ENGINE EMISSION CONTROL LABEL ZW220, ZW250 EMISSION CONTROL LABEL: ENGINE LABEL (FOR EPA) Emission control label is attached on the cylinder head cover. The following is the sample of a label required for engin emission control information, along with location. EC EMISSION CONTROL LABEL: ENGINE LABEL Emission control label is attached on the cylinder head cover. The following is the sample of a label required for engine emission control information, along with location.