Fluid Ounces: Airport Rules And Regulations Explained

The amount of liquid allowed at airport security has been a topic of concern for travellers for nearly two decades. The current allowance for liquids in carry-on luggage is 3.4 ounces (100ml) per container, and all containers must fit into a quart-sized bag. This is known as the 3-1-1 rule. Liquids that do not meet these limitations will be confiscated. However, there are some exceptions to this rule, such as for baby food and breast milk, medication, and duty-free items. With the advent of new 3-D imaging technology at airports, some have become more lenient with the policy, and it is expected that the limit on liquids will be lifted in the coming years.

The 3-1-1 rule

• 3.4 ounces (100ml) or less per item
• 1 quart-sized, transparent, resealable bag
• 1 bag per passenger

This means that each liquid container can be no larger than 3.4 ounces (100ml). These containers must then fit into a single, quart-sized, transparent, resealable bag. This bag should be easy to open and close and must be presented separately during the airport security screening. Each passenger can carry only one such bag.

It's important to note that there are some exceptions to the 3-1-1 rule. Medications, for instance, are exempt, as are baby formula, breast milk, and juice for infants or toddlers. These items do not need to fit within the quart-sized bag and can exceed the 3.4-ounce limit. Gel ice packs for cooling infant and child beverages are also exempt but must be frozen solid at the time of screening.

For duty-free liquids, you may carry more than 3.4 ounces or 100ml in your carry-on bag if the liquids were purchased internationally and you are travelling to the United States with a connecting flight. The liquids must be packed in a transparent, secure, tamper-evident bag by the retailer and not show signs of tampering when presented to TSA for screening. The original receipt for the liquids must also be presented, and the purchase must have been made within 48 hours.

To avoid any issues at the airport, it's recommended that you check the TSA website or mobile app for updates on the 3-1-1 rule and other security procedures.

Exemptions to the rule

The Transportation Security Administration (TSA) in the United States has a strict 3-1-1 rule for liquids, aerosols, gels, creams, and pastes in carry-on luggage. This rule was introduced in 2006 after a plot to bomb an aircraft using liquid explosives was thwarted.

The 3-1-1 rule limits liquids to 3.4 ounces (100ml) per container, and all liquids must fit into a single, clear, quart-sized bag. Only one such bag is allowed per passenger. However, there are some exemptions to this rule:

Medically Necessary Liquids

Medically necessary liquids are exempt from the 3-1-1 rule. This includes prescriptions that come in liquid, gel, or cream form. Medication should be clearly labelled, and passengers should inform TSA officers of any liquids that are exempt. Medically necessary items that are not completely frozen will be screened using the same procedures as other exempt items.

Childcare Items

Childcare items such as breast milk, infant formula, toddler drinks, and pureed baby food are also exempt from the 3-1-1 rule. Ice, gel, or freezer packs used to cool these items are likewise exempt. Passengers should inform TSA officers that they are carrying these items, and they will be screened separately.

Frozen Liquids

The TSA does not consider completely frozen liquids to be subject to the 3-1-1 rule. However, if the liquid is slushy or partially melted, it must meet the 3-1-1 requirements.

Duty-Free Liquids

Duty-free liquids purchased internationally and transported in a secure, tamper-evident bag with a receipt are exempt from the 3-1-1 rule when travelling to the United States with a connecting flight. However, these items must be screened and cleared, and any signs of tampering will result in the liquids being confiscated.

Non-Alcoholic Drinks

Non-alcoholic drinks and other liquid items purchased in domestic US airport terminal shops or eateries can be brought onto flights.

Liquids in checked luggage

When packing liquids in checked luggage, it's important to do your research and take precautions to avoid leaks and potential hazards. Here are some detailed guidelines and tips for packing liquids in your checked luggage:

Research and Restrictions:

Firstly, determine which liquids are allowed in checked baggage and which require special handling or are prohibited. The Transportation Security Administration (TSA) provides a comprehensive list of liquids, including restrictions on alcoholic beverages over 140 proof. Additionally, refer to the International Air Transport Association's (IATA) list of hazardous materials that are not permitted in checked luggage. It is crucial never to attempt to bring prohibited items on board.

