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Characterization of plastic packaging additives: Food contact, stability and toxicity
⁎Corresponding author. Tel.: +216 22225011. meriemlahimer@yahoo.fr (Meriem Cherif Lahimer)
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Received: ,
Accepted: ,
This article was originally published by Elsevier and was migrated to Scientific Scholar after the change of Publisher.
Peer review under responsibility of King Saud University.
Abstract
Plastic additives are analyzed by spectrometric (FTIR, ICP-AES) and chromatographic (GC/MS, HPLC) methods in order to define their stability, purity and toxicity. All findings relate to the compounds identified in our packaging and their effect on human health. We wanted to show that some additives contain heavy metals (lead, cobalt, nickel, copper, etc.), highly toxic phtalates (Dibutyl phtalate or DBP) and contaminants (Non-intentionally added substances: NIAS, degradation products). Some additives used are even carcinogenic or tumorigenic.
Keywords
Antioxidants
Endocrine disruptors
Heavy metals
Phtalates
Spectrometry
NIAS
1 Introduction
Eighty percent of plastics in the world are thermoplastics. The most commonly used ones in food packaging industry are usually polystyrene, polyethylene, polyvinyl chloride, etc. (Reyne, 1991). Additives are introduced in polymers in order to improve the physical (mechanical, thermal, etc.) and chemical properties of the packaging (Reyne, 1991; Galotto et al., 2011a): plasticizers are used [3] (Saint-Laurent and Rhainds, 2004), antioxidants (Bart, 2001; PIRA, 2003; Arias et al., 2009; Garrido-Lopez and Tena, 2005; Zhou et al., 1999; Garrido-Lopez et al., 2007), anti-UV (Garrido-Lopez and Tena, 2005), etc.
However, it has been reported that these adjuvants may contain compounds with adverse effects on human health and environment (Grosclaude, 1999; Lacaze, 1993).
In this context and after an initial identification of our packaging and additives by Fourier transform infrared spectroscopy (FTIR), we proceed to the preliminary determination of heavy metals in these additives by Inductively coupled plasma-Atomic emission spectrometry (ICP-AES). This technique is concurrent with the atomic absorption (AAS), the element mass spectrometry (ICP-MS) (Rouessac and Rouessac, 2009; Mendham et al., 2006), etc. Then, to estimate the composition of organic substances in packaging, a full range of commercial additives and packaging extracts are characterized by Gas chromatography coupled with mass spectrometry (GC/MS). Studies describe several thermal methods for introducing polymers in the chromatographic column: thermal desorption, thermogravimetry (TGA), degradation in a tubular oven, pyrolysis (PY) (Bart, 2001; Mortaigne, 1996), etc.
These techniques have many advantages: high sensitivity, no risk of contamination (little handling), no interference from the solvent and respect of the environment (no solvent) (Bart, 2001).
However, they may also be quite costly and sometimes require a fairly laborious work (ex: the tube oven). So we choose solvent extraction that allows an easy analysis of the extracted products and a good separation of polymers and additives. Many GC/MS protocols are described in the literature to identify antioxidants, UV stabilizers, plasticizers and other plastic additives (Sanches Silva et al., 2006; Coulier et al., 2007; Burman et al., 2005; Espert et al., 2005). In our case, the analysis reveals the presence of a phosphite antioxidant “Irgafos 168” in several plastic packaging. Furthermore, ICP results show levels of Copper and Nickel important for this additive. So we quantify this additive in plastic packaging by High-performance liquid chromatography (HPLC) using an internal standard.
2 Materials
Plastic packagings studied are shown in Table 1. The additives subjected to analysis are phenolic antioxidants (Hostanox O3 P, Hostanox O10 P, Hostanox O16), phosphite antioxidants (Hostanox PAR 24), mixtures of antioxidant (Hostanox Blend), UV stabilizer or “anti-UV” (Hostavin N20P) and antistatic agents (Hostastat FA38P, Hostastat FE2P) (see Table 2). Some antioxidants, anti-UV and antistatic molecules are given in Figs. 1 and 2.
| Manufacture (Entse) and manufactured products | Sample | Type |
|---|---|---|
| Entse A: various food packaging |
Ech 1 | LDPE granules used in the manufacture of flexible plugs |
| Ech 2 | PP granules used in the manufacture of chamia (=almond and nougat paste) packaging | |
| Entse B: food bags |
Ech 3 | LDPE granules used in the manufacture of meat and fish bags |
| Entse C: various food packaging |
Ech 4 | Transparent polystyrene box meals |
| Ech 5 | White polystyrene box meals | |
| Entse D: polystyrene food packaging |
Ech 6 | White polystyrene tray |
| Entse E: polystyrene food packaging |
Ech 7 | White polystyrene plate for dessert |
| Ech 8 | White polystyrene cup | |
| Entse F: various food packaging |
Ech 9 | HDPE yoghurt pot |
| Entse G: polypropylene food packaging |
Ech 10 | PP granules used in the manufacture of oil packaging |
| Ech 11 | Chips from the production of oil packaging: recycled into non-food products (cleaning products, etc.) | |
| Entse H: HDPE caps: injected and blown |
Ech 12 | HDPE plug |
