PAHs in Plant-Based Products: An Underestimated Contamination Risk

Polycyclic aromatic hydrocarbons (PAHs) are formed wherever combustion processes are incomplete. They can enter plant-based products through drying and smoking processes, environmental air contamination, or during processing.

This is not a niche issue, but a parameter that plays a significant role in the quality control of plant-based raw materials and extracts.

Which PAHs Are Relevant?

From a regulatory perspective, the focus is on the so-called PAH4: benzo(a)pyrene, benzo(a)anthracene, benzo(b)fluoranthene, and chrysene.

The European Food Safety Authority (EFSA) has identified these four compounds as particularly critical due to their genotoxic and mutagenic properties and their frequent occurrence in food.

EU Regulation 2023/915 sets binding maximum levels for these compounds, including for dried herbs, spices, and plant-based food supplements.

For a risk-based quality control approach, it is advisable to go beyond this scope. The extended PAH16 panel, recommended by EFSA, includes additional compounds and provides a more comprehensive basis for product evaluation.

Why the Analysis Is Challenging

Plant matrices are analytically complex.

Fats, resins, waxes, and essential oils can interfere with extraction, co-elute with target analytes, and contaminate analytical systems. Highly condensed PAHs tend to adsorb and can be easily lost during sample preparation.

This means that advanced instrumentation alone is not sufficient—sample preparation is critical.

Our Analytical Approach

We have developed a GC-MS/MS method specifically designed for complex plant matrices.

Triple quadrupole technology provides high selectivity, with limits of quantification starting at 0.9 µg/kg. An optimized extraction combined with effective clean-up reduces interferences and ensures reliable recoveries.

For quality assurance, we use matrix-specific sample preparation modules, surrogate standards for process control, and multiple internal standards.

The method covers both PAH4 and PAH16 and can be applied in either a food testing or GMP-regulated context, including plant raw materials, extracts, tinctures, and fatty oils.

Method Validation

The method has been fully validated in accordance with Regulation (EC) No. 333/2007, SANTE/11312/2021 (v2026), and ICH Q2 (R2).

Regulatory-compliant validation documentation and test methods are available for the validated matrix groups.

What This Means in Practice

Plant-based raw materials are inherently variable.

This requires clearly defined sample intake specifications, controlled storage and transport conditions, and appropriate assignment to the correct sample preparation strategy.

Full traceability within the LIMS, documented surrogate recoveries, and reproducible results are standard requirements—not exceptions.