Process-resolved characterization and multi-metric co-control of VOC emissions in pesticide manufacturing

Pesticide manufacturing is a significant source of volatile organic compounds (VOCs), contributing to secondary pollution, climate impacts, and human health risks. However, a lack of process-resolved measurements, reliable emission factors (EFs), and integrated impact assessments limits effective emission control in this sector. Here, full-process measurements of 110 VOC species were conducted in two representative pesticide manufacturing enterprises in China. EFs for 18 pesticide products (10.42-329.73 kg/t) and four emission sources (14-104.65 kg/t) were firstly developed. An emission-weighted method was developed to establish source profiles, revealing that aromatics (38%), OVOCs (21%), and halocarbons (20%) were dominant species. Toluene, dichloromethane, acetone, acetaldehyde, and, chloroform are key contributors. Based on updated EFs, a province-level VOC emission inventory for 2024 was constructed (516.61 Gg), with over 60% of emissions concentrated in four provinces. Without additional controls, emissions are projected to increase to 664.19 Gg in 2030 and 838.37 Gg in 2035. Scenario analysis indicates that fugitive emission control is the most effective single measure, while region-specific strategies can further enhance mitigation efficiency. A multi-metric assessment framework was established to integrate VOC emissions, ozone formation potential (OFP), secondary organic aerosol formation potential (SOAP), ozone depletion potential (ODP), and global warming potential (GWP). It could reveal substantial heterogeneity in mitigation performance. It is shown that "Process control" achieved the highest synergistic benefits, reducing total emission, OFP, SOAP, ODP, and GWP by 36%, 29%, 55%, 53%, and 66%, respectively. These findings provide a robust scientific basis for process-oriented VOC management and targeted mitigation strategies in pesticide manufacturing.