On 9 March 2023, the Court of Justice (Second Chamber) delivered a preliminary ruling about the coordination of two European Union measures against air pollution: the Industrial Emissions Directive and the Ambient Air Quality Directive. Upon assessment, the Court reinforced the mandatory nature of the air quality limit values vis-à-vis possible derogations foreseen in the Industrial Emissions Directive. In this case, both AG Kokott and the Second Chamber affirmed the primacy of the air quality standards. However, this Case Note finds that slightly different reasoning between the AG Opinion and the final Judgment reveals differing underlying approaches. Whilst the AG focuses on air quality plans and leaves more room for discretion to national authorities, the final Judgment anchors the coordination of the two Directives to strict and objective pollution limit values, further strengthening the Ambient Air Quality Directive as an effective instrument of environmental protection litigation.