USPS Homepage

25 Basic Guidelines for Acceptance and Dispatch

251 Guidelines for Acceptance Personnel

Postal Service personnel may not open mail sealed against inspection except under the circumstances described in ASM 274. Accordingly, knowledge of the content of such mail may be obtained directly from the mailer (e.g., a mailer may ask questions about mailing requirements or mark the outside of the mailpiece to indicate the contents) or indirectly through leakage or other escape of the contents. Subject to the applicable restrictions, acceptance personnel must:

  1. Determine the mailability of all hazardous materials, perishable matter, or otherwise restricted matter offered for mailing at a retail unit or business mail entry unit (BMEU). This process must include a thorough inspection of all sides of the mailpiece for evidence of hazardous materials (e.g., markings). At retail units, mailers must be asked the question: “Does this parcel contain anything fragile, liquid, perishable, or potentially hazardous, including lithium batteries and perfume?”
  2. If the contents are mailable, determine the specific quantity limitations, labeling, and packaging requirements that apply.
  3. Refuse (as permitted in POM 139) to accept any material that does not meet the applicable requirements for mailing and refer the circumstances to your local Postmaster or PCSC for a mailability ruling under 213 or 215, as appropriate.
  4. If the parcel containing a diagnostic (clinical) specimen is in a sack or tub, PS Tag 44 must be attached to ensure that the sack will be emptied at the processing point. Dispatch all mailable hazardous materials as applicable to the class and content of each mailpiece.

See Chapter 7 for guidelines Postal Service acceptance personnel should follow when handling hazardous materials, restricted matter, or perishable matter to be transported by air.