Operation-resolved VOC emissions from electronics manufacturing: Implications for ozone formation, toxicity, and...

Conventional mass-based indicators often fail to reflect the environmental and health risks of volatile organic compounds (VOCs). To support risk-oriented management in the electronics manufacturing industry of the Pearl River Delta (PRD), this study investigates the relationship between total VOC (TVOC) mass emissions and their associated ozone formation potential (OFP) and toxicity-weighted concentrations (TWC). OFP and TWC were used as source-oriented metrics to prioritize emission sources based on their intrinsic photochemical reactivity and toxicological hazards. After pre-screening 76 stacks, 26 representative post-treatment stack emissions from 12 facilities were characterized. Although influenced by end-of-pipe treatment processes, these post-treatment profiles accurately reflect the actual chemical signatures released into the atmosphere. VOC source profiles varied significantly across operations: extrusion and adhesive-related processes were dominated by residual monomers, while solvent-use operations emitted more complex mixtures. OFP was driven by a small subset of highly reactive species (e.g., aromatics), and TWC exhibited wide variation, with trace species (e.g., acrolein) contributing disproportionately to toxicity despite their low mass fractions. Statistical analysis revealed a systematic decoupling among emission mass, photochemical reactivity, and toxicological risk. TVOC showed a moderate correlation with OFP (R² = 0.46, p < 0.01) but no significant correlation with TWC (R² < 0.11, p > 0.05). This decoupling underscores the limitations of mass-based controls and emphasizes the need for operation-specific mitigation strategies that prioritize high-impact species. The operation-resolved profiles provide a solid foundation for refining emission inventories and supporting targeted regulatory strategies for risk-oriented VOC management.