# Environmentally hazardous substances, liquid, n.o.s. — Postal shipping restrictions by item category For Environmentally hazardous substances, liquid, n.o.s., item category is Environmentally hazardous substances, liquid, n.o.s; carrier is USPS; restriction type is restricted; scope is domestic mail (air and surface); conditions is Hazard class 9, UN3082, packing group III; domestic mail air: 9C; domestic mail surface: 9C, recorded from its source on 2026-08-10. - **Item category:** Environmentally hazardous substances, liquid, n.o.s. _(verified: appears in the quote below)_ - **Carrier:** USPS _(our reading, not quoted from the source)_ - **Restriction type:** restricted _(our reading, not quoted from the source)_ - **Scope:** domestic mail (air and surface) _(our reading, not quoted from the source)_ - **Conditions:** Hazard class 9, UN3082, packing group III; domestic mail air: 9C; domestic mail surface: 9C _(verified: appears in the quote below)_ ## What the source says > Environmentally hazardous substances, liquid, n.o.s. 9 UN3082 III 9C 9C ## Source - https://pe.usps.com/cpim/ftp/pubs/pub52/pub52.pdf Last verified: 2026-08-10. Review by: 2027-08-10. Part of [Postal shipping restrictions by item category](https://referencesource.org/shipping-restrictions-by-class/).