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Proposed Rule

New Mailing Standards for Mailpieces Containing Liquids

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Postal ServiceTM.


Proposed rule.


The Postal Service is proposing to revise Mailing Standards of the United States Postal Service, Domestic Mail Manual (DMM) section 601.3.4 to provide for more rigorous packaging requirements for mailpieces containing liquids.


Submit comments on or before August 8, 2018.


Mail or deliver written comments to the manager, Product Classification, U.S. Postal Service, 475 L'Enfant Plaza SW, Room 4446, Washington, DC 20260-5015. If sending comments by email, include the name and address of the commenter and send to with a subject line of “New Standards for Liquids”. Faxed comments are not accepted. You may inspect and photocopy all written comments, by appointment only, at USPS Headquarters Library, 475 L'Enfant Plaza SW, 11th Floor North, Washington, DC 20260. These records are available for review Monday through Friday, 9 a.m.-4 p.m., by calling 202-268-2906.

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Direct questions to Wm. Kevin Gunther at or phone at (202) 268-7208, or Michelle Lassiter at or phone at (202) 268-2914.

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The Postal Service and United States Postal Inspection Service (USPIS) have observed an increased frequency of incidents involving containers of liquids rupturing while in Postal Service networks. A typical result of these incidents is damage to surrounding mailpieces and to Postal Service equipment.

When responding to incidents involving liquid spills, Postal Service employees frequently note that mailpieces containing liquids are often not marked on the outer mailing container as required by DMM 601.3.4. Many of these leaking mailpieces contain plastic primary receptacles. Mailers often do not consider plastic primary receptacles to be breakable, and therefore do not cushion these primary receptacles with absorbent material or include secondary containers, as specified by DMM 601.3.4.

The Postal Service and USPIS have also observed that spills of non-hazardous materials in relatively small quantities can result in damage to surrounding mailpieces and cause temporary equipment shutdowns. This is especially true with viscous or oily substances, such as oils and lotions. These materials are often mailed by First-Class Package Service®. When ruptured, they will frequently leak onto other lightweight mailpieces containing photographs and documents.

This proposed revision would require mailers of all liquids in nonmetal containers, regardless of volume, to provide triple packaging, including Start Printed Page 31713absorbent cushioning materials, sealed secondary packaging, and a strong outer mailing container. The Postal Service is also adding language to encourage the use of locking rings when mailing metal containers with friction-top closures (push-down tops).

The Postal Service believes these new mailing standards will prevent spills in general and reduce the frequency of incidents in which ruptured containers of liquid cause significant damage to surrounding mailpieces. The Postal Service anticipates that this proposed revision will result in decreased cost and time related to spill response, mail decontamination, site cleanup, and provide for an improved customer experience.

If this proposed rule is adopted, the Postal Service will revise and align the language referencing the packaging of nonhazardous liquids located in DMM 601.3.4 and add clarifying language regarding the use of orientation arrows. The Postal Service will also publish an appropriate amendment to 39 CFR part 111 to reflect these changes. Finally, if the proposed rule is adopted, the Postal Service will also make corresponding revisions to Publication 52, Hazardous, Restricted, and Perishable Mail, section 451 to align both publications with regard to the packaging of liquids in its networks.

Although exempt from the notice and comment requirements of the Administrative Procedure Act (5 U.S.C. 553(b), (c)) regarding proposed rulemaking by 39 U.S.C. 410(a), the Postal Service invites public comments on the following proposed revisions to Mailing Standards of the United States Postal Service, Domestic Mail Manual (DMM), incorporated by reference in the Code of Federal Regulations (see 39 CFR 111.1).

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List of Subjects in 39 CFR Part 111

  • Administrative practice and procedure
  • Incorporation by reference
  • Postal Service
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Accordingly, for the reasons stated in the preamble, the Postal Service proposes that 39 CFR parts 111 and 113 be amended as follows:

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1. The authority citation for 39 CFR part 111 continues to read as follows:

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Authority: 5 U.S.C. 552(a); 13 U.S.C. 301-307; 18 U.S.C. 1692-1737; 39 U.S.C. 101, 401, 403, 404, 414, 416, 3001-3011, 3201-3219, 3403-3406, 3621, 3622, 3626, 3632, 3633, and 5001.

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2. Revise the following sections of Mailing Standards of the United States Postal Service, Domestic Mail Manual (DMM), as follows:

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Mailing Standards of the United States Postal Service, Domestic Mail Manual (DMM)

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600 Basic Standards for All Mailing Services

601 Mailability

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3.0 Packaging

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3.4 Liquids

[Revise the introductory paragraph of 3.4 to read as follows:]

Mailers must mark the outer container of a mailpiece containing liquid to indicate the nature of the contents, and include orientation arrows in accordance with Publication 52, section 226. Mailers must package and mail liquids under the following conditions:

[Revise 601.3.4a to read as follows:]

a. Use screw-on caps with a minimum of one and one-half turns, soldering, clips, or similar means to close primary containers containing liquids. Do not use containers with friction-top closures (push-down tops) except as provided in 3.4d.

[Renumber the current 601.3.4b through 601.3.4d as the new 601.3.4c through 601.3.4e and add a new 601.3.4b to read as follows:]

b. The use of locking rings or similar devices is encouraged when mailing containers with friction-top closures (push-down tops).

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[Revise renumbered 601.3.4d to read as follows:]

d. All nonmetal containers of liquids, including plastic containers, and metal containers with friction top closures, without regard to volume, must be triple-packaged according to the following requirements:

1. Cushion the primary container(s) with absorbent material capable of absorbing all of the liquid in the container(s) in case of breakage;

2. Place the primary container inside another sealed, leakproof container (secondary container), such as a watertight can or plastic bag; and

3. Use a strong and securely sealed outer mailing container durable enough to protect the contents and durable enough to withstand normal processing in Postal Service networks.

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Ruth Stevenson,

Attorney, Federal Compliance.

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[FR Doc. 2018-14382 Filed 7-6-18; 8:45 am]