Polycyclic aromatic hydrocarbons (PAH)
Polycyclic aromatic hydrocarbons (PAH)
Polycyclic aromatic hydrocarbons (PAHs) such as benzo[a]pyrene are carcinogenic substances formed by incomplete combustion processes of organic materials (wood, coal, gasoline, oil, tobacco, waste) or in food (grilling, frying, smoking, drying). PAHs are solid, mostly colorless, compounds. They are lipophilic (fat soluble), and are sparingly soluble in water. Currently, about 250 different PAH compounds are known.
In nature, PAHs are formed, for example, by forest fires and steppe fires or volcanic activity. However, higher levels in soil are largely caused by humans. The main sources are industrial processes in mineral oil processing, coal chemistry, metal processing or energy generation. PAHs enter the atmosphere via waste gases and ash and are dispersed through the air. Polycyclic aromatic hydrocarbons are thus present everywhere in the environment, including in soil and surface water. Humans can also ingest PAHs through cigarette and tobacco smoke.
These compounds enter food via environmental contaminants. They are detected in plant foods such as fruits and vegetables. Higher levels are found especially on the surface of large-leafed vegetables. Polycyclic aromatic hydrocarbons are also found in the seabed and are ingested by fish and seafood such as mussels.
PAHs are also produced in industrial food processing, especially heating and drying, and home cooking. PAHs are found in fried, grilled, dried, or smoked foods, as well as fats and oils. Drying and roasting coffee beans and tea leaves can also lead to high levels. Due to dilution with water, PAHs are often no longer detectable in the finished brewed coffee or tea beverage, or are found in very low amounts.
Benzo[a]pyrene was classified as "probably carcinogenic to humans" by the International Agency for Research on Cancer (IARC) in 1987. In 2002, the European Commission's Scientific Committee on Food (SCF) and the Joint FAO/WHO Expert Committee on Food Additives defined 16 PAH compounds that had been shown to be mutagenic and, except for one compound, carcinogenic in animal studies. Consequently, the SCF concluded that these PAHs are also potentially mutagenic and carcinogenic to humans. Therefore, no intake level can be determined for these substances at which there is no health risk.
Situation in Austria
In Commission Regulation (EC) No. 1881/2006 of December 19, 2006, polycyclic aromatic hydrocarbons are uniformly regulated as contaminants in food. The maximum levels are set according to the ALARA principle ("as low as reasonably achievable"). Since September 2012, maximum levels no longer apply to benzo[a]pyrene alone, but also to the sum of PAH4 (benzo[a]pyrene, benzo[a]anthracene, benzo[b]fluoranthene, chrysene). Regulation 1881/2006 has since been amended by several regulations.
Every year, we test numerous foods for their PAH content and submit the results to the European Food Safety Authority (EFSA). Results can be found in the food safety reports as well as in the publications of our focus actions.
Reduction of PAH levels:
- Wash or peel fruits and vegetables, as higher levels are more likely to be measured on the surface.
- When grilling, use oil sparingly or carefully dab off marinade containing oil so that fat from the grilled food does not drip onto the hot embers and burn
- PAH intake can be further reduced by a varied diet with infrequent and moderate consumption of more highly contaminated foods.
An important PAH compound is benzo(a)pyrene, which has been classified as carcinogenic and mutagenic. Since 2002, 16 other PAH compounds have been classified as carcinogenic and mutagenic in food by the European Commission's Scientific Committee on Food (SCF) and the Joint Expert Committee on Food Additives (JECFA).
Until 2008, benzo[a]pyrene was considered the sole marker for the presence and effects of the other PAH compounds in food. Based on new data, an evaluation by EFSA took place in 2008. EFSA concluded that benzo[a]pyrene is no longer suitable as a sole marker and recommends instead a system of four individual PAH substances (PAH4 = benzo[a[pyrene, benzo[a[anthracene, benzo[b[fluoranthene, chrysene).
PAH intake of the Austrian population
Based on test results from 2007-2011 of PAHs in food, we performed an intake estimation for the Austrian population. Overall, a low health risk can be assumed for the population as a whole on the basis of these test results.
Benzo[a]pyrene is ingested most via sausages and smoked freshwater fish products. In children, cocoa and cocoa products also play a role. Women consume an average of 0.43 ng/kg bw/day, men 0.64 ng/kg bw/day, and children 0.89 ng/kg bw/day. For frequent eaters, benzo[a]pyrene intake is 2.57 ng/kg bw/day for women, 3.80 ng/kg bw/day for men, and 3.81 ng/kg bw/day for children.
The population ingests the greatest amounts of PAH4 through canned fish and seafood and smoked freshwater fish products. For children, cocoa and cocoa products again come into play. On average, women consume 1.09 ng/kg bw/day, men 0.88 ng/kg bw/day, and children 2.44 ng/kg bw/day. Considering frequent consumers, the intake for women is 13.94 ng/kg bw/day, for men 19.86 ng/kg bw/day and for children 21.22 ng/kg bw/day.
PAH intake of the European population
EFSA's 2008 assessment of polycyclic aromatic hydrocarbons incorporated consumption data and occurrence data from 16 European Union member states. The benzo[a]pyrene intake of the European population is on average 3.9 ng/kg bw/day. The exposure of frequent eaters is on average 6.5 ng/kg bw/day. The intake of PAH4 is 19.5 ng/kg bw/day on average and 34.5 ng/kg bw/day for frequent eaters. Cereals and cereal products as well as seafood and products thereof have been identified by EFSA as those commodity groups that contribute most to the overall exposure.
Commission Regulation (EU) No. 835/2011 of 19 August 2011 amending Regulation (EC) No. 1881/2006 as regards maximum levels for polycyclic aromatic hydrocarbons in foodstuffs. OJ No. L 215, 20.8.2011, 4-8.
Commission Regulation (EU) 2015/1125 of 10 July 2015 amending Regulation (EC) No 1881/2006 as regards maximum levels of polycyclic aromatic hydrocarbons in katsuobushi (dried skipjack) and in certain smoked Baltic herring.
Commission Regulation (EU) 2015/1933 of 27 October 2015 amending Regulation (EC) No 1881/2006 as regards maximum levels of polycyclic aromatic hydrocarbons in cocoa fiber, banana chips, food supplements, dried herbs and dried spices
Commission Regulation (EU) 2020/1255 of 7 September 2020 amending Regulation (EC) No 1881/2006 as regards maximum levels of polycyclic aromatic hydrocarbons (PAHs) in traditionally smoked meat, traditionally smoked meat products, traditionally smoked fish and traditionally smoked fishery products and setting a maximum level for PAHs in powders from food of plant origin used for the preparation of beverages.
Last updated: 14.02.2022