Food contact plastics, additives

Apart from routine quality control actions, additive analysis is often called upon in relation to testing additive effectiveness as well as in connection with food packaging and medical plastics, where the identities and levels of potentially toxic substances must be accurately known and controlled. Food contact plastics are regulated by maximum concentrations allowable in the plastic, which applies to residual monomers and processing aids as well as additives [64-66]. Analytical measurements provide not only a method of quality control but also a means of establishing the loss of stabilisers as a function of material processing and product ageing. 

For standard or proprietary polymer additive blends there is the need for analytical certification of the components. Blend technology has been developed for two- to six-component polymer additive blend systems, with certified analytical results [81]. Finally, there exist physical collections of reference additive samples, both public [82] and proprietary. The Dutch Food Inspection Service reference collection comprises 100 of the most important additives used in food contact plastics [83-85]. Reference compounds of a broad range of additives used in commercial plastics and rubber formulations are generally also available from the major additive manufacturers. These additive samples can be used as reference or calibration standards for chromatographic or spectroscopic analysis. DSM Plastics Reference Collection of Additives comprises over 1400 samples. 

Table 5.18 Main functional classes from the EEC inventory of additives intended for use in Food Contact Plastics Materials (Commission of the European Communities, 1991) [222]...

This presentation discusses current EU chemical legislation and examines the shortcomings of some of the regulations in place with respect to dangerous chemicals. The Commission White Paper is discussed, and in particular, the REACH system which involves the registration, evaluation and authorisation of chemicals used in food-contact applications. The impact of the REACH system on food-contact plastic manufacturers is examined, with respect to suppliers of monomers and additives, plastic manufacturers, converters and packagers. 

At the time of writing, DEHA has not yet been included in the EU positive list of additives used to make food contact plastics. With an established TDI of 0.3 mg/kg bw/day and using the normal conservative assumptions of 1 kg food consumed daily and a 60 kg bw, this TDI would give a specific migration limit of 18 mg DEHA per kg food or food simulant. It must be recognised that non-compliance with a migration limit of 18 mg/kg based on this convention does not necessarily mean that the TDI could be exceeded. It seems unlikely that DEHA will be listed until the issue of food consumption factors is resolved. 

BEGLEY T, CASTLE L, FEIGENBAUM A, FRANZ R, HINRICHS K, LICKLY T, MERCEA P, MILANA M, O BRIEN A, REBRE s, RIJK R and PiRiNGER o (2005), Evaluation of migration models that might be used in support of regulations for food contact plastics . Food Additives and Contaminants, 22(1), 73-90. 

In a second step, the harmonisation of additives used in plastic food contact materials was started. However, this step is not yet finished Therefore, additives listed both in the Community legislation and in national legislation can be used in food contact plastics (for national lists see section 3.7). It is foreseen that harmonisation on additives will be finalised by 2007. Until 31 December 2006 all parties interested in additives authorised at national level have to supply EFSA with a valid application for evaluation of this additive. Only additives for which a valid application has been supplied may continue to be used according to national audorisation until evaluation is finalised by EFSA and a decision on authorisation is taken by the European Commission. The Community list on additives contains those additives that are used solely in plastics and those used both in plastics and coatings. However, it does not contain additives used only in plastic coatings, adhesives and epoxy resins. 

TBC is used as a plasticizer that does not support fungal growth in cellulosic and vinyl resins (especially PVC), polyactic acid resins (as a biodegradable component), and furniture coatings. Also used as a solvent for nitrocellulose and lacquers intended for food contact applications. Additional applications include a defoaming agent in proteinaceous solutions. 

A provisional list of additives for the production of food-contact plastics has been published, anticipating an EC Directive on these additives, and their characterization by several techniques, including NMR, is described.273 The problem of the interactions of food with packaging materials has also been addressed by a study of the migration of some food additives into packaging materials, using NMR in tandem with UV-Visible spectrophotometry.274... 

Currently, for additives, there is an incomplete list existing because the harmonised evaluation of all additives is not yet finalised. It is to be noted that for manufacturing food contact plastics, only positive list substances are allowed as additives [6]. 

Sustainable products need to be safe to use. Safety of additives that can leach out of food-contact plastics has drawn considerable public attention. Endocrine disrupter effects (see Chapter 7) and toxicity often attributed to plastic products (Chapter 8) are often due to additives such as phthalate plasticizers and brominated flame retardants. What is not sustainable is to keep using additives that are evidently hazardous (and those with unknown ecological impacts) simply because they have superior performance and are economically the best choice. Alternative additives that not only match or exceed the performance of conventional ones but do not pose a threat to the biosphere including its human occupants, need to be developed as replacements for the ones in question. 

Typically, transition metals, such as manganese, iron, cobalt, and nickel (but not heavy metals), are used to catalyze peroxide decomposition (Andrady et al, 1996). Their additive masterbatches are used at very low levels, and the metals are therefore present at very low concentrations of about 0.01 and 0.5% weight in the plastic product (Amaud et al., 1994). Some of the plastics with these additives have been approved for use in food contact plastics in the United States and in Canada. 

Y. Ogawa, U. Kawamra, C. Wakui, et al.. Estrogenic activities of chemicals related to food contact plastics and rubbers tested by yeast two-hybrid assay, Food Addit. Contam. 

The Commission of the European Communities provides in Synoptic Document N, 7 [4] a provisional list of additives used for the production of food contact plastics. This Synoptic Document anticipates a Directive on additives for food contact plastics. One hundred of the most important additives were selected from this provisional list after extensive consultation with researchers in the field and with representatives from European industry (Food Contact Additives Panel (FCA) sector group of the European Chemical Industry Council (CEFIC). 

In 1994 the European Commission published a Synoptic Document No.7 [6] which provides a provisional list of additives suitable for the production of food contact plastics. 

This synoptic document [6] published in Belgium anticipates an EU Directive on additives used in food contact plastics. In 1998, van Lierop and co-workers [7] in support of what was at the time a future Directive, selected 100 of the most important polymer additives to establish a reference collection. 

Currently the EU Directive EEC2002/72 [2] establishes positive lists of monomers and additives, which can be used in the manufacture of food contact plastics. But the Commission is now proposing regulations relating to labelling, traceability and certification. 

Negishi T, Kawasaki K, Suzaki S et al (2004) Behavioral alterations in response to fear-provoking stimuh and tranylcypromine induced by perinatal ejqmsure to bisphenol A and nonylphenol in male rats. Environ Health Perspect 112(11) 1159-1164 Ogawa Y, Kawamura Y, Wakui C et al (2006) Estrogenic activities of ehemicals related to food contact plastics and rubbers tested by the yeast two-hybrid assay. Food Addit Contam 23(4) 422-430... 

These additives are available in black and light gray colors which are easily pigmented for high appearance applications. Furthermore the additives have received a favorable review by the FDA for inclusion in food contact plastics. 

Food and pharmaceutical grades of calcium carbonate are covered by the Food Chemicals Codex (7) and the United States Pharmacopeia (8) and subject to U.S. Food and Dmg Administration Good Manufacturing Practices (9). Both purity requirements and test methods are available (7,8). Calcium carbonate is listed in the U.S. Code of Federal Regulation as a food additive, and is authorized for use in both paper and plastic food contact appHcations. 

---