USPS AND UPS RULES FOR SHIPPING GLASS BOTTLES OF SAUCE

All three US carriers accept glass bottles of food-grade liquid. What they require, and what they will refuse, is spelled out in their packing standards — and those standards decide whether a damage claim is paid. Here is what applies to a sauce brand.

Is hot sauce a hazardous material?

No. Vinegar- and pepper-based sauces, marinades and dressings are ordinary food products. There is no ORM-D or limited-quantity marking, no hazmat surcharge and no special paperwork. The only sauce-adjacent products that need care are high-proof alcohol-based extracts and bitters; check the alcohol content against the carrier's flammable-liquid threshold before shipping those.

USPS

• Liquids are mailable in glass if the container is securely sealed and packed so it cannot break or leak in transit. USPS's own guidance is to cushion each container and separate multiple containers so they do not touch.
• The parcel must not leak. A wet parcel is set aside and may be returned or discarded.
• Priority Mail includes up to $100 of insurance; Ground Advantage includes up to $100 as well. Claims require proof of value and evidence the item was packed to USPS's standard.

UPS and FedEx

• Both publish packaging guidelines for glass: separate every bottle with dividers or inserts, use a rigid outer box, and provide at least two inches of cushioning between the contents and the box wall for fragile items.
• Declared value coverage starts at $100 per package. Claims are assessed against those packaging guidelines, and "insufficient packaging" is the most common denial.
• Neither carrier handles a "Fragile" sticker differently. It does no harm, but the packing is what matters.

What that means in practice

A pod with a die-cut corrugated insert meets the "separate every bottle" and "cannot move" parts of every carrier's standard on its own. Put it inside a padded mailer or a rigid carton and you have the outer layer. Shrink-band the caps so nothing can leak. That combination is what carriers mean by properly packed, and it is what gets a claim approved if a parcel is crushed anyway.

Labelling

Put the shipping label on the outer layer, not on the pod. Orientation arrows and "This Way Up" markings are optional and, like fragile stickers, do not change handling. What does help: a return address on every parcel and a packing slip inside, so a damaged or opened parcel can find its way back.

International

Food products crossing a border face the destination country's rules, not just the carrier's. Most countries admit shelf-stable sauces for personal use, but commercial quantities may need import documentation, and a few countries restrict vinegar-based products. Check the destination's customs guidance before promising delivery, and ship duties-paid if you can — a surprise duty bill is the fastest way to a refused parcel.

If a bottle breaks anyway

Photograph the parcel, the packing and the bottle before anything is discarded, keep the outer box, and file the claim within the carrier's window (USPS 60 days, UPS and FedEx 60 days from delivery for damage). Send the customer a replacement the same day; the claim is your money back, not theirs.