A method and a system for controlling dust particle emissions from an electrostatic precipitator (1), which has a first and a second bus-section (16, 20), are provided. Dust particle emissions are controlled by observing that a rapping event of the first bus-section (16) is about to be initiated, verifying, before allowing the rapping event of the first bus-section (16) to be initiated, that the second bus-section (20) is ready to receive the dust particles to be released during the rapping event of the first bus-section (16), and then initiating, after verification, the rapping event of the first bus-section (16).