Michael Turner
Rule summary: Security checkpoints apply the 100/1 rule: individual liquid, gel, cream, paste and aerosol containers must not exceed 100 ml, and all such containers carried in the cabin must fit comfortably into one clear resealable bag holding no more than 1 litre. Only one transparent bag per passenger is permitted for screening.
Which items count: Sprays, styling gels, leave-in creams, serums, foam and similar formulations are treated as liquids/gels and are subject to the 100 ml limit. Solid bars (shampoo bars, solid conditioners, wax bars) are not classed as liquids and may be carried outside the clear bag. Aerosols intended for personal care generally qualify under the same volume restriction; some aerosol types with flammable propellants face additional restrictions or bans, so check the carrier’s list before travel.
Exceptions and special cases: Prescription medicines, essential medical liquids and infant milk/formula may exceed 100 ml but must be declared at screening and are subject to extra inspection. Duty-free purchases packaged in a sealed tamper-evident bag with receipt are usually permitted through security; for transfers between flights, keep the sealed packaging intact and carry receipts to avoid confiscation at connecting airports.
Practical recommendations: decant larger containers into travel-size bottles clearly labeled ≤100 ml, prefer solid alternatives where possible, stow sprays with safety caps, and place the clear bag at the top of cabin carry-on for quick removal at security. For quantities above regulated limits, place items in checked baggage or ship ahead. Verify specific airline and departure/arrival airport restrictions before departure to avoid last-minute disposal at the checkpoint.
Which styling items are classified as liquids, gels or aerosols under the 100 ml rule?
Treat sprays, foams, mousses, serums, oils, creams, gels and pressurised cans as liquids/gels/aerosols – each container must show 100 ml or less (or equivalent) to be carried in a single transparent 1‑litre resealable bag.
Typical examples that count as liquids/gels/aerosols: shampoo, conditioner, leave‑in treatments, styling mousse, hair spray, aerosol dry shampoo, texturizing and sea‑salt sprays, thermal protectant sprays, leave‑in serums and oil treatments, gel styling agents, liquid pomades and cream waxes that squeeze or pour from their packaging.
Items usually not classed as liquids: solid bars (solid shampoo bars, solid pomades, stick waxes), dry powdered formulations in a shaker (non‑aerosol dry shampoo), and fully solid clays that do not flow or spread at room temperature; these are treated as solids and not subject to the 100 ml container limit.
How to decide: if the formulation pours, squeezes, sprays, foams or spreads as a cream/gel it is subject to the 100 ml rule; pressurised cans are classified as aerosols regardless of whether net volume is shown in ml. The printed container volume governs acceptance – if only weight is given, check manufacturer info or pack into a labelled ≤100 ml travel container.
Exceptions and practical notes: medically required liquid treatments and infant feeds are allowed outside the 100 ml limit but must be declared at screening; duty‑free aerosols purchased in the airport may exceed 100 ml if sealed in a tamper‑evident bag with receipt. To avoid refusals, decant into clear travel bottles marked with capacity, keep all containers in one visible 1‑litre bag, and verify airline or airport screening guidance for regional variations.
How to measure and package shampoos, conditioners and leave-in treatments for carry-on
Place each shampoo, conditioner and leave-in treatment into containers of 100 ml (3.4 fl oz) or less and seal every container inside a single transparent resealable bag with a capacity no greater than 1 litre (approx. 20×20 cm).
Measuring and transferring
Use a graduated syringe or measuring cup for accuracy; transfer volumes in millilitres. Convert weights where necessary: water-like formulas ≈1 g = 1 ml; creamy or oily formulations typically range 1.02–1.15 g/ml–measure by weight on a kitchen scale if only grams are marked. Fill travel bottles to 90–95% for watery liquids and 80–90% for viscous creams or serums to allow headspace for pressure changes during flight.
Choose containers made of PET or HDPE with screw caps and an inner tamper seal. For pumps, press the dispenser several times before sealing to remove trapped air and then lock or tape the nozzle. Label each container with product name and exact volume (e.g., “shampoo – 100 ml”).
Packing and leak prevention
Apply a single layer of food-grade plastic wrap over the bottle opening before replacing the cap, then tighten the cap fully and wrap the neck with a strip of clear tape for extra protection. Place all sealed containers upright inside the transparent bag; double-bag if any containers are oily or visibly greasy. Store the bag in an outer pocket or top compartment for immediate access during security screening.
| Item | Typical retail size | Recommended travel container | Fill level | Notes |
|---|---|---|---|---|
| Shampoo | 200–500 ml | 50–100 ml PET bottle with screw cap | 90–95% | Use funnel; inner seal + tape; label with volume |
| Conditioner | 150–400 ml | 50–100 ml squeeze or flip-top bottle | 90–95% | Squeeze bottle reduces air pockets; wipe nozzle before sealing |
| Leave-in (serum/cream) | 30–200 ml | 30–100 ml pump or dropper bottle | 80–90% | Thicker formulas need extra headspace; clean dispensing tip |
Powdered and dry styling items: rules and practical steps
Keep powdered styling items and dry solids in containers of 350 mL (12 oz) or less when packed in carry-on; any quantity above 350 mL should be placed in checked baggage or expected to undergo additional screening and possible refusal at security checkpoints.
