坐飞机可以带 止咳糖浆 吗？（美国TSA/加拿大CATSA标准）

可以随身：单瓶容器容量不超过100毫升（3.4盎司），且须装入容量不超过1升的透明自封塑料袋中。

允许托运：超过100毫升的大容量液体及日化品可以放入托运行李中托运（须符合气雾剂总量规定）。

Limited to what fits inside a single 1-quart (1-liter) transparent resealable bag in carry-on.

Standard toiletries and liquids conforming to the 3-1-1 rule (containers under 3.4 ounces / 100 ml inside a clear quart bag) require no separate declaration. You simply place the bag in a screening bin. Medically necessary liquids exceeding 3.4 ounces must be verbally declared to checkpoint screeners before inspection.

If liquid containers exceeding 3.4 ounces (100 ml) are detected in carry-on baggage without an infant or medical exemption, screeners will not allow them past security. Travelers must surrender the item for destruction, return outside security to place it in checked luggage, or mail it home.

CATSA: Yes — cough syrup is allowed in carry-on baggage through Canadian security checkpoints. In checked bags: Yes — allowed in checked baggage with proper packaging.