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Airport & Security 6 min read

TSA Carry-On & Liquid Rules: 3-1-1 Liquids Rule Explained

Navigating TSA security screening efficiently starts with understanding the 3-1-1 liquids rule, prohibited items list, and laptop carry-on guidelines.

Senior Travel Editor & Aviation Specialist

Fact-checked by Sarah Jenkins
Updated September 2026
AI Travel Summary & Overview

Guide Summary & Essential Takeaways

Navigating TSA security screening efficiently starts with understanding the 3-1-1 liquids rule, prohibited items list, and laptop carry-on guidelines.

Key Travel Facts & Insights

  • 3.4 oz (100ml) maximum per container
  • 1 quart-sized clear resealable plastic bag
  • 1 bag per traveler presented separately at security
  • Medications & Infant Formula Exceptions
  • Electronics & Powdered Substances

The 3-1-1 Liquids Rule Demystified

TSA allows travelers to carry liquids, gels, and aerosols in containers of 3.4 ounces (100 milliliters) or smaller. All liquid containers must fit into a single 1-quart clear zip-top bag. Each passenger is allowed one quart bag.

  • 3.4 oz (100ml) maximum per container
  • 1 quart-sized clear resealable plastic bag
  • 1 bag per traveler presented separately at security

Medications & Infant Formula Exceptions

Medically necessary liquids, prescription drugs, baby formula, breast milk, and juice are exempt from the 3-1-1 liquids rule. You must declare these items to TSA officers prior to screening.

Electronics & Powdered Substances

Laptops and electronics larger than a cell phone must be removed from carry-on bags for separate X-ray screening unless in a TSA PreCheck line. Powdered substances over 350ml (12 oz) may require additional inspection.

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Frequently Asked Questions

Are full-size toothpaste tubes allowed in carry-on bags?

No, toothpaste is considered a gel and must be 3.4 ounces (100ml) or smaller to pass through TSA security.

Can I bring solid food through TSA security?

Yes, solid food items like sandwiches, fruit, snacks, and nutrition bars are permitted in carry-on bags.