| Ech 13 | HDPE plug | |
| Entse I: HDPE and LDPE bags: extrusion/blow |
Ech 14 | Bag for meat |
| Entse J: yoghurt pot |
Ech 15 | Yoghurt pot |
| Entse K: yoghurt pot | Ech 16 | Yoghurt pot |
| Entse L: plastic packaging films |
Ech 17 | Film for tea |
| Entse M: plastic packaging films |
Ech 18 | Film for couscous |
| Entse N: PSE trays |
Ech 19 | PSE tray for meat |
| Ech 20 | PSE tray for meat |
| Sample | Trade name et CAS number | Formula | Type | Melting range (MR) or solidification point (SP) (°C) |
|---|---|---|---|---|
| Add 1 | Hostanox O3 P CAS No. 32509-66-3 (powder) |
Bis[3,3-bis-(4′-hydroxy-3′-tert-butyl-phenyl) butanoicacid] glycol ester | Phenolic antioxidant | 167–171 (MR) |
| Add 2 | Hostanox PAR 24 P (ou Irgafos 168) CAS No. 31570-04-4 (powder) |
Tris(2,4-di-tert-butylphenyl) phosphate | Phosphite antioxidant | 181–187 (MR) |
| Add 3 | Hostanox PAR 24 FF CAS No. 31570-04-4 (poudre) |
Tris(2,4-di-tert-butylphenyl) phosphate | Phosphite antioxidant | 183–187 (MR) |
| Add 4 | Hostanox 016 P (ou Irganox 1076) CAS No. 2082-79-3 (powder) |
Octadecyl-3,5-di-tert-butyl-4-hydroxyhydrocinnamate | Phenolic antioxidant | 50–52 (MR) |
| Add 5 | Hostanox 03 Pills CAS No. 32509-66-3 |
Bis[3,3-bis-(4′-hydroxy-3′-tert-butyl-phenyl) butanoicacid] glycol ester | Phenolic antioxidant | 167–171 (MR) |
| Add 6a | Hostanox SE 10 GR CAS No. 2500-88-1 |
Distearyl-disulfide | Antioxidant: sulfur containing co-stabilizer | 58–59 (MR) |
| Add 7 | Hostanox Blend M 101 P = Hostanox PAR 24 P (Add 2) + Hostanox 010 P (Add 10) | See Add 2 and Add 10 formula | See Add 2 and Add 10 | |
| Add 8 | Hostanox SE 4 FL CAS No. 693-36-7 |
Distearyl-3,3′-thiodipropionate | Antioxidant: sulphur containing co-stabilizer | 63–68 (MR) |
| Add 9a | Hostanox OSP 1 MicroPills CAS No. 36339-47-6 |
Tris [2-tert-butyl-4-thio (2′-methyl-4′-hydroxy-5′-tert-butyl)-phenyl-5- methyl] phenylphosphite | Phosphite antioxidant | >105 (MR) |
| Add 10 | Hostanox 010 P CAS No. 6683-19-8 (poudre) |
Tetrakis [methylene(3,5-di-tert-butyl-4 -Hydroxyhydrocin-namate)] methan | Phenolic antioxidant | 110–125 (MR) |
| Add 11 | Hostanox 010 FF CAS No. 6683-19-8 |
Tetrakis-(methylene-(3,5-di-(tert) butyl-4-hydrocinnamate))methane | Phenolic antioxidant | 110–125 (MR) |
| Add 12 | Hostanox 016 FF (ou Irganox 1076) CAS No. 2082-79-3 (poudre) |
Octadecyl-3,5-di-tert-butyl-4-hydroxyhydrocinnamate | Phenolic antioxidant | 49–54 (MR) |
| Add 13a | Hostavin N24 liq (HALS: Hindered amine) CAS No. 85099-51-0 + 85099-50-9 (mélange) |
Mixture of 2,2,4,4-tetramethyl-20-(ß-myristyl-oxycarbonyl)-ethyl-7-oxa-3,20-diaza-dispiro-[5.1.11.2]-heneicosanon-21 and 2,2,4,4-tetramethyl-20-(ß-lauryl-oxycarbonyl)-ethyl-7-oxa-3,20-diaza-dispiro-(5,1,11,2)-heneicosanon-21 | Anti-UV | 16 (SP) |
| Add 14 | Hostavin Aro 8P CAS No. 1843-05-6 |
2-Hydroxy-4-noctyoxybenzophenone | Anti-UV | 48 (MR) |
| Add 15 | Hostavin Aro 8 GR CAS No. 1843-05-6 |
2-Hydroxy-4-noctyoxybenzophenone | Anti-UV | 48 (MR) |
| Add 16a | Hostavin N20 P CAS No. 64338-16-5 |
2,2,4,4-Tetramethyl-7-oxa-3,20-diaza-dispiro-[5.1.11.2]-heneicosan-21-o | Anti-UV | 230 (MR) |
| Add 17 | Hostastat FE 2P CAS No. 31566-31-1 |
Glycerol monostearate | Antistatic | 60 (MR) |
| Add 18 | Hostastat FE 20 liq CAS No. 85029-63-6 |
Fatty acid ester | Antistatic | 19 (SP) |
| Add 19 | Hostastat FA 38 P (powder) CAS No. 61791-44-4 and 1592-23-0 (mixture) |
Mixture of N,N-bis-(2-hydroxy-ethyl)-alkyl-(C14-C18)-amines (56%) and Calcium Stearate (44%) | Antistatic | 97 (MR) |
| Add 20 | Hostastat FA 14 liq CAS No. 99241-69-7 |
Ethoxylated alkylamine | Antistatic | ⩽5 (SP) |
3 Method
3.1 Experimental protocols
3.1.1 Identification of packaging and commercial additives by infrared spectrometry
FTIR spectrometry (AVATAR, OMNI-SEMPLER 360) is used to identify packaging and commercial additives.
The plastics are directly cut in the package and then analyzed. The spectra obtained are compared to a specialized database (Postaire, 1991).
In general, the percentage of additives added to plastics is very low and often under 3% (DGCCRF, 2009). They almost do not interfere in the infrared profile of polymers. The spectrum obtained is similar to that of pure resin (Postaire, 1991).
Commercial additive powder is homogenized in a mortar with 1% KBr for spectrometry (similar to the inks additives procedure (Vila et al., 2007; Silverstein et al., 2004)).
3.1.2 Extraction of additives from plastic packaging for GC/MS analysis
The additives are extracted from the packaging in the liquid phase by dissolution and re-precipitation of the polymer (Bart, 2001) using the appropriate solvent: toluene/methanol (1:1) for polyolefin and chloroform/methanol (1:1) for polystyrene. As recommended by Mortaigne (1996), we use a solvent which allows a significant swelling of macromolecules. The extract is then filtered and concentrated on a rotary evaporator (70–80 °C at 150 tr/min). Additives are then injected into the GC/MS column.
3.1.3 Mineralization of commercial additives for ICP analysis
It takes 0.5 grams of solid additive. We add 5 ml of HNO3. The solution remains 24 hours at rest and is evaporated by adding 5 ml of HNO3. This step is repeated twice. Finally the whole is transferred in a 50 ml flask which is completed with distilled water.
