Medical items and baby supplies are the biggest exemption to the liquids rule. Prescription and over the counter medication, liquid formula, breast milk and juice for a small child are allowed in reasonable quantities above 3.4 ounces, as long as you declare them for separate screening. Syringes, CPAP machines, nebulizers and insulin coolers all fly in the cabin.What trips travelers up is documentation abroad and airline paperwork for devices that need power on board. Each item page below gives the security verdict, the quantity rule, and the international note for the countries that treat common US medications as controlled.