Destination Considerations:

Consider the regulations of your destination. For example, certain U.S. states have restrictions on importing liquor, and travelers to the UK should consult their guidelines for permitted items in checked baggage.

Choosing the Right Liquids:

Evaluate the necessity of packing colored liquids, such as red wine or nail polish, which could damage your belongings if they leak. Assess the availability of similar products at your destination and consider purchasing them locally instead.

Packing Techniques:

To prevent leaks, employ the following techniques:

• Wrap the tops of bottles or containers with tape to secure the caps.
• Place each container in a zipper-top plastic bag and seal it closed.
• Put the sealed bag in a larger bag, pressing out all the air, and seal it again.
• For breakable items, wrap the bundle in bubble wrap or cloth.
• Finally, place the wrapped items in the centre of your suitcase, surrounded by clothing and other soft items.

Alternatively, use a hard-sided plastic or cardboard container for added protection:

• Double-bag the liquid items as described above.
• Place them in a small cardboard box or sealed plastic container.
• Pad the container with crushed newspaper, plastic air pillows, or crumpled plastic bags.
• Tape the box shut and pack it in the centre of your suitcase.

You can also purchase specialised "shippers," such as the VinniBag or the Wine Mummy, which are inflatable, sealable, padded bags designed to minimise the risk of leaks and breakage.

Anticipate Inspections:

Be aware that your checked baggage may be inspected by a baggage security screener. Therefore, it is recommended not to pack valuables or prescription medications in your checked luggage.

Additional Tips:

• Pare down your packing list and consider two-in-one items to save space.
• For large liquid items, invest in travel-sized containers and pour smaller amounts into bottles approved for carry-on luggage.

What constitutes a liquid

The rules for what constitutes a liquid when going through airport security are quite strict. All liquids, gels, creams, aerosols, and pastes must be transported according to the rules. This includes drinks, liquid or semi-liquid foods, cosmetics, toiletries, sprays, and contact lens solutions. Medications and contact lens solutions are limited to 3.4 ounces (100 ml) unless you have a valid prescription or a doctor's note. In that case, you can carry larger amounts, but they must be declared to security officers first.

Breast milk, baby formula, and food and drinks for babies and toddlers are also exempt from the liquid restrictions and are considered "medically necessary liquids." Water for babies is also allowed in "reasonable quantities." Live fish and coral in water are also exempt from the liquid restrictions, provided they are in clear, transparent containers and properly inspected by a TSA officer.

Some countries may have different rules regarding liquids, so it is important to check the regulations for the specific country or airport you are traveling to or from. For example, some European airports have eliminated liquid restrictions due to the advent of computed tomography (CT) scanners at checkpoints. However, other airports, such as Heathrow, are known to be strict with compliance.

It is also important to note that duty-free liquids purchased at the airport or on board an aircraft are allowed in carry-on luggage, even if they exceed 100 ml. However, they must remain unopened and sealed in a security tamper-evident bag with a visible receipt. If you are transferring to another flight in a different country, these liquids may be screened again and subject to that country's security rules.

International rules

The rule was introduced in 2006 after security officials in the UK foiled a plot to bomb an aircraft using liquid explosives. Since then, security agencies worldwide have implemented similar restrictions. While the rule is consistent with international regulations, it is not always enforced as stringently outside of the US. For example, some European airports have eliminated the restrictions, and the UK has extended the liquid limit to 2 liters (68 oz) as of June 2024.

The definition of LAGs varies slightly between countries. In the US, the TSA considers frozen liquids to be exempt from the rule, as long as they are completely frozen. Additionally, passengers are allowed to carry some non-compliant liquids, such as prescription medication, breast milk, and baby formula, but these items may be subject to additional screening.

When traveling internationally, it is important to check the specific rules and regulations of your destination country, as some items may be restricted or prohibited. For example, many Islamic countries prohibit or restrict alcohol, and some countries have specific rules about duty-free purchases.

Frequently asked questions