Airport Security & TSA Rules Decoder
Standing in the airport security line wondering if your powerbank is allowed, why you have SSSS printed on your ticket, or if your cream will be confiscated under the 3-1-1 rule? Use our instant calculators and security guide.
Can I Take My Powerbank on the Plane?
Airlines regulate portable chargers by Watt-Hours (Wh), not mAh. Enter your battery’s mAh capacity to calculate Wh.
Approved for cabin carry-on without airline permission. Strictly prohibited in checked luggage.
Will Security Confiscate My Bottle?
Enter the printed container capacity on your shampoo, perfume, or cream bottle.
Fits under the 100 ml (3.4 oz) carry-on limit. Must fit inside a single 1-quart zip-top transparent bag.
Mystery Boarding Pass Security Codes (SSSS, PRE, SEQ#)
Find out why you couldn't print your boarding pass at home or what those random letter codes printed across your ticket mean.
What it means: You have been flagged for extensive enhanced security screening by the government.
What it means: Trusted traveler status verified for domestic US flights.
What it means: The numerical order in which you checked in for this specific flight.
What it means: Internal airline instruction for passenger accommodations.
Powerbanks & External Battery Packs
Lithium-ion batteries carry a thermal runaway fire risk that cargo fire suppression cannot easily extinguish. Most 10,000 to 26,800 mAh powerbanks are under the 100 Wh limit.
💡 Pro Tip: Wh = (mAh × 3.7V) ÷ 1,000. If your powerbank does not have the Wh or mAh printed on its shell, TSA officers will confiscate it.
Liquids, Pastes, Creams & Gels (3-1-1 Rule)
Applies to shampoo, toothpaste, peanut butter, perfume, sunscreen, and foundation. Even if a 200 ml bottle only has 20 ml left inside, it is confiscated because the container capacity exceeds 100 ml.
💡 Pro Tip: Medically necessary liquids (insulin, saline) and baby formula are exempt from the 3.4 oz limit but must be declared.
Duty-Free Liquids in Sealed STEB Bags
Purchased at airport duty-free shops, the liquid must remain inside an official clear Security Tamper-Evident Bag (STEB) with the receipt visible from within 48 hours.
💡 Pro Tip: Never open the sealed STEB bag until you reach your final final destination, especially during transit layovers.
Disposable Lighters & Safety Matches
Torch lighters (blue flame jet lighters) are strictly forbidden everywhere. One standard lighter or one book of safety matches must be carried in your pocket, never in checked luggage.
💡 Pro Tip: Electronic USB rechargeable arc lighters are treated as lithium batteries and must be in carry-on.
Scissors & Pocket Knives
Standard swiss army knives, utility blades, and box cutters will be immediately seized at checkpoint. Pack them securely wrapped in your checked luggage.
💡 Pro Tip: Small nail scissors with blades under 4 inches from the pivot point are technically allowed by TSA, but international airports often confiscate them.
E-Cigarettes & Vapes
Vapes contain lithium batteries and heating elements. They must be kept in the cabin where any accidental activation or smoke can be observed immediately.
💡 Pro Tip: Empty your tank before flying! Cabin pressure changes will force e-liquid out of the tank into your pocket.
Aerosols & Deodorants
Solid stick deodorants have zero liquid limits and can be full size in carry-on. Spray/aerosol deodorants must comply with the 100 ml liquid rule.
💡 Pro Tip: Switch to stick or roll-on deodorant to save space in your 1-quart liquid bag.
Why Lithium Batteries Are Banned from Checked Baggage
Thermal Runaway Danger
Lithium-ion cells in powerbanks and vapes contain volatile liquid electrolytes. When crushed, short-circuited, or overheated, they can enter an unstoppable chemical chain reaction called thermal runaway, exceeding temperatures of 1,000°F (538°C).
In the aircraft passenger cabin, flight attendants have specialized fire containment bags and halon extinguishers to smother a smoking device in seconds. In the cargo hold beneath the floor, an undetected battery fire can overwhelm automated cargo halon systems.
The 100 Wh Mathematical Standard
Aviation safety agencies globally (FAA, EASA, ICAO) cap personal electronics at 100 Watt-Hours (Wh). You can find your battery's Wh using Ohm's energy formula:
Watt-Hours (Wh) = (mAh × Voltage) ÷ 1,000
Since standard lithium battery cells output 3.7 Volts, a 20,000 mAh charger provides (20,000 × 3.7) ÷ 1,000 = 74 Wh, making it 100% legal to bring into the cabin!