Originally Posted by
pseudoswede
Duty-free liquor is excluded from TSA's 100ml rule...
https://www.tsa.gov/travel/security-...g/liquids-ruleInbound International Flights
You may carry duty free liquids in secure, tamper–evident bags, more than 3.4 oz or 100 ml in your carry-on bag if:
- The duty free liquids were purchased internationally and you are traveling to the United States with a connecting flight.
- The liquids are packed in a transparent, secure, tamper-evident bag by the retailer and do not show signs of tampering when presented to TSA for screening.
- The original receipt for the liquids is present and the purchase was made within 48 hours.
The items inside the secure, tamper-evident bags must be screened and cleared. Any item that alarms or is unable to be screened will not be permitted in your carry-on bag. We recommend packing all liquids, gels, and aerosols that are over 3.4 oz or 100 ml in your checked baggage, even if they are in a secure, tamper-evident bag.
It may be too late for original poster's family as already in the air... but exactly as you've stated, it is allowed. But it MUST be in the STEB with the tamper-evident seal with receipt inside. The bag and the bottle inside have to both be transparent. Some duty free locations will ask passengers bound for the US if they need this... others won't be so proactive and it must be requested. Some don't offer it.