TSA limits aerosols to 3.4 ounces per container in carry-on bags

The TSA (Transportation Security Administration) allows aerosol cans in your carry-on bag only if each container holds 3.4 ounces (100 milliliters) or less. This is the same size limit that applies to all liquids and gels. The total volume of all your aerosols combined cannot exceed 1 quart (roughly 32 ounces), and they must fit in a single clear plastic bag.

Not all aerosols are treated the same. Most common household and personal care aerosols—deodorant, hairspray, sunscreen spray, shaving cream—are allowed under this rule. However, flammable aerosols like lighter fluid, paint, and certain insecticides are banned from both carry-on and checked luggage entirely. Some aerosols, like self-defense sprays, are prohibited in carry-on but may be allowed in checked bags under specific conditions.

The 3.4-ounce limit applies to the container itself, not what you've used from it. A half-empty 5-ounce can still exceeds the limit and cannot go in your carry-on, even though it holds less product.

Key Takeaways

  • Each aerosol container in your carry-on must be 3.4 ounces (100 milliliters) or smaller.
  • All aerosols together must fit in one clear quart-sized plastic bag, the same bag you use for other liquids and gels.
  • Flammable aerosols like paint, lighter fluid, and certain insecticides are banned from both carry-on and checked luggage.
  • Self-defense sprays are prohibited in carry-on bags but may be allowed in checked luggage if they meet specific DOT requirements.
  • A partially used aerosol can still counts as its original container size, so a half-empty 5-ounce can is not permitted in carry-on.

Which aerosols are allowed in carry-on bags

Most personal care and household aerosols fall within TSA rules for carry-on. Deodorant spray, hairspray, body spray, dry shampoo, and sunscreen spray are all permitted as long as each can is 3.4 ounces or smaller. Shaving cream, whipped cream, and cooking spray aerosols also count as allowed items under the same size restriction.

The key is that these products are not classified as flammable by the Department of Transportation. Even though some contain propellants, they are formulated to be safe for air transport when they meet the size and quantity limits. Always check the label on your specific product—if it says "flammable" or "contains flammable gas," it may be restricted.

Aerosols that are completely banned

Certain aerosols cannot travel in either your carry-on or checked bag. Flammable aerosols are the main category: paint, paint thinner, lacquer, varnish, lighter fluid, and fuel are all prohibited. Insecticides labeled as flammable are also banned. Some air fresheners and cleaning products marked as flammable fall into this category as well.

Check your product's label for the word "flammable" or "contains flammable propellant." If you see it, do not pack that item in your luggage at all. The TSA website and your airline's website both list prohibited items, and you can search by product name if you are unsure about something specific.

Self-defense sprays and special restrictions

Pepper spray and similar self-defense aerosols are not allowed in carry-on bags. They are prohibited in the cabin of the aircraft. However, some airlines permit one 2% by mass tear gas self-defense spray in checked luggage only, and only if it is equipped with a safety mechanism to prevent accidental discharge. The container must not exceed 2 ounces (59 milliliters).

Rules for self-defense sprays vary by airline and destination. Some countries and states have their own restrictions on these items. Before packing a self-defense spray in checked luggage, contact your airline directly to confirm their policy. Do not assume that because it is legal in your state, it is allowed on your flight.

How to pack aerosols correctly for carry-on

Place all your aerosols—along with other liquids, gels, and creams—in a single clear plastic bag no larger than 1 quart. This is the standard quart-sized freezer bag you can buy at any grocery store. Each individual container must be 3.4 ounces or smaller. The bag itself should close completely and fit easily in your carry-on.

At security, you will remove this bag and place it in the bin for screening. TSA officers will inspect it to confirm that each container meets the size limit. Aerosols with damaged seals or leaking caps should not be packed—they can damage other items and may be confiscated.

If you are traveling with a full-size aerosol can (larger than 3.4 ounces), pack it in your checked bag instead, provided it is not flammable. Checked baggage has different rules: non-flammable aerosols are generally allowed, but flammable ones are still banned. Your airline will provide specific details about what is permitted in checked luggage.

Aerosols in checked luggage

Non-flammable aerosols larger than 3.4 ounces can go in your checked bag. This includes full-size deodorant, hairspray, and sunscreen spray cans. However, flammable aerosols remain banned from checked luggage—there is no size exception. The cabin and cargo hold of an aircraft have different safety systems, but flammable materials are restricted in both.

Pack aerosols in the center of your checked bag, surrounded by soft items like clothing, to reduce the risk of damage during handling. A damaged aerosol can leak and ruin other belongings. If an aerosol leaks in your checked bag, it may damage the aircraft or injure baggage handlers, so airlines take this seriously.

International flights and different rules

International flights may have stricter rules than domestic U.S. flights. The International Air Transport Association (IATA) sets global standards, but individual countries and airlines can impose additional restrictions. Some countries prohibit aerosols that are allowed in the United States, or limit the quantity you can bring.

Before packing aerosols for an international flight, check your destination country's regulations and your airline's specific policy. What is allowed from New York to London may not be allowed from New York to Mexico City. Your airline's website usually has a prohibited items list for each route, or you can call their customer service to ask about a specific product.

Frequently Asked Questions

Can I pack a full-size deodorant can in my carry-on?

Only if it is 3.4 ounces or smaller. Most full-size deodorant cans are 4 to 6 ounces, so they must go in checked luggage. Look for travel-size or mini aerosol deodorants at drugstores—these are typically 1 to 2 ounces and fit the carry-on limit.

What happens if I accidentally pack a banned aerosol?

TSA officers will find it during screening and confiscate it. You will not be allowed to bring it through security. If you realize before you reach the airport, you can leave it at home or pack it in checked luggage if it is not flammable. Do not try to bring a banned item through security.

Are spray sunscreens allowed in carry-on?

Yes, if the container is 3.4 ounces or smaller. Spray sunscreen is not classified as flammable by the TSA, so it follows the standard liquid and aerosol rules. Pack it in your quart-sized bag with other liquids and gels.

Can I bring hairspray on an international flight?

It depends on your destination and airline. Hairspray is allowed on most U.S. domestic flights and many international routes, but some countries restrict it. Check your airline's website or call them before your trip to confirm the policy for your specific destination.

Do I need to declare aerosols at security?

No special declaration is needed. straightforward place your quart bag with aerosols and other liquids in the security bin when asked. TSA officers will inspect it as part of routine screening. If you have questions about a specific product, you can ask an officer before you go through the scanner.