Rapid Microchamber Tests for Screening Chemical Emissions from Car Trim in Accordance with ISO 12219-3

Importance of the Topic

Rapid and reliable measurement of volatile organic compound emissions from car interior materials is essential to ensure cabin air quality and occupant health. The release of VOCs and SVOCs such as benzene, formaldehyde and phthalates from plastics, textiles and sealants has prompted manufacturers to adopt screening methods that minimize turnaround time without sacrificing accuracy.

Objectives and Overview of the Study

This study evaluates a commercial micro-chamber thermal extractor for compliance with ISO 12219-3 screening requirements. Two types of acrylonitrile-butadiene-styrene samples were tested to demonstrate method reproducibility and correlation with larger-scale chamber data. The aim was to confirm that microchamber analysis can provide rapid and representative emissions data in minutes rather than hours.

Methodology

Sample Preparation

• Six small pieces of molded thermoplastic ABS and five irregular molded sections were weighed and measured for surface area or mass.
• Samples were loaded into individual micro-chambers with consistent orientation to ensure uniform exposure.

Sampling Conditions

• Chamber flow: helium at 50 mL/min.
• Equilibration: 20 minutes at 65 °C.
• Collection time: 15 minutes onto dual-bed sorbent tubes of Tenax TA and Carbograph 5TD.

Analysis Technique

• Thermal desorption followed by GC/MS analysis using a volatile-focused capillary column.
• Target compounds were quantified by integrating extracted-ion chromatograms for butadiene (m/z 54) and styrene (m/z 104).

Instrumentation Used

• Markes micro-Chamber/Thermal Extractor with four 114 mL inert-coated chambers.
• Thermal desorption unit with TD100 control for trap heating and purge.
• Dual sorbent tubes packed with Tenax TA and Carbograph 5TD.
• GC/MS system with DB-624 column under constant pressure mode (4 psi).

Main Results and Discussion

• Emission rates for butadiene and styrene showed relative standard deviations between 4.3 % and 7.6 % for area-normalized ABS pieces, indicating high reproducibility.
• Mass-specific emissions from molded sections exhibited an outlier but overall RSD remained below 16.3 %. Excluding the outlier reduced variability to 4.3 %.
• Data correlated strongly with larger chamber and bag method results, validating microchamber performance for rapid screening.

Benefits and Practical Applications

• Screening for quality control and material selection during development of low-emission trim.
• Short analysis cycles enable testing of multiple prototypes or color variants in a single workday.
• Compact design supports in-house monitoring of production uniformity without dedicated large facilities.

Future Trends and Potential Applications

Advancements in sorbent materials may extend the volatility range to heavier SVOCs. Coupling microchambers with real-time detectors could enable continuous monitoring. Integration with digital lab workflows and automated sample handling will streamline high throughput screening in automotive and consumer product industries.

Conclusion

The micro-chamber thermal extractor offers a rapid, reliable and reproducible approach to VOC emission screening in accordance with ISO 12219-3. Its performance closely matches larger chamber methods while reducing sample throughput time from hours to minutes, supporting efficient quality control and product development.

References

• Kim M Presentation to ISO TC 146 SC6 WG13 Kangwon National University Korea 2010 Document No N0087
• Williams G Pharoah M Correlation between the VDA 276 test and microchamber testing PARD Report University of Warwick UK 2009
• Schripp T et al A microscale device for measuring emissions from materials for indoor use Analytical and Bioanalytical Chemistry 2007 387 1907–1919
• Lor M et al Horizontal evaluation method for the implementation of the construction products directive HEMICPD Belgian Science Policy 2010
• ISO 16000-6 Indoor Air Part 6 Determination of volatile organic compounds by thermal desorption and GC/MS
• Wilke O et al Improvement of VOC measurement from floor coverings BAM Federal Institute for Materials Research and Testing 2009