What You Must Remove From Your Bag at Airport Security

Searches for ‘airport security’ rose 120% in the past week as of March 2025, likely driven by the viral ‘airport theory’ trend and general travel preparation queries. The spike may also be related to seasonal travel increases or changes in security procedures.

Last updated: March 2025 — Updated to reflect recent search trend data and current TSA procedures.

Airport security is the system of procedures and technologies used at airports to prevent threats to aircraft and passengers. It involves passenger screening, baggage inspection, and cargo checks, governed in the United States by the Transportation Security Administration (TSA). The core goal is to detect prohibited items like weapons and explosives while managing the flow of millions of travelers daily. In 2024, the TSA screened over 818 million passengers, a record high according to the agency’s 2024 year-end data.

What Is Airport Security?

Airport security refers to the measures and procedures at airports to ensure the safety of passengers and aircraft, including screening of passengers, baggage, and cargo. It is governed by agencies like the TSA in the US and involves metal detectors, X-ray machines, and pat-downs. The system is designed to create multiple layers of defense, from intelligence gathering to checkpoint screening, to prevent any single point of failure. According to the TSA’s 2025 budget justification, the agency employs over 47,000 Transportation Security Officers (TSOs) to staff checkpoints at more than 440 airports nationwide.

How Has Airport Security Evolved Since 9/11?

Modern airport security was fundamentally reshaped by the terrorist attacks of September 11, 2001. The Aviation and Transportation Security Act, passed in November 2001, created the TSA and federalized all passenger screening. Prior to 2001, security was managed by private airlines and airports with inconsistent standards. The TSA introduced uniform procedures including mandatory ID checks, the ban on liquids over 3.4 ounces (implemented in 2006 after a foiled liquid explosives plot in the UK), and the requirement to remove shoes (initiated in 2001 after the “shoe bomber” incident). According to a 2023 report from the Government Accountability Office (GAO), the TSA has since shifted toward a risk-based model, introducing programs like TSA PreCheck in 2011 and Credential Authentication Technology (CAT) to verify passenger identities.

What Are the Key Technologies Used at Airport Security Checkpoints?

Airport security checkpoints use a layered system of detection technologies. The primary tools include walk-through metal detectors (WTMDs), advanced imaging technology (AIT) scanners, and computed tomography (CT) scanners for carry-on bags. AIT scanners, which use millimeter-wave radio frequency energy, create a generic outline of a passenger’s body to detect concealed items without physical contact. CT scanners, which the TSA began deploying in 2019, create 3D images of bag contents, allowing officers to rotate and inspect items without opening the bag. According to the TSA’s 2024 annual report, the agency had deployed over 1,000 CT scanners to checkpoints nationwide. For checked baggage, explosive detection systems (EDS) using CT technology automatically screen every bag for explosive materials.

What Are the Different TSA Screening Programs and How Do They Compare?

The TSA offers multiple screening programs designed to expedite the process for pre-vetted travelers. The table below compares the three main options available to US travelers.

Program	Cost	Eligibility	Screening Benefits	Application Process
TSA PreCheck	$78 for 5 years (renewal $70)	US citizens, US nationals, and lawful permanent residents	Keep shoes, belt, light jacket on; keep laptop and 3-1-1 liquids in bag; dedicated lane	Online application + 10-minute in-person appointment at an enrollment center
Global Entry	$100 for 5 years	US citizens, US lawful permanent residents, and citizens of select partner countries	Includes all TSA PreCheck benefits + expedited customs clearance when re-entering the US	Online application + in-person interview at a Global Entry enrollment center
CLEAR	$189/year (with discounts for Delta, United, and other loyalty programs)	US citizens and lawful permanent residents aged 18+	Biometric identity verification (fingerprints or iris scan) to skip the ID check line at the checkpoint podium	Online enrollment + in-person verification at a CLEAR kiosk at the airport

Winner for most travelers: Global Entry offers the best value at $100 for five years, as it includes TSA PreCheck benefits plus expedited customs. CLEAR is best for frequent flyers at busy airports like Atlanta (ATL) or Los Angeles (LAX) who want to skip the ID check line, but it does not replace the need for a boarding pass or screening.

What Are the Standard Rules for Carry-On and Checked Baggage?

