Determination of Benzene in Sunblock Employing Static Headspace Sampling

Importance of the Topic

Benzene is a well known carcinogen frequently used in industrial processes and capable of contaminating consumer products. Sunscreen, applied repeatedly over large skin areas, requires stringent monitoring to protect public health and comply with safety limits.

Objectives and Study Overview

This study evaluates static headspace sampling coupled to GC MS to detect and quantify benzene in a range of commercial sunscreens. The goal is to establish a fast, reliable protocol for manufacturers to ensure product safety.

Methodology

Samples of spray and lotion sunscreens were prepared by mixing defined masses with dimethyl sulfoxide and an internal standard. A calibration curve spanning 0.05 to 10 µg/mL was generated. Precision and accuracy were assessed at low and mid calibration points using replicate analyses.

Applied Instrumentation

• Flex Series Autosampler with 2.5 mL headspace syringe and six position incubator agitator at 100 C
• Gas chromatograph equipped with a Rxi-624Sil MS column 30 m x 0.25 mm I D 1.4 um
• Mass spectrometer operating in selective ion monitoring mode for benzene ions

Main Results and Discussion

Calibration exhibited excellent linearity R2 = 0.999 and reproducibility with precision below 3.2 percent RSD. Among tested products, one spray sunscreen sample showed benzene at 3.37 µg/mL, exceeding safety thresholds, while all other lotions and sprays were below detection limits. The method demonstrated sensitivity suitable for routine quality control.

Benefits and Practical Applications

• Rapid screening of volatile carcinogens in complex matrices
• Simple sample preparation compatible with production environments
• Robust performance for regulatory compliance and consumer safety

Future Trends and Opportunities

Advances may include solid phase micro extraction for solvent free sampling, miniaturized portable GC MS for field testing, and multiplexed headspace systems for simultaneous analysis of multiple contaminants.

Conclusion

Static headspace GC MS provides a reliable, accurate approach to detect benzene in sunscreen formulations. Implementing this method supports manufacturers in ensuring product safety and protecting consumers from carcinogenic exposure.

References

1. Valisure Detects High Levels of Known Human Carcinogen Benzene in Sunscreen Products and Requests FDA Actions May 25 2021
2. U S Environmental Protection Agency Benzene Factsheet Retrieved July 1 2021
3. Occupational Safety and Health Administration Benzene Standard 29 CFR 1910 1028 Federal Register September 11 1987