Polycyclic Aromatic Hydrocarbons (PAHs), also called polyaromatic hydrocarbons, are a large class of organic compounds consisting of two or more fused aromatic (benzene) rings. They are formed as by-products of incomplete combustion of organic matter — such as wood, charcoal, animal fats, coal, and mineral oils — and are released into the environment through industrial processes, vehicle exhaust, and domestic heating. In food, PAHs form primarily during high-temperature processing: smoking, grilling, roasting, and drying over direct heat.
PAHs are of major food safety concern because many compounds in this group are genotoxic and carcinogenic. Benzo(a)pyrene (BaP) is classified by the International Agency for Research on Cancer (IARC) as a Group 1 human carcinogen. The EU regulatory framework specifically monitors benzo(a)pyrene as an individual marker and the PAH4 sum — the combined concentration of benzo(a)pyrene + benz(a)anthracene + benzo(b)fluoranthene + chrysene — as a more comprehensive marker of total PAH contamination in food.
The highest-risk food categories are smoked meats and fish, edible oils and fats (especially coconut oil and oils processed with activated carbon), dried herbs and spices, and cocoa-based products. Testing for PAHs is an essential component of Ovalab’s contaminants testing service.
Analytical Methods
- GC-MS/MS (Gas Chromatography-Tandem Mass Spectrometry) — Primary analytical method for PAH determination in food. Saponification/liquid-liquid extraction or solid-phase extraction (SPE) clean-up precedes GC-MS/MS analysis. Provides high sensitivity (detection limits <0.1 µg/kg) and selectivity for individual PAH compounds. Preferred for complex matrices.
- HPLC-FLD (High-Performance Liquid Chromatography with Fluorescence Detection) — Alternative method exploiting the strong fluorescence of PAH compounds. Provides good sensitivity for the PAH4 compounds and is particularly useful for oils and fats. Less prone to matrix interferences than HPLC-UV.
- GC-FID (Gas Chromatography with Flame Ionization Detection) — Less selective than GC-MS but faster and simpler. Primarily used for screening purposes in relatively uncomplex matrices. Positive results require GC-MS confirmation.
- Sample Preparation: Saponification + SPE/GPC Clean-up — For fatty matrices (oils, smoked products), alkaline saponification breaks down lipids before SPE or gel permeation chromatography (GPC) clean-up to remove matrix co-extractives. Clean extracts are critical for reliable PAH quantification at regulatory limits.
EU Regulatory Framework
Maximum levels for PAHs in food are set by Regulation (EU) 2023/915 (Annex I, Section 5). The EU regulates two PAH markers: benzo(a)pyrene (BaP) individually and the PAH4 sum (benzo(a)pyrene + benz(a)anthracene + benzo(b)fluoranthene + chrysene). Maximum levels:
| Food product | Benzo(a)pyrene max. (µg/kg) | PAH4 sum max. (µg/kg) |
|---|---|---|
| Smoked meats and meat products | 2.0 | 12.0 |
| Smoked fish and fishery products | 2.0 | 12.0 |
| Smoked molluscs | 6.0 | 35.0 |
| Oils and fats (most) | 2.0 | 10.0 |
| Coconut oil | 2.0 | 20.0 |
| Cocoa beans and cocoa-derived products | 5.0 | 30.0 |
| Dried herbs and spices; plant powders for beverages | 10.0 | 50.0 |
| Banana chips | 2.0 | 20.0 |
| Baby food and infant formula | 1.0 | 1.0 |
| Traditionally smoked meats/fish (national derogation*) | 5.0 | 30.0 |
* The higher derogation limits apply to specific traditional smoked products in certain EU Member States (Ireland, Croatia, Cyprus, Spain, Poland, Portugal, Latvia, Slovakia, Finland, and Sweden) that are produced and sold domestically.
Analytical methods must comply with the performance criteria in Commission Regulation (EU) 836/2011, which sets method performance criteria for PAH in food. All official control testing must be performed by ISO/IEC 17025 accredited laboratories.
Frequently Asked Questions
What are PAH4 compounds and why does the EU regulate them?
The PAH4 sum is the combined concentration of four specific polycyclic aromatic hydrocarbons: benzo(a)pyrene, benz(a)anthracene, benzo(b)fluoranthene, and chrysene. EFSA identified PAH4 as a more reliable indicator of total PAH contamination and genotoxic carcinogenic potency than benzo(a)pyrene alone. The EU therefore requires both markers to be measured: if either the individual BaP limit or the PAH4 sum limit is exceeded, the food is non-compliant under Regulation (EU) 2023/915.
Which foods are most at risk for PAH contamination?
The highest-risk food categories are smoked meats and fish (direct smoke contact), grilled and charbroiled meats (fat dripping onto heat source), edible oils and fats (especially poorly refined coconut oil and oils treated with contaminated activated carbon), dried herbs and spices (drying over open flame), and cocoa products (roasting). Baby foods receive the strictest limit (1 µg/kg for both BaP and PAH4 sum) due to the vulnerability of infants to genotoxic compounds.
How can PAH contamination in smoked food be reduced?
PAH formation in smoked foods can be minimized through: (1) controlling smoking temperature (keeping it below 400°C to limit PAH formation); (2) using indirect smoking methods (smoke generator separate from the product); (3) filtering smoke to remove particulate PAHs; (4) maintaining adequate distance between the heat source and the food product; and (5) using smoke condensates (liquid smoke) rather than direct smoke application. Regulatory compliance requires post-processing testing to verify that limits in Regulation (EU) 2023/915 are met.
What analytical method is used for PAH testing in food?
GC-MS/MS (Gas Chromatography-Tandem Mass Spectrometry) is the preferred method for PAH determination in complex food matrices, providing high sensitivity and selectivity. HPLC with fluorescence detection (HPLC-FLD) is an alternative particularly suited to oils. Sample preparation typically involves saponification (for fatty matrices) followed by SPE or GPC clean-up. Method performance criteria are specified in Commission Regulation (EU) 836/2011. Official testing must be performed by ISO/IEC 17025 accredited laboratories.
Do PAH limits apply to barbecued food in restaurants?
EU maximum levels in Regulation (EU) 2023/915 apply to food products placed on the market (commercially produced and sold). Home-prepared or restaurant-prepared grilled/barbecued food is not directly subject to these specific maximum levels. However, food business operators (restaurants, caterers) are subject to general food safety obligations under Regulation (EC) No 178/2002 and must not supply unsafe food. There is no specific EU enforcement mechanism for PAHs in freshly prepared restaurant food, but food safety guidance recommends proper charbroiling practices to minimize consumer exposure.