3.2 Analytical methods
3.2.1 The heavy metals content of additives
The heavy metals content of plastics extracts is given by a JY ULTIMA atomic emission spectrometer (ICP-AES) [120–800 nm]. The operating conditions are presented in Table 3.
| Plasma observation | Radial |
|---|---|
| Frequency | 40.68 MHz |
| Control of the gas flow rates | Computer |
| Control of the peristaltic pump (sample and drain) | Computer |
| Cooling | Air |
| Plasma gas flow | 12 l/min |
| Auxiliary gas flow | 0 l/min |
| Sheath gas flow | 0.2 l/min |
| Nebulization gas flow | 0.9 l/min |
| Nebulization gas pressure | 2.8 bars |
| Sample flow | 1 ml/min |
3.2.2 The additives identification by GC–MS
Gas chromatography (Agilent 6890) coupled with a mass spectrometer type quadrupole (Agilent 5973) identifies certain commercial additives (in methanol) and those present in the extracts obtained. The column used is of type HP 5 MS (copolymer of 5% diphenyl and 95% dimethyl siloxane) with dimensions 30 × 0.25 mm and 0.25 μm particle size. Two oven temperature programs are implemented in Table 4.
| Samples | Protocol 1 | Protocol 2 |
|---|---|---|
| Commercial additives | Extract | |
| Injector temperature | 300 °C | 300 °C |
| Injection volume | 1 μl | 1 μl |
| Flow rate of carrier gas (helium) | 1.5 mL min−1 | 1.5 mL min−1 |
| Initial temperature | 80 °C; (1 min) | 150 °C; (3 min) |
| Final temperature | 290 °C; Compensate for 10 min at 290 °C | 320 °C; Compensate for 20 min at 320 °C |
| Ramp | 10 °C/min | 10 °C/min |
| Time analysis | 32 min | 40 min |
3.2.3 Quantitative analysis by HPLC of Irgafos 168 in packaging
We have quantified the antioxidant Irgafos 168 in four plastic packaging using an internal standard (PIRA, 2003; Lindsay, 1992; Rosset et al., 1991) which is often a counterpart of analyte (Rosset et al., 1991). In our case, we have used the antioxidant Irganox 1040 (Hostanox 010 P).
There are several techniques for extracting the additive from its matrix. Examples include the Soxhlet and ultrasonic extractions. There are also those by supercritical fluid (SFE) (Arias et al., 2009; Zhou et al., 1999; Pinto, 1997), fluid or pressurized liquid (PFE or PLE) (Garrido-Lopez and Tena, 2005; Garrido-Lopez et al., 2007), or microwave-assisted extraction (MAE) (Arias et al., 2009).
In our study, the antioxidant is extracted from its support (polyolefin or polystyrene) by total dissolution of the polymer in toluene (case of polyolefins) or in chloroform (case of polystyrene) and by precipitating it with methanol. We have followed a traditional reflux protocol (PIRA, 2003; Arias et al., 2009). Arias et al. (2009) have shown that the extraction of Irgafos 168 by toluene/methanol (volume ratio; 1:1) was more appropriate than by xylene/methanol (volume ratio; 1:1).
So we have first prepared solutions of Irgafos 168 “IRG 168” (1000 mg/l), internal standard Hostanox 010 P “010 P” (500 mg/l) and standards (Table 5). The internal standard “O10 P” has been added during the plastic dissolution. The methanol (20 ml) has been then used to precipitate the plastic and to maintain only the additives in solution. The supernatant containing the additives has been filtered and injected into the column.
| Standard solution No. | 0 | 1 | 2 | 3 | 4 | 5 |
| Internal standard volume (V010 P en ml) | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 | 0.1 |
| Additive solution volume (Vi en μl) | 0 | 50 | 100 | 500 | 1000 | 1500 |
| Sample final concentration (Cf en mg/l) | 0 | 2.5 | 5 | 25 | 50 | 75 |
3.3 Results and discussions
3.3.1 The polymers and additives identification by FTIR
Most packages analyzed are based on polyolefin (polyethylene, polypropylene) and polystyrene. Infrared spectra of some samples are shown in Fig. 3. The FTIR characterization of commercial additives is given in Table 6. Some spectra of the molecules identified are shown in Fig. 4. Most additives identified have a structure similar to that indicated by the supplier (Ex: Add 7: Irganox B215 (Ciba® IRGANOX® B 215)). Others have structures close to the commercial molecule (Add 1, 16, 17). For example, the FTIR analysis of Add 1 identifies a molecule close to the Hostanox O3P (commercial molecule): these two molecules belong to the same family of the phenolic antioxidant. The molecule identified is an Agerite superlite (mixture of polybutylated bisphenol A). It is often used as a stabilizer in plastic packaging (regulatory: FDA 21 CFR 175.105, 177.2600) (Ash, 2004). But it is not in the positive list (Regulation (EU) No. 10/2011 of the Commission of 14 January 2011).
| Sample | Trade name | FTIR identification |
|---|---|---|
| Add 1 | Hostanox O3 P CAS No. 32509-66-3 (powder) |
Agerite superliteb (mixture of polybutylated bisphenol A) |
| Add 2 | Hostanox PAR 24 P (Irgafos 168) | Irgafos 168a |
| Add 3 | Hostanox PAR 24 FF (Irgafos 168) CAS No. 31570-04-4 (powder) |
Irgafos 168a |
| Add 4 | Hostanox 016 P CAS No. 2082-79-3 (powder) |
UCAR cyracure UVR – 6110c (cycloaliphatic epoxy resin) |
| Add 5 | Hostanox 03 Pills | Parlon S-125c (elastomer chlorinated) |
| Add 6 | Hostanox SE 10 GR (fat) | Conoco 736 wax (paraffin wax)c |
| Add 7 | Hostanox Blend M 101 P (ou Irganox B215) | Irganox B215a |
| Add 8 | Hostanox SE 4 FL | Poly(vinyl)stearate (a wax-like polymer of vinyl stearate)c |
| Add 9 | Hostanox OSP 1 MicroPills | Hostanox VP OSP1a (antioxidant) |
| Add 10 | Hostanox 010 P (Irganox 1010) CAS No. 6683-19-8 (poudre) |
Irganox 1010a |
| Add 11 | Hostanox 010 FF (Irganox 1010) | Irganox 1010a |
| Add 12 | Hostanox 016 FF CAS No. 2082-79-3 (powder) |
Poly(lauryl acrylate) ou octadecyl acrylate homopolymerc |
| Add 13 | Hostavin N24 liq (liquid) | Pentalyn 261 ou refined tall oil (monomer natural oil = rosin oil)c |
| Add 14 | Hostavin Aro 8P (Cyasorb UV-531) | Cyasorb UV-531a (ou Hostavin Aro 8, Octabenzone): additive stabilizer |
| Add 15 | Hostavin Aro 8 GR (Cyasorb UV-531) | Cyasorb UV-531a (ou Hostavin Aro 8, Octabenzone): additive stabilizer |
| Add 16d | Hostavin N20 P | Cyasorb UV-3604b (Hindered amine light stabilizer) |
| Add 17d | Hostastat FE 2P (glycerol monostearate) | Kessco ethylene glycol monostearateb (glycol stearate): additive plasticizer |
| Add 19 | Hostastat FA 38 P (powder) | Conoco 736 wax (paraffin wax)c |
Some additives only (Add 4, 5, 6, 8, 12, 13) give results far from commercial data. It appears that in this case the FTIR spectrum is more that of a resin (Add 4), wax (Add 6, 8, 19), oil (Add 13), elastomer (Add 5) or homopolymer (Add 12) to which the additive is mixed. The commercial product is not always pure. The additives in the form of a fatty or liquid product are usually mixed with oils or waxes based on paraffin or rosin (Add 6, 13, 19). It should be noted that none of these waxes or resins appear in the positive list for food contact (Regulation (EU) No. 10/2011 of the Commission of 14 January 2011).
