A Survey of Residual Solvents in Various Inks used in Consumer Product Packaging

Significance of the Topic

The use of printing inks on consumer product packaging, especially for microwaveable and ovenable items, can release residual solvents when heated. Monitoring these volatile organic compounds (VOCs) is crucial for ensuring food safety, regulatory compliance, and consumer protection.

Objectives and Study Overview

This study surveys residual solvents emitted from printing inks on four common packaging types: microwavable popcorn wrappers (outer sleeve, bag top, bag bottom), a microwaveable sandwich crisping sleeve (printed area and seam), individual potato chip bags, and decorative paper baking cups. The goal is to compare static and dynamic headspace sampling combined with GC–MS for VOC identification and quantification.

Methodology

Packaging samples were cut to fit 22 mL headspace vials and analyzed both blank and spiked with an internal standard solution. Static and dynamic headspace techniques were performed using a Teledyne Tekmar HT3 Headspace Analyzer. Volatiles were separated on a Restek Rtx VMS column and detected by a Thermo Focus GC/DSQ II mass spectrometer. Identification utilized the NIST spectral library and confirmation followed EPA Method 8260 calibration standards, reporting concentrations in parts per billion (ppb).

Used Instrumentation

• Teledyne Tekmar HT3 Headspace Analyzer (static and dynamic modes)
• Thermo Focus GC/DSQ II Gas Chromatograph–Mass Spectrometer
• Restek Rtx VMS 20 m, 0.18 mm ID, 1 µm phase environmental column

Main Results and Discussion

Both sampling modes detected a range of VOCs including acetone, t-butanol, 2-butanone, benzene, toluene, xylenes, and other chlorinated solvents. Dynamic headspace generally produced higher ppb values for highly volatile compounds (e.g., acetone ranged from ~75 to 6 653 ppb) compared to static sampling. Distinct VOC profiles emerged for each packaging type, reflecting differences in ink formulation and sample position relative to the heat source.

Benefits and Practical Applications

This approach offers a robust quality-control tool for laboratories to screen packaging inks for residual solvents. It supports compliance with global safety regulations and helps prevent VOC migration into food products.

Future Trends and Applications

• Integration of solid-phase microextraction to enhance sensitivity for trace volatiles
• Real-time in-line headspace monitoring during packaging production
• Expanded non-target screening workflows to detect emerging ink additives and contaminants

Conclusion

Static and dynamic headspace GC–MS analysis using the Teledyne Tekmar HT3 and Thermo Focus GC/DSQ II effectively identifies and quantifies residual solvents in consumer packaging inks. The methods deliver reliable sensitivity and throughput, facilitating regulatory compliance and protecting consumer health.