Michael Turner
Standard rules applied by major airports: individual liquid containers must not exceed 100 ml (3.4 fl oz) and the collective volume must fit inside a transparent, resealable 1‑litre (quart) bag. In the United States the TSA uses the 3‑1‑1 rule: 3.4 fl oz containers, 1 quart bag, 1 bag per traveler; EU/UK rules follow the 100 ml / 1‑litre format.
Medical and infant supplies: prescription liquids, insulin and baby formula exceeding 100 ml are permitted but must be declared at security and may require supporting documentation or additional screening. Label prescription containers and keep relevant paperwork accessible for inspection.
Duty‑free purchases: goods sold in tamper‑evident bags with an intact receipt are generally accepted in the cabin, however re‑screening at a connecting departure may subject them to the same liquid limits – verify connection‑airport procedures before transit.
Practical packing tips: use travel‑sized containers clearly marked 100 ml, consolidate liquids to minimize the number of units, place the clear bag in an outer pocket for quick removal at checkpoints, and avoid aerosols or pressurised items that exceed airline hazardous‑materials limits. Checked baggage permits larger volumes but remains subject to airline weight and dangerous‑goods regulations.
Before departure, check the specific carrier and airport webpages for any deviations or additional restrictions; discrepancies between local security and airline policies occur, so a quick confirmation prevents confiscation and delays.
Carry-on liquid limits and practical packing rules
Pack only containers of 100 ml (3.4 fl oz) or less, all placed inside a single transparent resealable bag with total capacity up to 1 litre; 1 bag allowed per passenger through security screening.
United States follows the TSA 3-1-1 standard (one quart-sized bag, containers ≤3.4 fl oz); European Union and most international airports use 100 ml per container and a maximum 1 L clear bag. Multiple small containers are acceptable if they fit without overstuffing.
Exemptions include prescription medications, baby formula and breast milk, and medically necessary liquids; these may exceed 100 ml but require declaration at security and supporting documentation or original packaging. Duty-free liquids purchased after security are permitted in tamper-evident security bags with receipt; retain the sealed bag when transiting through additional checkpoints.
Frozen items that are completely solid pass screening; partially thawed or slushy items are treated as liquids and subject to limits. Aerosols and sprays follow the same container-size rules and may face airline-specific restrictions for pressurized cans.
Practical steps: decant products into labeled travel containers of 100 ml or less, use a clear resealable bag that lies flat, place medications and baby supplies in an easily accessible pocket for inspection, and keep receipts for duty-free purchases. For long itineraries or larger quantities, place excess liquids in checked baggage or arrange shipping.
Regulations differ by country and airport; verify departure and transfer airport rules online and consult the airline’s carry-on policy for size and weight allowances to avoid surprises at the gate.
Which liquids count as containers under the 100 ml airport rule
Pack liquids, gels, aerosols, creams and pastes in containers of 100 ml (3.4 fl oz) or smaller and place them together inside a single transparent resealable plastic bag with a maximum capacity of 1 litre (approx. 20 x 20 cm); present the bag separately at security screening.
Included items: beverages and soups; shampoos, conditioners, shower gels and liquid soaps; toothpastes and oral gels; creams and lotions (including sunscreens and after-sun); liquid foundations, concealers, serums and oils; perfumes and sprays; aerosols that dispense liquid or foam; gels such as hair styling products; liquid deodorants and roll-ons; medicinal syrups and eye/ear drops; liquid or semi-liquid foods such as yogurt, sauces and syrups.
Rule is applied to the container’s labelled maximum capacity rather than its current fill level: a 150 ml vessel is non-compliant even if it contains only 30 ml. Use containers marked 100 ml/3.4 fl oz or smaller; refillable travel containers are acceptable provided they display the correct capacity.
Exemptions include prescription medicines and infant feeding items in quantities exceeding 100 ml; these must be presented separately for inspection and may require proof such as a prescription or infant travel documents. Declare such items at the security checkpoint.
Retail purchases made after security (tax-free or duty-free) are permitted if sealed in a tamper-evident bag with the receipt clearly visible and dated the same day; connecting flights or transfers can affect acceptance, so check transfer-point screening requirements before opening sealed purchases.
Solid cosmetics (soap bars, solid deodorants, powder compacts, stick foundations and solid perfumes) are not treated as liquid items. Frozen liquids are acceptable only if completely solid at screening. Aerosol and pressurised containers count as liquid items and are additionally subject to carrier restrictions regarding flammability and pressure; consult the airline before travel for aerosols.
Practical steps: choose travel-sized containers labelled 100 ml/3.4 fl oz, consolidate all compliant items into one 1-litre clear bag, keep the bag easily accessible at the top of your cabin bag for security inspection, and retain receipts and medical documentation for items that exceed the volume limit.
Calculate allowed containers from container volume and single-bag limit
Apply this formula immediately: allowed_units = floor(bag_capacity_ml ÷ container_volume_ml). Each container must be at or below the per-item limit (commonly 100 ml) and all units must physically fit inside a single transparent resealable bag that closes.
