A green GC/FID engineering control to prevent carcinogenic exposure and chemical waste in petrochemical aldehyde monitoring

• Transforms routine aldehyde analysis into a proactive occupational health intervention by eliminating manual titration and hazardous reagents. • Reduces operator exposure to carcinogenic styrene monomer (IARC 2B) by >90% through direct, automated GC/FID injection, aligning with the Hierarchy of Controls. • Validated as analytically equivalent to ASTM titration methods (p > 0.05, Z-score = -0.18), ensuring data integrity without compromising safety. • Leverages α-methylstyrene as an endogenous internal standard with quantified background correction to ensure accuracy while minimizing chemical waste and handling. • Offers a scalable, automatable engineering control strategy to reduce cancer risk in petrochemical laboratories worldwide. Chronic occupational exposure to styrene monomer (SM), a Group 2B carcinogen per IARC, represents a critical environmental and public health concern in petrochemical industries, particularly during routine aldehyde monitoring that requires direct handling of raw SM and toxic reagents (methanol, hydroxylamine, strong acids). To mitigate this dual occupational and environmental hazard, we developed a GC/FID method enabling direct, automated injection of SM samples without wet chemistry. This method specifically quantifies trace aldehydes: benzaldehyde, phenylacetaldehyde, and acetophenone by leveraging α-methylstyrene, an endogenous internal standard with quantified background correction. The method eliminates operator contact with carcinogenic vapors and hazardous reagents. Validation confirmed analytical equivalence to ASTM titration methods (p > 0.05, Z-score = –0.18), with high sensitivity (LOD: 0.04 mg/kg) and high precision (RSD up to 4.7%). Crucially, workflow redesign reduces operator exposure to SM by >90% and cuts chemical waste generation by >90%, aligning with Green Analytical Chemistry and the Hierarchy of Controls. This study demonstrates how analytical innovation can serve as a scalable engineering control to prevent cancer risk and reduce environmental burden in industrial laboratories worldwide.