What Are the Penalties for Mailing Hazardous Materials Improperly?

A person who knowingly mails hazardous material in violation of 39 U.S.C. 3018 or a USPS regulation under it is liable for a civil penalty for each violation, plus clean-up costs and damages (39 U.S.C. 3018(c)(1)). As adjusted for inflation in the October 2026 eCFR text of 39 CFR 233.12, the penalty is at least $393 and up to $156,422 for each violation. The law also directs USPS to prescribe regulations for the safe transport of hazardous material in the mail.

What is prohibited. No person may mail or cause to be mailed hazardous material declared nonmailable by statute or USPS regulation, or mail it in violation of a rule on the time, place or manner of mailing. No person may manufacture, distribute or sell a container, packaging kit or similar device represented, marked, certified or sold for mailing hazardous material if it fails to meet the applicable standards (39 U.S.C. 3018(b)).

Knowing violations. A person acts knowingly with actual knowledge of the facts, or when a reasonable person exercising reasonable care would have had that knowledge (39 U.S.C. 3018(c)(2)).

Separate violations. Each day noncompliant hazardous material is in the mail is a separate violation, and each noncompliant item is a separate violation (39 U.S.C. 3018(c)(3)).

Hearings and penalty amounts. USPS may find a violation only after notice and the chance for a hearing. In setting a penalty, USPS must consider the nature and gravity of the violation, the violator's culpability, prior violations, ability to pay, effect on the business, the impact on USPS operations and other matters justice requires (39 U.S.C. 3018(d) and (e)).

Collection and court actions. USPS may compromise a penalty before suing to collect it. At USPS request, the Attorney General may bring a civil action seeking an injunction, civil penalties or punitive damages, in place of the administrative civil penalty for the same violation (39 U.S.C. 3018(f) and (g)).

Criminal exposure. USPS Publication 52 notes that improper mailings may also bring fines or imprisonment under title 18 of the U.S. Code (Publication 52, 323.1).

Related training. DOT hazmat training is described in the FAQ on PHMSA hazmat employee training.

The FAQ on USPS mailer responsibility for hazardous materials explains labeling and code duties.