Step-by-step calculation
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Confirm limits: per-item limit (standard 100 ml) and single-bag capacity (EU/UK standard 1 L = 1000 ml; US/TSA standard quart ≈ 946 ml).
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Convert volumes to millilitres for precision (1 L = 1000 ml; 1 fl oz ≈ 29.57 ml).
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Compute allowed_units = floor(bag_capacity_ml ÷ container_volume_ml). Example: 1000 ÷ 100 = 10; 946 ÷ 100 = 9.
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For mixed sizes, sum individual volumes and verify total_volume ≤ bag_capacity_ml AND that items fit when arranged flat inside the sealed bag.
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Adjust for shape: rounded or bulky containers often reduce the practical count below the mathematical result.
Examples and packing recommendations
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Single-size examples (mathematical maximum): 100 ml → EU: 10 units; US: 9 units. 75 ml → EU: 13 units; US: 12 units. 50 ml → EU: 20 units; US: 18 units.
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Mixed-size calculation: convert each item to ml, add them, then compare to bag_capacity_ml. If total exceeds capacity or the bag will not close, remove or replace items until closure is possible.
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Packing tips to maximize usable units: choose flat or rectangular travel containers, remove retail boxes, place items side-by-side to avoid wasted space, nest thin sachets at edges.
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Regulatory note: aerosols, pressurised or flammable liquids may be subject to additional restrictions beyond size and bag capacity; check the specific airport or carrier rules before departure.
Allowed extra containers for medication, baby food and medical needs
Carry medically necessary liquids exceeding 100 ml in cabin, declare them at security and present prescriptions or a clinician’s note; security screening and additional testing will follow.
Documentation and screening
Required paperwork: original prescription labels, pharmacy dispensed labels, a dated doctor’s letter specifying medication name, dosage and necessity, and a simple medication list. For infant feeds include child’s date of birth or travel itinerary on a printed note.
What to expect: officers will ask for declaration, X‑ray screening, possible opening of containers and swab testing. In the United States the Transportation Security Administration permits medically necessary liquids above 3.4 oz (100 ml) once declared; EU and UK authorities apply similar exceptions but final allowance rests with the screening officer.
Packing and practical tips
Keep medicated liquids and infant nutrition in original packaging or clearly labelled bottles; place them separately in an easy‑to‑reach part of the carry‑on for inspection. Pack measured amounts that match the trip duration (typical long‑haul allowance accepted by many passengers: 1–2 litres of formula or expressed milk), plus a small reserve.
Injectable medications, syringes and portable pumps should travel in cabin with prescription documentation; battery packs and chargers go in carry‑on. For temperature‑sensitive items use insulated pouches and frozen/refrigerated gel packs – declare these at screening as gels/ice packs may require extra checks.
Carrying duty-free alcohol and perfume through security and connecting flights
Keep duty-free alcohol and perfume sealed inside the tamper-evident bag provided at purchase with the original receipt visible; if a connection requires passing through another security checkpoint, place those items into checked baggage at the transfer desk or purchase again after the checkpoint.
Request the retailer to seal products in a clear STEB and to print date, time and flight number on the receipt; security personnel generally permit liquids over 100 ml only when presented sealed together with that receipt.
Connections that remain inside the sterile zone: retain the sealed bag and carry boarding passes for onward travel. Connections requiring terminal change, customs clearance or re-check on a different carrier: surrender items to the transfer desk for tagging into the hold or transfer them to checked baggage before re-screening.
Inflight purchases should be treated the same as airport duty-free: keep the sealed packaging and receipt; when continuing on a domestic sector after international arrival or when re-clearing security, move those items to checked baggage at the gate or transfer desk to avoid confiscation.
Practical steps
Before purchase: confirm transfer screening procedures on the airline or airport website. At purchase: insist on a tamper-evident bag and a receipt showing date/time and flight number. At transfer: verify whether re-screening will occur; if yes, arrange for checked re-routing or plan to repurchase after security. If uncertain: present the sealed item and paperwork to security or airline transfer staff for specific instruction rather than risking loss at the checkpoint.
Variations by airline and destination: when stricter limits apply
Check departure-airport security pages and the operating carrier’s policy at least 48 hours before travel; if officials publish tightened liquid rules, move containers over 100 ml into checked bags or buy sealed duty-free in a tamper-evident bag with receipt and keep it until final arrival.