3.3.2 The additives heavy metals content
Table 7 presents the commercial additives heavy metals content.
| Elément (ppm) | Additifs clariant | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Phenolic antioxidants | Phosphite anti-oxidant | Anti-oxidant Blenda | Anti-UV | Antistatics | |||||
| Add 1 | Add 10 | Add 11 | Add 12 | Add 3 | Add 7 | Add 16 | Add 17 | Add 19 | |
| Ni | 5.43 | 2.08 | 4.32 | 6 | 3 | 7.3 | 1.46 | 2.29 | 16.42 |
| Cd | 0.53 | 0.57 | 0.60 | <0.05 | <0.05 | 0.81 | 0.46 | 0.56 | 0.57 |
| Co | 0.85 | 0.78 | 0.79 | <0.1 | <0.1 | 0.87 | 0.70 | 0.68 | 0.83 |
| Cu | 0.33 | 0.49 | 1.02 | 13 | 8 | 0.95 | 0.26 | 0.77 | 1.35 |
| Pb | <0.10 | <0.10 | <0.10 | 3 | <0.1 | <0.10 | <0.10 | <0.10 | <0.10 |
| Mn | 2.00 | 1.65 | 2.04 | 0.87 | 0.89 | 2.01 | 1.02 | 1.69 | 5.61 |
| Cr | 5.20 | 1.43 | 5.39 | 2 | 2 | 3.56 | 1.83 | 2.61 | 24.68 |
| Zn | 70.72 | 71.08 | 84.80 | 48 | 17 | 102.45 | 67.58 | 83.44 | 73.48 |
| Fe | 67.83 | 42.25 | 65.68 | 10 | 13 | 58.47 | 28.10 | 57.23 | 93.15 |
3.3.2.1 The antioxidants
3.3.2.1.1 The phenolic antioxidants
Hostanox O16FF (Add 12) is the additive that has the highest levels of lead and copper. Although antioxidants have been used and studied for over 50 years, we pay attention to stabilizers loaded with heavy metals, particularly lead. The gradual replacement of lead with cadmium-zinc is strongly encouraged (Houtmeyers, 2006). The blend stabilizer responds to this feature. Its lead content is very low and its Cadmium and Zinc content is much stronger than the other additives studied.
Hostanox O10 P and O10FF (Add 10 et Add 11) have a significant cobalt content (0.78 ppm for the O10P and 0.79 ppm for the O10FF), especially if the specific migration of this metal is limited to 0.1 ppm.
The additives Hostanox O 10 and Hostanox O 16 have the labels R 53 “May cause long-term adverse effects in the aquatic environment” and S 61 “Avoid release to the environment” (Pigments & Additives Division - Clariant, 2006). 53 “May cause long-term adverse effects in the aquatic environment” and S 61 “Avoid release to the environment”.
The Hostanox O3 P (Add 1) does not require labeling (Pigments & Additives Division – Clariant, 2006). However, its Cobalt content remains relatively high. This stabilizer is used for specific applications (Pigments & Additives Division – Clariant, 2006).
3.3.2.1.2 The phosphite antioxidant: Hostanox 24FF (Add 3)
This is the additive studied that contains the least of toxic metals (lead, cobalt, cadmium) and less toxic metals (zinc, iron, manganese). However, its significant levels of nickel and copper can explain the label assigned to it: R 52 “Harmful to aquatic organism”, R 53 “May cause long-term adverse effects in the aquatic environment” and S 61 “Avoid release to the environment” (Pigments & Additives Division – Clariant, 2006).
3.3.2.1.3 The antioxidant “Blend”: Hostanox Blend M 101P (Add 7)
This stabilizer has high levels of Nobalt (highly toxic), and nickel. Its zinc concentration is also very high compared to other additives tested. But zinc is not very toxic, provided it is below the migration limit.
3.3.2.2 The anti-UV (Hostavin N 20)
Hostavin N 20 requires no warning label against risks (Polymer additives for the plastics industry, Overview – Clariant, 2010). This additive is also the least loaded with Nickel, Copper and Chromium and its lead content is quite low. However, it has not been approved for food contact packaging (Polymer additives for the plastics industry, Overview – Clariant, 2010). This may be due to its significant concentrations of cadmium and cobalt.
3.3.2.3 The antistic agents: Hostastat FE 2 (Add 17) and Hostastat FA 38 (Add 19)
Hostastat FE 2 does not have high levels of heavy metals. It is also not a hazardous substance (Pigments & Additives Division – Clariant, 2006).
However, Hostastat FA 38 is the most highly concentrated in nickel, manganese, chromium and iron. Furthermore, the concentration of cobalt is the most important of the list and the cadmium content is quite high. Its labels are R38 “Irritating to skin” and R41 “Risk of serious damage to eyes” (Antistatic agents – Clariant, 2010).
3.3.3 The additive identification by GC/MS
The mass spectra of the Octabenzone molecule is shown in Fig. 5.