United States: Transportation Security Administration treats powders over 12 oz (350 mL) as subject to secondary inspection; officers may ask for removal from carry-on and may deny carriage if unable to properly screen. Powdered deodorants, texturizing powders and similar formulations follow this rule; pressurised aerosol dry-shampoos are regulated under different limits.
European Union and many other jurisdictions apply a similar 350 mL threshold and reserve the right to request further inspection or to restrict carriage of opaque powders. Infant formula and medically necessary powders are typically exempt from strict volume limits but must be declared and presented separately for inspection.
Packing recommendations: store powders in clear resealable bags or see-through jars with tight screw caps; label each container with content name and net weight; place small containers inside a dedicated toiletries pouch and keep the pouch accessible near the top of cabin baggage or a cross-body carry–see best messenger bag for across body for compact options. For family travel, use under-seat or stroller storage for quick access – example: best umbrella stroller for older kids.
Screening procedure: present powdered items separately in the screening bin when requested; if an item is large or densely packed, transfer a small sample into a clear container to speed inspection. Home tip: weigh containers on a kitchen scale before departure and split bulk powders into multiple sub-350 mL jars to avoid delays.
Alternatives and damage control: replace bulky powders with single-use sachets, compressed tablets or solid bars (styling wax, solid shampoo) to reduce inspection risk and limit spillages. Keep original packaging for easy identification where possible.
How to carry aerosols (spray, mousse) and comply with airline pressure and quantity limits
Pack aerosols in containers no larger than 100 ml (3.4 fl oz) and place them inside a single clear resealable 1‑quart (1 L) plastic bag for security screening.
Regulatory and labeling checkpoints
- Security rule: 100 ml (3.4 fl oz) per container; all such containers must fit in one clear 1‑quart (1 L) bag (TSA 3‑1‑1 equivalent across most EU/US airports).
- Dangerous-goods markings: UN1950 identifies aerosols. If a can displays a flammable gas symbol, flammable wording, or UN/transport restrictions, that item may be refused for cabin or checked carriage.
- Carrier variance: some airlines impose stricter size or total-quantity limits or ban certain propellants; consult the specific carrier’s dangerous goods page before travel.
Packing and pressure-control procedure
- Use travel-size pump or non-pressurised dispensers where possible; decant into a labeled 100 ml pump bottle to avoid propellant-related risks.
- Verify actuator security: snap-on cap plus an additional piece of tape over the nozzle reduces accidental discharge during pressure changes.
- Seal each can inside its own small zip bag to contain leaks; place these bags inside the clear quart bag required for screening.
- Cushion cans between soft garments in the middle compartment of cabin baggage to minimise impact damage; avoid external pockets and hard-side cases where cans can be crushed against zippers.
- Avoid extreme temperatures: do not leave pressurised cans in a hot car or unchecked cargo hold for extended periods; temperature differentials increase internal pressure and leak/burst risk.
- For checked carriage, follow carrier-specific guidance; never assume checked compartments accept all aerosols – many carriers restrict flammable aerosols or limit total net quantity per passenger under IATA limited-quantity provisions.
If a can ruptures and soils textiles or upholstery, contain the area and use a targeted cleaning method – see how to clean cat puke from carpet for step-by-step stain treatment that works on protein‑ and solvent‑based spills.
- Best-practice checklist before departure: verify container size ≤100 ml; confirm non-flammable labeling or carrier approval; cap + tape nozzle; double-seal in zip bags; place inside clear quart bag.
- Alternatives that reduce risk: solid styling bars, powder texturizers, and refillable pump-foam dispensers designed for travel.
Handling duty-free purchases, transit transfers and differing international security rules
Keep duty-free liquids in the original tamper‑evident bag (STEB/TEB) with the retailer receipt visible; if an intermediate security re‑screening is required, items larger than 100 ml should be moved to checked baggage or purchased after the final security checkpoint.
Practical steps at purchase
Request that high‑volume items be sealed in an STEB and keep the receipt showing date, time, seller and flight number. Verify whether the seal is certified by the airport retailer (many airports stamp or label the bag). Place receipts and seals in an easily accessible compartment of cabin baggage or personal item for inspection.
Transit scenarios and recommended actions
Determine whether the connection requires re‑entry through security (landside) or remains airside; airside transfers usually preserve STEB validity, while landside re‑entry will subject items to the destination’s standard 100 ml/1 L rule and likely lead to confiscation. For flights with mixed carriers or transfer airports known for strict screening, convert oversized liquids to checked baggage at transfer desk, ship to destination, or delay purchase until after the final security checkpoint. When in doubt, confirm rules with the airline and the transfer airport security desk before boarding the first sector.
