Frew liquid transfer involves the acceptance of duty-free liquids, aerosols, and gels purchased from airline or airport retailers in sealed security bags, subject to screening. These items do not count towards carry-on allowance and may be inspected by screening officers, who can re-seal the bags after inspection. Passengers may be required to surrender duty-free purchases under certain circumstances to ensure security. It is essential to ensure the security features on the clear plastic bags before travel to meet international standards.