Correct answer: 0.25 milligrams of alcohol per liter of exhaled air.

The general limit is 0.25 mg/l in exhaled air or 0.5 g/l in blood. It applies to drivers of legal age who have held their license for at least two years and are not driving a vehicle subject to a lower limit. Novice drivers and those driving trucks over 3,500 kg, buses, taxis, and other transport vehicles have a limit of 0.15 mg/l, while underage drivers have a limit of 0.0. The 0.50 figure refers to blood, in grams per liter.

Real Decreto 1428/2003, de 21 de noviembre, por el que se aprueba el Reglamento General de Circulación · Real Decreto Legislativo 6/2015, de 30 de octubre, por el que se aprueba el texto refundido de la Ley sobre Tráfico, Circulación de Vehículos a Motor y Seguridad Vial