3.3.3.1 The commercial additives
The commercial additives identified by GC/MS are listed in Table 8. Among the eight samples analyzed, only two molecules correspond to the commercial molecules (supplier data). These are the anti-UV Add 14 and Add 16. One of them is based on benzophenone. These compounds are fairly stable. Six other samples have structures deriving from the commercial molecule: the antioxidants Add 1, 3, 7, 10, 12 and the antistatic Add 17. Carette (1993) have shown that they are usually degradation products obtained by chain scission. It is always reported that antioxidants are highly sensitive to hydrolysis, heat, etc. An example of degradation products identified by GC/MS is presented below:
| Sample | Trade name | GC/MS identification |
|---|---|---|
| Add 1 | Hostanox O3 P CAS No. 32509-66-3 (powder) = Bis[3,3-bis-(4′-hydroxy-3′-tert-butyl-phenyl) butanoicacid] glycol estera (LMS = 6 mg/kg) |
2,6-Di-tert-butyl-4-(2,4-dimethylbenzyl)phenolb CAS No. 203786-39-4 |
| Add 3 | Hostanox PAR 24 FF a (ou Irgafos 168) CAS No. 31570-04-4 (powder) = Tris(2,4-di-tert-butylphenyl) phosphite |
Diethyl phosphateb CAS No. 598-02-7 |
| Phenol, 2,4-bis(1,1-dimethylethyl)-b CAS No. 96-76-4 |
||
| Phenol, 2,4,6-tris(1,1-dimethylethyl)-b CAS No. 732-26-3 |
||
| Add 7 | Hostanox Blend M 101 P = Mixture of Add 2 (Hostanox PAR 24 P a or Irgafos 168) and Add 10 (Hostanox 010 P a or Irganox 1010) | Phenol, 2,4,6-tris(1,1-dimethylethyl)-(Alkofen B)b CAS No. 732-26-3 Benzenepropanoic acid, 3,5-bis(1,1-dimethylethyl)-4-hydroxy-, methyl ester (Metilox ou Irganox 1300: structure very close to that of Irganox 1076)b CAS No. 6386-38-5 Octabenzonea |
| Add 10 | Hostanox 010 P (Irganox 1010) CAS No. 6683-19-8 = Tetrakis [methylene(3,5-di-tert-butyl-4-Hydroxyhydrocin-namate)] methane a |
Benzenepropanoic acid, 3,5-bis(1,1-dimethylethyl)-4-hydroxy-, octadecyl ester (Irganox 1076)a CAS No. 2082-79-3 Benzenepropanoic acid, 3,5-bis(1,1-dimethylethyl)-4-hydroxy-, methyl esterb Phenol, 2,4,6-tris(1,1-dimethylethyl)-(ou Alkofen B)b CAS No. 732-26-3 |
| Add 12 | Hostanox 016 FF (or Irganox 1076) CAS No. 2082-79-3 (powder) = Octadecyl-3,5-di-tert-butyl-4-hydroxyhydrocinnamate a |
Benzenepropanoic acid, 3,5-bis(1,1-dimethylethyl)-4-hydroxy-, methyl esterb CAS No. 6386-38-5 |
| Add 14 | Hostavin Aro 8P CAS No. 1843-05-6 = 2-Hydroxy-4-noctyoxybenzophenone (Octabenzone)a |
Octabenzonea CAS No. 1843-05-6 |
| Add 16c | Hostavin N20 P CAS No. 64338-16-5 = 2,2,4,4-Tetramethyl-7-oxa-3,20-diaza-dispiro-[5.1.11.2]-heneicosan-21-ob |
Octabenzonea 2,2,4,4-Tetramethyl-3,20-diaza-7-oxadispiro[5.1.11.2]heneicosan-21-oneb CAS No. 64338-16-5 |
| Add 17c | Hostastat FE 2P CAS No. 31566-31-1 = Glycerol monostearate b |
Hexadecanoic acid, methyl ester (Methylpalmitate)b CAS No. 112-39-0Methylstearate CAS No. 112-61-8 Octabenzone a |
Note that substances deriving from the commercial molecule, are not all permitted for food contact (not all in the positive list) (see notes a and b of Table 8).
Finally, some GC/MS results have revealed new molecules, quite different from those provided by the supplier. These include for example the Octabenzone (or Cyassorb UV 531, Hostavin Aro 8, etc.) and the Metilox (or Irganox 1300) present in additives Add 7, 10, 16, 17. They are either additives added to the commercial molecule to stabilize the polymer (case of Octabenzone) or intermediates for the synthesis of additives (such as the Metilox used in the synthesis of phenolic antioxidants (Pitteloud and Dubs, 1994)). Note that Octabenzone must have a risk assessment and authorization prior to use (Regulation (EU) No. 10/2011 of the Commission of 14 January 2011).
The Metilox is of low toxicity in acute toxicity tests, with an oral LD50 value higher than 5000 mg/kg (SIDS Initial Assessment Report for 13th SIAM, 2001).
3.3.3.2 The packaging extracts
The GC/MS results of extracts analysis are presented in Table 9. The compounds detected are:
| Manufacture | Sample | Polymer type | GC/MS identification |
|---|---|---|---|
| A | Ech 1 | Pebd | Methylpalmitate isomer |
| Ech 2 | PP | Methylpalmitate Irgafos 168 oxidized form |
|
| B | Ech 3 | Pebd | Benzaldehyde dimethyl acetal Methylpalmitate Erucamide |
| C | Ech 4 | PS | Methylpalmitate Polysiloxanne |
| Ech 5 | PS | Methylpalmitate Phtalic acid, 2-methoxyethyl tetradecyl ester Methadone N-oxide |
|
| D | Ech 6 | PS | Benzene 1,1′-(1,2-cyclobutanediyl) bis-cis- Methyl palmitate Octadecanoic acid, methyl ester |
| E | Ech 7 | PS | Benzene 1,1′-(1,2-cyclobutanediyl) bis-trans Methylpalmitate Octadecanoic acid, methyl ester |
| Ech 8 | PS | Benzene1,1′-(1,2-cyclobutanediyl) bis-cis Octadecanoic acid, methyl ester |
|
| F | Ech 9 | Pehd | Irgafos 168 |
| G | Ech 10 | PP | Benzaldehyde dimethyl acetal Benzaldehyde 3,4-dimethyl-Methylpalmitate Octadecanoic acid, methyl ester Methylpalmitate isomer Bumetrizole |
| Ech 11 | PP recycled | Benzaldehyde dimethyl acetal Benzaldehyde 3,4-dimethyl-Methylpalmitate Octadecanoic acid, methyl ester Irgafos 168 oxidized Bumetrizole |
|
| H | Ech 12 | PP | Benzoic acid, 4-ethoxy-, ethyl ester Propanoic acid, 2-methyl-(1, 1-dimethylethyl)-2-methyl-1,3-propanediyl ester Dodecanoic acid, 1-methylethyl ester (isopropyl laurate) Benzyl Benzoate: ascabin, ascabiol |
| Ech 13 | PP | Unox 4206: Chissonox 206 Propanoic acid, 2-methyl-(1,1-dimethylethyl)-2-methyl-1,3-propanediyl ester Isopropyl laurate Benzyl Benzoate: ascabin, ascabiol |
|
| I | Ech 14 | PEhd | DL-2,3-butanediol (6982-25-8) Structure close to: propanoic acid, 2-methyl-, butyl ester (97-87-0) Benzoic acid, 4-ethoxy-, ethyl ester (23676-09-7) I-propyl dodecanoate Structure close to: glutamide (1121-89-7) Benzyl Benzoate: ascabin, ascabiol Irganox 1076 1,3–Dioxolane, 2-methyl-2-(1-methylethyl)-(4405-16-7) Structure close to: Valeric anhydride (2082-59-9) DIOP: Diisooctyl phtalate (27554-26-3) |
| J | Ech 15 | PS | Benzyl Benzoate: ascabin, ascabiol Irganox 1076 Methadone N-oxide |
| K | Ech 16 | PS | Propanoic acid, butyl ester: UN 1914 Benzyl Benzoate: ascabin, ascabiol Irganox 1076 Methadone N-oxide |
