Shipping liquids can be frustrating, especially because TSA and air carriers enforce strict compliance rules for safety. Understanding the difference between carry-on, checked luggage, and mailed shipments makes the entire process much easier.
Regulations for Liquids on Planes
When liquids are transported in carry-on luggage, the 3-1-1 rule applies. Each liquid must be in a container of 3.4 ounces or less, placed inside a one-quart, clear resealable bag, and each passenger may carry one bag. Exceptions exist for baby formula, breast milk, medically necessary liquids, and frozen liquids.
Checked luggage allows larger liquid quantities but still requires secure packaging and compliance with airline weight restrictions. Some liquids such as lighter fluid, fuel, spray paint, chemical solvents, and pepper spray are strictly prohibited.
Requirements for Secondary Packaging
When liquids are shipped via UPS, USPS, or commercial air freight, packaging rules focus on preventing leaks. A leak-proof primary container is required, sealed with a screw or snap-on lid. The secondary container must be leak-proof, such as a sealed poly bag or leak-proof liner. The final outer container must be strong, rigid, and typically corrugated.
Orientation labels may be required by certain carriers to ensure the product remains upright during transport. Always declare the liquid at the counter if shipping through a staffed service desk, especially if the product is regulated.
Tips for Packaging
Use absorbent material between primary and secondary containers to capture leaks and reduce mess. Cushion the contents inside the box to reduce movement and protect against impact. Seal every flap of the outer container and reinforce with strapping tape when needed.
By layering leak-proof containers properly and using cushioning, labels, and sealing techniques, liquids can be shipped safely, compliantly, and without damage.
