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:
- 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: “Do any of your articles contain anything liquid, fragile, perishable, or potentially hazardous, such as lithium batteries, perfume, mercury or aerosols?”
- If the contents are mailable, determine the specific quantity limitations, labeling, and packaging requirements that apply.
- With the exception of destination-entered mail entered at a destination delivery unit (DDU), destination sectional center facility (DSCF), or destination network distribution center (DNDC), verify that all mailpieces containing mailable hazardous materials are presented separately from mailpieces not containing hazardous materials.
- Refuse (as permitted in POM 139) to accept material that does not meet the applicable requirements for mailing and refer the circumstances to the local postmaster or PCSC for a mailability ruling under 213 or 215, as appropriate.
- If a mailpiece containing a diagnostic (clinical) specimen is in a sack or tub, PS Tag 44 must be attached to ensure that the sack or tub will be emptied at the processing point.
- With the exception of destination-entered mail entered at a DDU, DSCF, or DNDC, ensure mailpieces containing hazardous materials remain separated from other mailpieces and are placed into labeled containers further separated by transportation type. See 327.1a and 327.1b.
- See 253 for guidance regarding hazardous materials found in lobby drops or retail collection boxes.
See Chapter 7 for guidelines Postal Service acceptance personnel must follow when handling hazardous materials, restricted matter, or perishable matter to be transported by air.