| L | Ech 17 | PP | Benzoic acid, 4-ethoxy-, ethyl ester (23676-09-7) Carbamodithioic acid, diethyl, ethyl ester I-propyl dodecanoate Benzyl Benzoate: ascabin, ascabiol 3,6,9,12,15-oxabicyclo(15,3)heneicosa-1(21),17,19-triene-2,16-dione Irganox 1076 Caradate 30: diphenylmethane diisocyanate MEHP: 1,2 benzenedicarboxylic acid, mono 2-(ethylhexyl ester) |
| M | Ech 18 | PP | Propanoic acid,2-methyl-, butyl ester: butyl isobutyrate Benzoic acid, 4-ethoxy-, ethyl ester (23676-09-7) Benzyl Benzoate: ascabin, ascabiol 1,4 benzenedicarboxylic acid, bis (2-hydroxyethyl)ester: bis (2-hydroxyethyl) terephtalate Irganox 1076 Caradate 30: diphenylmethane diisocyanate Citroflex A: Tributyl acetylcitrate DIOP: Diisooctyl phtalate (27554-26-3) |
| N | Ech 19 | PSE | Benzyl Benzoate: ascabin, ascabiol Irganox 1076 DIBP: Phtalic acid, diisobutyl ester DIOP: Diisooctyl phtalate (27554-26-3) Methadone N-oxide |
| Ech 20 | PSE | Benzoic acid, methyl ester: niobe oil (93-58-3) Benzyl benzoate: ascabiol (120-51-4) Irganox 1076 DBP: Dibutyl phtalate (84-74-2) Decanedioic acid, dibutyl ester: Polycizer DBS (109-43-3) Methadone N-oxide |
3.3.3.2.1 lubricants
Most samples analyzed contain polymeric lubricants. The most commonly used is the Methylpalmitate. Even if it does not appear in the positive list, it is found mainly in polystyrene packagings. The lubricants improve the mechanical strength of PS. They can change the rheology of the polymer melt. They are applied either in bulk or in surface to reduce friction with the thermoforming equipment and increase the flexibility of PS (http://www.chemicalland21.com). Some PP or LDPE samples contain this additive or its derivative (Benzaldehyde 3,4-dimethyl-Methylpalmitate). There is also Methylstearate (Octadecanoic acid, methyl ester) in polypropylene and polystyrene packaging. But this additive is not in the positive list and according to Lewis (2008), it has tumorigenic effects.
Erucamide is a lubricant more rarely used (present only in the LDPE sample Ech 3). This is a fatty acid amide slip agent (Zweifel et al., 2009). It is integrated by the manufacturer of polymers in an extruder pellet or by the processor through masterbatches (Zweifel et al., 2009). The European Regulation No. 10/2011 authorizes the use of Erucamide for the manufacture of packaging for food contact (Regulation (EU) No. 10/2011 of the Commission of 14 January 2011). No migration limit has been prescribed for this additive. However, it has been shown that it tends to migrate into the food (Bart, 2006). Recently, several volatile compounds have been found in water from PET bottles exposed to sunlight. Bach et al. (2012) have shown that they come from the photooxidation of Erucamide present in bottle closures. Unfortunately, the closing equipment has not been analyzed and this hypothesis could not be confirmed.
The Niobe oil identified in a PSE sample (Ech 20) is also a lubricant permitted by the European Regulation No. 10/2011. Typical lubricants are fatty alcohols (C12–C22) or fatty acids (C14–C18) (Piringer and Baner, 2008). The isopropyl laurate (C15H30O2) identified in the Ech 12 of PP is probably a lubricant but is not in the positive list. The molecules of butyl isobutyrate and propyl laurate (I-propyl dodecanoate) are probably deriving from lubricant agents (CxHyOz).
3.3.3.2.2 The plasticizers
Much of the packaging analyzed are composed of benzyl benzoate (Ascabiol). It is a plasticizer (Simonds et al., 1944) but it is not reported as an additive or auxiliary polymer production in the positive list (Regulation (EU) No. 10/2011 of the Commission of 14 January 2011). It seems to have a low degree of toxicity (McEvoy, 1993) and it does not appear to cause mutagenic effects (Dollery, 1991). There is no much documentation about it on pregnancy and reproduction. However, it is not recommended for pregnant women (Ascabiol package insert; Ascabiol data sheet; McEvoy, 1993; Dollery, 1991; Koren, 1990).
Then we have found mainly phtalates in PSE packaging and sometimes in HDPE (Ech 14) and PP (Ech 17 and 18). We have identified DIBP, DIOP, DBP and MEHP.
DIBP is not reported as an additive or auxiliary polymer production in the positive list (Regulation (EU) No. 10/2011 of the Commission of 14 January 2011). However, it is found quite frequently in plastic packaging (Shen, 2005). The phtalic acid ester is a plasticizer (Di Bella et al., 2010; Whelan, 1994) that tends to migrate to fatty foods such as olive oil (Di Bella et al., 2010; Nanni et al., 2011). Toxicological studies in mice have also shown that DIBP had effects on the reproductive system (testis) (Shinshi and Kogo, 1980). For economic reasons, the DIOP is a plasticizer (with eight carbon atoms) which is most widely traded (Whelan, 1994; Brydson, 1999). It is compatible with the polystyrene (Whelan, 1994). It is approved by the FDA as constituting food packaging materials that come in contact with aqueous foods, but not with fatty foods (Gooch, 2011).
DBP can be used as an additive or auxiliary production of polymers with a 0.3 mg/kg LMS. Strict rules are defined for this additive (Regulation (EU) No. 10/2011 of the Commission of 14 January 2011). It should be used as a plasticizer in materials and articles contacting with food grease. And it may be a processing aid in polyolefin in concentrations up to 0.05% in the final product (Regulation (EU) No. 10/2011 of the Commission of 14 January 2011). This is an endocrine disruptor (Zimmer, 2008) and according to Zimmer (2008) and to the Council Regulation (EEC) No. 793/93 (1993), it is classified among the three most toxic phtalates to reproduction (with DEHP and BBP).
MEHP is not in the positive list and studies have shown that it decreases testicular testosterone in mice (Papadopoulos, 2007). For Harris and Sumpter (2001), MEHP is the most toxic metabolite of DEHP. Articles are increasingly interested in food packaging plasticizers based on phtalate: one speaks repeatedly of “endocrine disruptors”, (Muncke, 2009). In addition to phtalates, we have noticed the presence of plasticizers to lower toxicity in the samples Ech 20 and Ech 18: dibutyl sebacate (DBS) and acetyl tributyl citrate (ATBC or Citroflex A).
