In an article published on May 5, 2016 in the peer-reviewed journal Food Additives & Contaminants: Part A, Oguzhan Yavuz and colleagues from the Joint Research Centre (JRC) of the European Commission (EC), Ispra, Italy, report on the content of primary aromatic amines (PAAs) in colored paper napkins obtained in stores across Europe.

Some types of PAAs have genotoxic, carcinogenic, and allergenic properties. Sources of PAAs in foodstuffs include printing azo-dyes, azo-pigments, isocyanate based adhesives and monomers. For food contact materials (FCMs) made of paper and board, currently no harmonized legislation exists in the EU. However, there are restrictions on PAAs established by Regulation (EU) No 10/2011 on plastic FCMs, and PAAs of toxicological concern are listed in the REACH Regulation (EC) No 1907/2006. In 2013, the German Federal Institute for Risk Assessment (BfR) published an opinion suggesting that the limit value for PAA release from printed FCMs such as paper napkins and bakery bags should be the same as that set for plastic FCMs, i.e. 10 µg/kg food or food simulant. In addition, BfR suggested setting individual migration limits of 2 µg/kg food or food simulant for known carcinogenic PAAs belonging to categories 1A and 1B of the EU Regulation on Classification, Labelling and Packaging (CLP) of substances and mixtures. An inter-laboratory comparison study published in 2015 showed that this detection limit is analytically feasible.

Yavuz and colleagues analyzed a total of 93 colored paper napkin samples. The napkins, obtained mainly in the Italian, Swiss and Dutch markets, were produced in Germany (19), Italy (16), Slovakia (13), Belgium (10), Poland (7), the Netherlands (3), Switzerland (2), Spain (2), Greece (2), China (1), and Hungary (1); for 17 napkin samples, the country of origin was not known. A multi-analyte method based on ultrahigh pressure liquid chromatography tandem mass spectrometry (UHPLC/MS/MS) was optimized for the analysis of 36 toxicologically relevant PAAs in cold water extracts of colored paper napkins. Extraction was done according to European Committee for Standardization (CEN) standard EN 645. Limit of detection (LOD) of the analytical method for 36 PAAs was in the range of 0.03-1.38 µg/L.

The analysis showed that the extracts from 42 out of 93 colored paper napkins contained at least one PAA at a concentration higher than the LOD. The majority of the samples contained 1-3 PAA, 5 samples contained 5 different PAAs, and two samples contained 8 different PAAs. Of 36 PAAs analyzed, 21 were detected in the range of 0.19-17.6 µg/L, with aniline (CAS 62-53-3) detected most frequently (n=14), followed by 2,4-dimethylaniline (CAS  95-68-1; n=12), o-toluidine (CAS 95-53-4; n=11), 3-amino-4-methoxybenzanilide (CAS 120-35-4; n=9), and o-anisidine (CAS 90-04-0; n=8). The sum of detected PAAs was in the range of 0.19-43 µg/L. 19 samples had PAA concentrations in the range of 0.19-3.0 µg/L; in 7 samples, total PAAs concentration was higher than 10 µg/L.

More than half of the detected PAAs are classified as carcinogens or suspected carcinogens; these PAAs are listed in Table 1. For most of them, levels higher than 2 µg/L were detected in some of the samples. By far the highest content of PAAs was found in red napkins, followed by multi-color, yellow and orange napkins.

Table 1

CLP*
Carc.
Cat.
NameCASSamples with detectionMin-Max range (µg/L)Average range (µg/L)
n% (of 93 total)
1A4-aminobiphenyl92-67-111.10.30.3
benzidine92-87-533.20.2-2.71.6
1B4,4'-diaminodiphenylether101-80-411.12.12.1
4,4'-methylenedianiline101-77-922.20.19-0.190.19
2,4-toluenediamine95-80-722.21.6-2.42
4-chloroaniline106-47-833.20.3-5.92.3
4,4'-methylene-bis-(2-methylaniline)838-88-033.21.6-2.31.8
4-aminoazobenzene60-09-366.50.7-10.34.2
o-anisidine90-04-088.60.7-12.03.3
o-toluidine95-53-41111.80.23-10.92.3
22-aminobiphenyl90-41-511.10.30.3
Aniline62-53-31415.10.3-17.63.1

*Hazard categories for carcinogens in the Classification, Labeling and Packaging (CLP) Regulation (EC 1272/2008): Carcinogen Category 1A: known to have carcinogenic potential for humans, classification largely based on human evidence; Carcinogen Category 1B: presumed to have carcinogenic potential for humans, classification largely based on animal evidence; Carcinogen Category 2: suspected human carcinogens.

Read more

BfR (July 24, 2013). “Primary aromatic amines from printed food contact materials such as napkins or bakery bags.” (pdf)

References

Yavuz, O. et al. (2016). “Determination of primary aromatic amines in cold wáter extract of coloured paper napkin samples by liquid chromatography-tandem mass spectrometry.Food Additives & Contaminants: Part A (published online May 5, 2016).

Merkel, S. et al. (2015). “Inter-laboratory comparison study on the determination of primary aromatic amines in cold water extracts of coloured paper napkins.Food Additives & Contaminants: Part A, 32:1367-1372.

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