Compliance
Prohibited and Restricted Shipping Items
Effective date: June 8, 2026 Version: 1.0 Company: Gridlock Box LLC, 203 Circle, Terre Haute, IN 47803 Contact: support@gridlockbox.com
Shipping Compliance and Prohibited Items
Gridlock inserts are passive packaging. You, the seller, choose what you ship inside a Gridlock insert and which carrier you use. You are responsible for following all USPS, FedEx, and UPS rules and all federal, state, and local laws for the items you ship.
Some items cannot be mailed, and some can be mailed only by ground or surface transportation with special packaging and labeling. Common examples for sellers: lithium batteries and battery electronics, perfume, cologne, nail polish and remover, hand sanitizer, aerosols and body sprays, fragrance and essential oils, gel-wax candles, vapes and e-cigarettes (generally nonmailable, with only narrow USPS-authorized exceptions not available for ordinary consumer mailing), cannabis, ammunition, and strike-anywhere matches. Fueled lighters can ship by surface only, under the USPS packaging rules. The controlling rules are in USPS Publication 52 and the federal Hazardous Materials Regulations (49 CFR).
Gridlock Box LLC does not inspect package contents, does not handle the product shipped inside the insert, and is not the shipper of your product. Gridlock Box LLC is not responsible for any item you ship in an insert or for any carrier penalty, rejection, delay, damage, or loss that results from what you ship or how you ship it. When in doubt, check USPS Publication 52 or your carrier before shipping.
Categorized List
This list is a guide, not a complete statement of carrier or legal requirements. Rules change; check USPS Publication 52 and your carrier before shipping. International rules differ from the domestic United States rules described here.
Forbidden (do not ship in a Gridlock insert by USPS)
| Item | Status | Controlling citation |
|---|---|---|
| Vapes, e-cigarettes, ENDS, including liquids, pods, parts, and components, with or without nicotine | Non-mailable by USPS (PACT Act). Carrier mailing to consumers banned. | USPS final rule, Fed. Reg. 2021-22787; 21 U.S.C. 387; 15 U.S.C. 376a |
| Cannabis and marijuana (delta-9 THC over 0.3 percent) | Non-mailable | Controlled Substances Act, 21 U.S.C. 801; Pub 52 453 |
| Ammunition; loaded or charged firearm components | Non-mailable by USPS | 18 U.S.C. 1715; Pub 52 431-432 |
| Strike-anywhere matches | Non-mailable | Pub 52 349; 49 CFR 173 |
| Explosives, fireworks, compressed flammable gas cylinders | Non-mailable | Pub 52 346-348; 49 CFR 173 |
| Standalone or loose lithium batteries shipped by air | Prohibited by air | Pub 52 349; 49 CFR 173.185 |
| Any product shipped by USPS air service that is alcohol-based or otherwise air-prohibited (see Restricted) | Prohibited by that service | Pub 52 343 |
Restricted (mailable with conditions, usually surface or ground only, with packaging and marking)
| Item | Condition | Controlling citation |
|---|---|---|
| Perfume, cologne, aftershave, any alcohol-based fragrance | Domestic SURFACE or GROUND only; air prohibited (no Priority, Priority Express, or First-Class air). Consumer-commodity packaging; up to 16 oz per package; sealed plus absorbent; mark "Surface Only" as a consumer commodity or limited quantity (the older ORM-D marking is obsolete). International prohibited. | Pub 52 343; 49 CFR 173 Class 3 |
| Nail polish and nail-polish remover | Flammable liquid; surface or ground only as consumer commodity | Pub 52 343 |
| Hand sanitizer and alcohol-based cleaners or wipes | Flammable; surface or ground only | Pub 52 343 |
| Aerosols: hairspray, deodorant, air duster | Consumer-commodity surface only; specific packaging and marking; spray paint frequently refused | Pub 52 342 |
| Filled or charged lighters containing flammable fuel or gas | Mailable by SURFACE only under Pub 52 Packaging Instruction 3C, with the required packaging and marking; air prohibited | Pub 52 349; Packaging Instruction 3C; 49 CFR 173 |
| Fragrance oils, essential oils, scented oils, reed-diffuser liquid | Hazardous if flash point at or below 140 F; treat as flammable, surface or ground only; otherwise permitted | Pub 52 343; 49 CFR 173.120 |
| Gel-wax or fragrance-heavy candles | May be hazmat depending on flash point and additives; solid paraffin or soy candles generally permitted | Pub 52 343 |
| Lithium batteries installed in or packed with the equipment they operate | Mailable domestically by air or surface if Pub 52 349 and Packaging Instruction 9 are met | Pub 52 349; Packaging Instruction 9D/9E |
| Used, damaged, or defective electronic devices containing lithium batteries | Ground or surface only, prohibited by air; mark "Restricted Electronic Device" and "Surface Transportation Only" | Pub 52 349 |
| Hemp-derived CBD (delta-9 THC under 0.3 percent) | Mailable; seller must retain compliance records (lab results, licenses) for at least 2 years | Pub 52 453.37 |
| Strong or rare-earth magnets | Magnetized-material limits, primarily for air (field-strength thresholds) | Pub 52 349; 49 CFR 173.21 |
| Corrosives, oxidizers, peroxide-based products | Class-dependent; many surface only or non-mailable | Pub 52 344-345 |
| Perishable or biological materials | Class-dependent special handling | Pub 52 Chapter 5 |
Permitted (typical, no hazmat condition by itself)
| Item | Note | Controlling citation |
|---|---|---|
| Solid jewelry (non-battery) | Permitted; value and insurance are a seller choice | Pub 52 (no restriction) |
| Solid soap, bar soap, bath bombs (non-flammable) | Permitted | Pub 52 (no restriction) |
| Solid paraffin or soy candles, no gel wax, normal additives | Permitted | Pub 52 343 by exclusion |
| Phones, cameras, power banks, and similar with the lithium battery installed, sold new | Permitted by surface; see the Restricted installed-battery condition | Pub 52 349 |
| Dry cosmetics, powders, non-flammable lotions | Permitted | Pub 52 (no restriction) |
Your Acknowledgment
By placing an order, you confirm you are responsible for following all USPS, FedEx, and UPS shipping rules and all applicable laws for the items you ship in Gridlock inserts. You understand Gridlock Box LLC does not inspect package contents and is not responsible for what you ship. You will not ship prohibited items, and you will follow ground-only and packaging rules for restricted items such as lithium batteries, perfume, aerosols, and flammable liquids.