The DBS is an aliphatic acid ester used as a substitute to phtalates. Because of their high cost compared to phtalate, sebacate derivatives are used for targeted applications (Marcilla et al., 2004.). The DBS can be used as an additive or auxiliary production of polymers but strict rules are defined for this additive (Regulation (EU) No. 10/2011 of the Commission of 14 January 2011). It is found as a plasticizer for polystyrene (Senichev and Tereshatov, 2004). This is one of the most effective plasticizers of the sebacate type. It is non toxic, and is suitable for use in food packaging (Gooch, 2011).
ATBC is a citrate plasticizer that is mainly found in PVC plastic (Fankhauser-Noti and Grob, 2006; Marcilla et al., 2008). Fankhauser-Noti and Grob (2006) showed the ability of this additive to migrate into fatty foods used as an additive or auxiliary polymer production but with very specific restrictions (Regulation (EU) No. 10/2011 of the Commission of 14 January 2011). It has low toxicity by ingestion according to the Handbook of green chemicals (Muncke, 2009).
And, the expanded polystyrene contains more plasticizers than other polystyrenes plastics. They are added to increase flexibility, workability or distensibility of expanded plastic (Craver and Carraher, 2000).
3.3.3.2.3 antioxidants
Antioxidants found in our samples are often Irganox 1076 (or derivatives: Propanoic acid, 2-methyl-(1,1-dimethylethyl)-2-methyl-1,3-propanediyl ester) and Irgafos 168 (or its oxidized forms). Phenolic antioxidant Irganox 1076 (Hostanox 016) is present in both polystyrene (PS, PSE) and polyolefin (PP and HDPE). Several studies use it as a model to describe the specific migration of the additive from plastic into food (Galotto et al., 2011a, 2011b; Sanches Silva et al., 2006). Its ability to migrate is well known. It can certainly be used as an additive or auxiliary polymer production (LMS = 6 mg/kg) (Regulation (EU) No. 10/2011 of the Commission of 14 January 2011) but with labels R 53 and S 61 (Pigments & Additives Division – Clariant, 2006). The ICP analyses also have shown that the Hostanox 016 contains a high lead content compared to other tested stabilizers.
Then, the phosphite antioxidant Irgafos 168 (Hostanox PAR 24) appears mainly in PP and HDPE samples, not in polystyrene (PS and PSE). This additive is authorized for food contact (LMS undefined in the positive list) [F]. It does not have a high content of heavy metals, except copper (see ICP results). Other phosphite antioxidants are considered toxic: arylsubstituted phosphites (Lefaus, 1968), triphenyl phosphite (highly toxic), etc. Lau and Wong (2000) examined that trisubstituted derivatives are much more toxic than the mono and the disubstituted one.
It is important to note that all PP packaging analyzed contain antioxidants (including Irganox 1076 and Irgafos 168). The presence of antioxidant is necessary in PP packaging. Indeed, the polypropylene is highly branched. Its viscosity decreases rapidly in processing machine because of many chain scissions. Knowing that the polyolefin oxidation depends on their branching degree, the polypropylene (highly branched) is very sensitive to oxidation (Carette, 1993).
The phosphite antioxidant reduces the polypropylene coloration during thermal aging. But these antioxidants are very sensitive to hydrolysis; their effectiveness may decrease during storage (Carette, 1993). Polypropylene also contains Bumetrizole (2(3′-tert-butyl-2′-hydroxy-5′-methylphenyl)-2H-5-chlorobenzotriazole). It is generally used to slow the oxidation process of the polymer exposed to UV light. It preferentially degrades itself and helps in this way to stabilize the polymer (Lau and Wong, 2000).
Benzotriazole derivatives do not have high toxicity. However, they are still tested for possible genetic effects. Their use as antioxidants in the packaging materials is allowed but not for fatty food contact (Lau and Wong, 2000). However, the GC/MS results indicate its presence in a container used for an olive oil packaging.
Finally, we have noted the absence of antioxidants in LDPE packaging. The degree of branching of LDPE is quite low, split strings are few and branching reactions are numerous. The LDPE viscosity in processing machine decreases less rapidly than that of polypropylene (Carette, 1993). This phenomenon can be attributed to the presence of vinylidene groups in LDPE: LDPE is not very sensitive to oxidation (related to the branching degree). However, it can be stabilized by phenolic antioxidants of low molecular weight at low concentrations (less than 0.05%), associated with phosphites (Carette, 1993).
3.3.3.2.4 The other stabilizers
Benzoic acid, 4-ethoxy-, ethyl ester (Cas No. 23676–09-7) is identified in HDPE and PP packaging. It can be used as an additive or auxiliary polymer production (LMS = 3.6 mg/kg) (Regulation (EU) No. 10/2011 of the Commission of 14 January 2011). It is typically found in water bottles made of PET with a significant ability to migrate (Lilya, 2001).
Polypropylenes also contain Chissonox 206 (Vinyl cyclohexene diepoxide) and Caradate 30 (Methylenebis (phenyl isocyanate), MDI). The Chissonox 206 is generally used as a monomer in the production of epoxy resins for coatings and adhesives, as a chemical intermediate and as a reactive diluent in some epoxy resins deriving from bisphenol A and epichlorohydrin (Pohanish, 2012; Report on Carcinogens, 2011). It seems to have a carcinogenic effect in humans (Report on Carcinogens, 2011; ICSC, 1998 validated; IARC, 1987; IARC, 1994). However, no specific regulations are reported to reduce exposure to this substance (Report on Carcinogens, 2011). The Caradate 30 is generally used in the production of polyurethane foams and in plastics, polyurethane coatings, elastomers and thermoplastic resins (Pohanish, 2012). LMS is not reported for this product but according to Sittig’s Handbook of Toxic and Hazardous Chemicals and Carcinogens (Pohanish, 2012), its ingestion can cause abdominal cramps and vomiting.
3.3.3.2.5 Other compounds: NIAS (NIAS = substances not intentionally added)
Other molecules have been identified in the samples but few studies link them to plastic packaging. For example, polystyrene contains the Methadone N-oxide and Propanoic acid, butyl ester (UN 1914). Low density polyethylene and polypropylene contain the Benzaldehyde dimethyl acetal. High-density polyethylene contains 1,3-dioxolane, 2-methyl-2-(1-methylethyl-, DL-2,3-butanediol, glutamide (Cas No. 1121-89-7) and Valeric anhydride. These compounds can be considered as “not intentionally added” (NIAS) ones. They are produced by initial reactants or additives authorized (Bach et al., 2012) and they can be considered as contaminants in food packaging (Lau and Wong, 2000).