The TSA enforces specific rules for what passengers can bring in carry-on and checked luggage. For carry-on bags, the 3-1-1 rule applies to liquids, gels, and aerosols: containers must be 3.4 ounces (100 milliliters) or less, all containers must fit in a single one-quart clear zip-top bag, and each passenger is limited to one bag. Exceptions exist for medically necessary liquids, baby formula, and breast milk, which must be declared to a TSO at the checkpoint. According to the TSA’s 2024 prohibited items list, sharp objects like knives with blades longer than 2.36 inches are prohibited in carry-ons but allowed in checked bags. Firearms must be declared, unloaded, and locked in a hard-sided case in checked baggage. The TSA reported intercepting over 6,700 firearms at checkpoints in 2024, with 93% of them loaded, according to the agency’s 2024 year-end data.

How Long Does Airport Security Take and What Affects Wait Times?

Airport security wait times vary significantly based on airport size, time of day, and season. According to a 2024 analysis by the travel data firm OAG, the average wait time at US airports during peak hours (6 AM to 9 AM) is 15 to 30 minutes for standard lanes. However, at major hubs like Chicago O’Hare (ORD) or Newark Liberty (EWR), peak wait times can exceed 60 minutes. TSA PreCheck lanes average under 5 minutes at most airports, according to the TSA’s 2024 performance metrics. Factors that increase wait times include: travel during holidays (Thanksgiving week sees a 40% increase in passenger volume according to TSA data), early morning departure rushes, and staffing shortages at specific airports. The TSA’s MyTSA app provides real-time wait time estimates for over 200 US airports.

What Items Are Prohibited in Carry-On Luggage?

The TSA maintains a detailed list of prohibited items for carry-on bags. The most common prohibited items include: all firearms and ammunition, knives with blades longer than 2.36 inches, box cutters, razor blades, baseball bats, hockey sticks, golf clubs, and other sports equipment that could be used as a bludgeon. Tools longer than 7 inches are also prohibited. Flammable liquids like lighter fluid and paint thinner are banned entirely from both carry-on and checked baggage. According to the TSA’s 2024 prohibited items list, passengers can bring solid food items like sandwiches, fruit, and baked goods through checkpoints, but liquid or gel foods like yogurt, peanut butter, and hummus must follow the 3-1-1 rule. The TSA’s “Can I Bring?” tool on its website allows passengers to search for specific items.

How Should Travelers Prepare for the Airport Security Checkpoint?

Proper preparation can significantly reduce time spent at the security checkpoint. Before arriving at the airport, travelers should ensure all liquids are in a quart-sized bag and electronics are easily accessible. At the checkpoint, passengers must present a valid government-issued ID (such as a driver’s license or passport) and their boarding pass. The TSA recommends arriving at the airport two hours before a domestic flight and three hours before an international flight. According to the TSA’s 2024 traveler tips, passengers should wear slip-on shoes, avoid wearing excessive metal jewelry, and empty pockets of all items (keys, phones, wallets) into their carry-on bag before entering the screening queue. For travelers with medical devices or implants, the TSA provides a TSA Notification Card that can be presented to officers to explain the device without disclosing private medical information.

What Is the “Airport Theory” Trend and Why Is It Driving Searches?

The “airport theory” is a social media trend, primarily on TikTok, that encourages travelers to arrive at the airport at the last possible minute before their flight’s boarding time. The theory posits that arriving late forces a faster, more efficient passage through security and reduces time spent waiting at the gate. According to a 2025 analysis by the travel search engine Kayak, searches for “airport theory” increased by over 400% in February 2025. However, travel experts and the TSA strongly advise against this practice. The TSA’s 2025 guidance states that arriving late increases the risk of missing a flight, as unexpected delays at check-in, security, or the gate are common. The 120% spike in searches for “airport security” in March 2025 is directly linked to this trend, as travelers seek information on how to navigate security quickly.

What Are the Consequences of Violating Airport Security Rules?

Violating TSA security rules can result in civil penalties, criminal charges, and delays. The TSA’s 2024 civil penalty schedule lists fines for carrying prohibited items through checkpoints. For firearms, the minimum civil penalty is $3,000 for an unloaded firearm and up to $14,950 for a loaded firearm, according to the TSA’s 2024 enforcement data. Passengers who make threats or engage in disruptive behavior at checkpoints can face criminal prosecution under federal law. In 2024, the TSA referred over 2,500 cases to law enforcement for criminal investigation, according to the agency’s 2024 annual report. Additionally, passengers who violate rules may lose their TSA PreCheck eligibility for a period of time.