Typical scenarios that trigger tighter restrictions and the precise actions to take:
| Scenario | Typical extra restriction | Action |
|---|---|---|
| Departures from EU/EEA/UK airports | Standard 100 ml per container inside a single 1‑litre clear bag; occasional enhanced screening at specific airports | Follow 100 ml rule; if transfer involves re‑screening, store large containers in checked hold or buy duty‑free in sealed bag and keep receipt |
| Departures from US/Canada | 3.4 oz (~100 ml) per container, quart-size bag; secondary checks more frequent at some hubs | Pack to 3.4 oz limit; keep liquids accessible for inspection; put excess in checked baggage |
| Transfers that require re‑screening (connecting flights through different security zones) | Duty‑free bottles may be treated as regular carry containers and seized if re‑screened | Prefer sealed duty‑free with receipt when no re‑screening expected; otherwise place purchased items in checked hold before the re‑screening point |
| Airports under elevated threat or temporary local restrictions | Ad hoc bans on aerosols or reduced container volume limits announced short‑term | Monitor official airport/security announcements; transfer liquids to checked baggage if any doubt |
| Some regional and low‑cost carriers | Stricter cabin bag size/weight rules that indirectly force liquids into checked bags | Verify permitted cabin kit dimensions; if space is limited, place non‑essential liquids in the hold; use compact organizers |
Practical packing tips tailored to stricter regimes: use clear resealable bags sized to local rules, label medicinals and baby feeds, and consolidate products into compliant travel containers. When cabin space is tight, a small soft kit inside a daypack or best drawstring gym bag keeps liquids accessible for inspection. For checked options, choose a protective case listed among recommendations such as best luggage for amtrak trip.
If carrying concentrated cleaning solutions or homemade toiletry blends, test and decant them into properly labeled travel vials and follow a trusted DIY formula like how to make natural scrubber; then decide carriage method based on departure and transfer screening rules.
Practical packing and presentation tips to avoid confiscation at security
Place all liquid containers in a clear resealable pouch in an external pocket so the pouch can be removed and presented without unpacking the main carry-on bag.
Packing techniques to prevent rejection or spills
- Keep original labels on commercial products; if decanting, label each container with content name and date using waterproof tape and permanent marker.
- Use a hard-sided toiletry case or small spill tray inside the bag; surround bottles with soft items (socks, cloth) to reduce impact damage.
- Seal pump tops and screw caps with a short band of tape and an inner layer of cling film to prevent leakage during pressure changes.
- Place each container inside a small secondary zip-seal pouch before inserting into the main clear pouch; this contains drips and isolates odours.
- Pack aerosols upright and away from heat sources; bulky aerosol cans may be rejected at many checkpoints–carry in checked bag if unsure.
- For perfumes and high-value liquids, keep the manufacturer box and purchase receipt readily accessible to prove authenticity if asked.
Presentation at the checkpoint
- Withdraw the clear pouch from the external pocket and place it on the belt first; fold the pouch flat to speed X‑ray reading.
- If a security officer requests removal of a specific item, hand it over separately rather than fidgeting with the whole bag.
- Keep prescriptions, proof of medical need, and baby food receipts in a single visible folder and present them when requested; do not bury paperwork inside the bag.
- When asked to transfer liquid into the tray, place the tray at the centre of the belt to avoid sliding or tipping on conveyor corners.
- For tight connection times, carry essential liquids in an easily reachable external compartment to reduce delays and minimise the chance of disposal due to rushing.
Adopt these steps consistently: tidy presentation reduces secondary inspections and lowers the risk of confiscation due to unreadable labels, leaks, or inaccessible documentation.
FAQ:
How many bottles of liquids can I bring in my hand luggage?
Most airports follow the rule that each liquid container must hold no more than 100 ml (or 3.4 fl oz). All such containers must fit inside a single transparent resealable plastic bag with a total capacity of about 1 litre (quart-sized). The number of bottles you can carry depends on their size and the bag’s capacity — for example, you can usually fit several 100 ml bottles in one bag. If you need to carry larger amounts, put them in checked baggage or buy them after security.
Can I bring a 250 ml bottle that is only half full?
No. Security screens check the size of the container, not the volume of liquid inside. A 250 ml bottle, even if half full, will be treated as over the allowed limit and may be confiscated. Empty containers are usually permitted through screening and can be refilled after security. If you want to carry toiletries in carry-on, transfer them into containers labeled 100 ml or less.
What rules apply to medicines, baby formula and breast milk in hand luggage?
Medicines and baby provisions are generally exempt from the 100 ml limit, but they must be declared at the security checkpoint and may be opened for inspection. Bring only the quantity needed for the trip plus a small spare, and carry prescriptions or a doctor’s note if feasible. For infant feeding, reasonable amounts of milk, formula, sterilized water and baby food are allowed; security officers may test or ask you to taste a sample. Pack these items where they are easy to reach and tell the screening staff about them before scanning.
Are duty-free alcohol or perfume allowed in hand luggage after connections?
Duty-free items bought after security are normally placed in tamper-evident sealed bags with the purchase receipt and are allowed through to your final destination when you do not leave the secure zone. If you have a connecting flight and must pass through another security checkpoint, rules vary by airport and country — the sealed bag may not be accepted at the next filter and you could be asked to place the items in checked baggage. Keep receipts, ask shop staff about transfer rules, and consider checking fragile or large bottles if you will clear security again during your trip.