3.3.4 Quantitative analysis of Irgafos 168 (Add 2) in packaging
The calibration curve gives the area ratio of Irgafos 168 and the internal standard versus the ratio of concentrations for these two substances.
The calibration curve equation is: y = 1.9724x − 0.3008
The concentration of Irgafos 168 (ConcIrgafos168) is given by the following equation:
ConcIrgafos168 = 2.5x (ppm), avec ConcSI = 2.5 ppm
The chromatograms of the analyzed samples are shown in Fig. 6.
Table 10 presents the concentration (ConcIrg 168) and the percentage of Irgafos 168 (%Irg 168) in the packaging analyzed.
| Plastic sample | Final product | Area ratio (IRG/SI) y | Concentration ratio (IRG/SI) x | ConcIrg 168a (ppm ou mg/kg) | m (g)b | % Irg 168c |
|---|---|---|---|---|---|---|
| Ech 2 | Chamia packaging | 3.0741688 | 1.7110975 | 4.2777 | 20 | 0.043 |
| Ech 9 | Yoghurt pots | 2.6435581 | 1.4927794 | 3.7319 | 8.75 | 0.037 |
| Ech 10 | Oil packaging | 1.5885023 | 0.9578697 | 2.3947 | 257 | 0.024 |
| Ech 11 | Chips from the production of oil packaging | 1.4532048 | 0.8892743 | 2.2232 | 10 | 0.022 |
Knowing for example that the mass of a small pot of yogurt is 8.75 g, we have 32 mg of Irgafos 168 in this pot (8.75.10−3 × 3.7519 mg), corresponding to 0.037%.
It has been found that the antioxidant content is variable in the polyolefin but always under 0.05%. The highest is that of polypropylene Ech 2 (chamia box). Next is the High Density Polyethylene Ech 9 (yoghurt) and polypropylene Ech 10 (oil container). This percentage decreases even more when the polymer is reground for other uses (such as the polypropylene Ech 11 for detergent container). Samples Ech 10 and Ech 11 have an Irgafos 168 lower rate than other packages but they are constituted of other stabilizers such as Bumetrizole (see Table 9). Plastic packaging producers use the parameters of quantity and variety of additives to stabilize their product.
4 Conclusion
Based on the analyses performed on several additives, we have observed that these additives sometimes contain compounds harmful to human health and environment. First, the additives are not always pure products. They are often mixed with resins and waxes (rosin), oils (paraffin), etc., which do not appear in the positive list for food contact. These substances are often found when the additives are fat or liquid form (see FTIR results).
Moreover, the GC/MS results have shown additives structures quite different from the commercial structure: it corresponds to degradation products, etc. For example, this has been observed in the antioxidants analysis. They are not very stable and they are highly sensitive to hydrolysis and heat.
We have also detected new molecules (Octabenzone, Metilox), entirely absent from the additive data sheets. They are either other additives to stabilize the polymer (synergistic effect), or intermediates for the adjuvants synthesis. Some of these molecules are not very toxic (ex: Metilox) but most of them are not mentioned in the positive list.
Then, some adjuvants contain significant levels of heavy metals. This is the case for lead in the phenolic antioxidant Hostanox O16FF, cobalt in Hostanox O10 P, O10FF and O3P, or nickel and copper in the phosphite antioxidant Hostanox 24FF. These levels explain their labels (R 53 or S 61). Lead tends to be increasingly replaced by cadmium-zinc. This is the case of some antioxidants “blend” as Hostanox Blend M 101P. Antistatic agents are often not approved for food contact. Moreover, the GC/MS results show that they are absent from food packaging. Their Nickel, Manganese, Chromium and iron concentrations are sometimes quite high (case of Hostastat FA 38).
Moreover, even if the additive concentration in packaging remains quite low (see HPLC results performed on Irgafos 168), we have counted a large variety of them (see GC/MS results of plastic extracts). The most common are lubricant agents, particularly Methylpalmitate and Methylstearate. However they are not in the positive list and the second one is “tumorigenic”. Other lubricants authorized for food contact, are rarely used (ex: Erucamide and Niobe oil). Then, one plasticizer usually identified is the benzyl benzoate (Ascabiol). Even if its toxicity level is low, some studies do not recommend it for pregnant women. There are also many phtalates: DIBP, DIOP, DBP and MEHP. Most of them are not in the positive list (DIBP, MEHP) or are not allowed to make contact with fatty foods. However we find them in meat packaging (ex: DIOP in Ech 14 and Ech 19, DBP in Ech 20). Some of them are even highly toxic. This is the case for DBP, which is still allowed with a LMS = 0.3 mg/kg. Phtalates are in general harmful to the reproductive system: they are characterized as “endocrine disruptors”. Some plasticizers, less toxic, are substitutes for phtalates (ex: DBS, ATBC). But they are used for specific applications due to their high cost.
Then, antioxidants found in our samples are often phenolic (Irganox 1076) or phosphite (Irgafos 168). Many studies describe their migration into food. They are sometimes highly charged in Pb (case of Irganox 1076). But other antioxidants are considered more toxic (phosphites arylsubstituted, Triphenylphosphites, etc.). There are also benzotriazole derivatives such as Bumetrizole. They do not have high toxicity but they do not allow for contact with fatty foods. However, we have identified bumetrizole in packaging of olive oil.
Packagings contain other stabilizers such as Chissonox 206, Caradate 30 and Benzoic acid, 4-ethoxy-, ethyl ester. The first one presents a carcinogenic effect on humans and the second can cause abdominal cramps and vomiting. No migration limit or other restrictions are reported for these two substances. The Benzoic acid, 4-ethoxy-, ethyl ester are allowed with LMS 3.6 mg/kg. Other compounds are found in our plastic packaging: The Methadone N-oxide, Propanoic acid, butyl ester (UN 1914), benzaldehyde dimethyl acetal, 1,3-Dioxolane, 2-methyl-2-(1-methylethyl)-, DL-2,3-butanediol, glutamide and Valeric anhydride. These are probably not intentionally added substances (NIAS). Even if they come from initial reactants or additives allowed, they can be considered as contaminants in food. It is necessary to combine chemical and toxicological data and determine the origin (impurities, byproducts, etc.) and the content of these compounds.
In conclusion, we have noted that packaging manufacturers do not generally exceed the additive authorized levels. However they allow the use of compounds harmful to consumer health (phtalates, etc.). It is therefore imperative to educate people on the contents of the packages they use daily. We must develop communication about the purpose and applications of these packaging: containers not authorized for fatty food contact should not contain meat!
Finally, it is necessary to encourage the use of substitutes for harmful additives. In the case of plasticizers for example, phtalates may be replaced by sebacate or citrate molecules.
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