMR in accordance with § 173.159a(d). To meet this exception, the non-spillable batteries must conform to the following:
1) Comply with § 173.159a(c);
2) At a temperature of 55 °C (131 °F), the battery must not contain any unabsorbed free-flowing liquid, and must be designed so that electrolyte will not flow from a ruptured or cracked case;
3) For transport by aircraft, when contained in a battery-powered device, equipment or vehicle must be prepared and packaged for transport in a manner to prevent unintentional activation in conformance with § 173.159(b)(2) of the HMR; and
4) For transport by aircraft, must be transported as cargo and may not be carried onboard an aircraft by passengers or crewmembers in carry-on baggage, checked baggage, or on their person unless specifically excepted by § 175.10.
Note that the third condition listed above, which is found in § 173.159a(d)(2), does not apply because the Cargo Filter System is intentionally activated during the course of transportation. However, the non-spillable battery must still be transported in a manner which protects against a fire, violent rupture, explosion, or dangerous evolution of heat. See § 173.159a(c)(1) regarding a battery necessary for operation of equipment. Additionally, as a piece of equipment intended to be operated during a flight, the Cargo Filter System must comply with Federal Aviation Administration requirements.
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.