Food contact

Fluoropolymer resins are covered in the United States by Food, Drug and Cosmetic Act 21 CFR and 177.1380 and 177.1550 and in the European Union by the EC Directive 90/128 [5]. Several fluoroplastics (e.g., PTFE, PEA, FEP) have been approved by the FDA for contact with food. Additives, such as stabilizers, antioxidants, and pigments, must be approved to meet the food additive regulations if they have no prior clearance [5]. 

Ideally, an antistatic agent should be permanent. It should not lose its efifeet, as blooming types do, by migrating too quickly to the surface where it could be removed by washing or abrasion. Its action should be independent of the relative humidity, and it should allow the produet to be light coloured or even transparent, which rules out carbon black. The antistatie agent should not rule out food contact applications. The industry has been addressing these problems, and considerable developments have taken place. 

The technique used to achieve permanence with other additives such as antioxidants and plasticisers has often been to increase the molecular weight of the additives. In the ease of antistatic agents, however, high molecular weight versions of conventional antistats require high loadings, and can significantly increase costs. 

Over 50% of the consumption of traditional blooming antistatic agents consists of ethoxylated amines and glyceryl monostearate (GMS), and much of the rest consists of alkyl sulfonates, fatty alkanolamides and amide ethoxylates. Films containing amide antistats usually pass the American Mil-B-81705C (commonly known as Mil spec) test for electrostatic dissipation when the film is a few days old, but not after three or four weeks. This has been attributed to the formation of crystallites of the antistatic agent. 

Traditional antistats bloom to the surface and may interact with food in food packaging. Food contact approval can therefore be an important requirement. Ethoxylated amines produced from standard coco fatty acids are mixtures that can contain relatively low molecular weight acids, some with as few as 8 or 10 carbon atoms. This low molecular weight component has traditionally prevented their acceptance for food applications because most regulations have stipulated between 12 and 18 carbon atoms. EU regulations (Directive 2002/72/EC, 6 August 2002) have now extended the minimum downwards to 8 carbon atoms (See Chapter 7). 

Arkema (formerly AtoFina) and its subsidiary CECA have marketed Noroplast 3000, a hquid at ambient temperature, to provide the same antistatic performance as a coco ethoxylated amine, whilst fulfilling European and US criteria authorising indirect food contact. Uniqema has secured FDA approval for its Atmer 163 antistatic agent, a synthetic ethoxylated amine, at levels not exceeding 0.1% by weight, in moulded or extruded PP homopolymers and 

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Indirect Food Additives Subpart B Substances for Use as Basic Components of Single and Repeat Use Food Contact Surfaces," Code of Federal KegulationSs Tide 21, Part 177, U.S. Government Printing Office, Washington, D.C., 1994. 

Aqueous solutions of propylene glycol display excellent antifree2e properties and are therefore valuable as low temperature heat-transfer fluids. For apphcations involving indirect food contact, heat-transfer fluids formulated with the USP grade product are preferred, since there could be inadvertent contact with a food product. These fluids are commonly used in the brewing and dairy industries as well as in refrigerated display cases in retail grocery stores. 

During processing at elevated temperatures, normal precautions are needed to prevent accidental bums. Sudyn ionomers have U.S. Food and Dmg Administration clearance for food contact. Information about ionomers can be found in the articles Ethylene Acrylic acid and derivatives and Methacrylic acid and derivatives. 

Upon satisfactory deterrnination of nontoxicity of a lubricant, the USDA issues one of two ratings HI for use where there is incidental or possible food contact as by splashing or dripping from machinery above an edible product, or H2 for no food contact as in sealed gear boxes or machinery below a product line (82—84). These classes include a number of petroleum and synthetic oils and greases. 

LLDPE by itself does not present any health-related hazard on account of its chemical inertness and low toxicity. Consequently, film, containers, and container Hds made from LLDPE are used on a large scale in food and dmg packaging. Some LLDPE grades produced with unsupported metallocene catalysts have an especially high purity due to high catalyst productivity and a low contamination level of resins with catalyst residue. FDA approved the use of film manufactured from these resins for food contact and for various medical appHcations (80). However, if LLDPE articles contain fillers, processing aids, or colorants, thek health factors must then be judged separately. 

PVC—nitrile mbber permanent plasticization of PVC, improved processibihty wire and cable insulation, food contact service 141,317,318... 

There is a health benefit associated with hindering hydrogen bonding. Alkylphenols as a class are generally regarded as corrosive health hazards, but this corrosivity is eliminated when the hydroxyl group is flanked by bulky substituents in the ortho positions. In fact, hindered phenols as a class of compounds are utilized as antioxidants in plastics with FDA approval for indirect food contact. 

Rosin has a low order of toxicity foUowing ingestion or skin contact. Rosin and its numerous derivatives have a number of permitted food packaging and other direct and indirect food contact uses throughout the world. Sanctioned uses appHcable in the United States are outlined in U.S. Food and Dmg Administration (U.S. FDA) Regulations (2). Material Safety Data Sheets (MSDSs) for specific rosins and thein derivatives should be consulted before thein use. 

Diamine curatives were the first cross-linking agents for fluorocarbon mbbers. They are corrosive to mild steel molds and have been replaced in many appHcations by the bisphenol or other more recent cure systems. Nevertheless, some diamines are stiU used for food-contact appHcations of fluorocarbon mbbers and in zinc-free cures of halobutyl mbbers for pharmaceutical stoppers. Methylene dianiline and triethylene tetramine are cross-linking agents for ethylene—acryflc elastomers. 

Calcium—zinc stabilizers are used in both plasticized PVC and rigid PVC for food contact where it is desired to minimize taste and odor characteristics. AppHcations include meat wrap, water botdes, and medical uses. 

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. 

Cellulose esters are considered nontoxic and may be used in food-contact appHcations. However, since cellulose esters normally are not used alone, formulators of coatings and films for use in food packaging should ensure that all ingredients in their formulations are cleared by the United States Food and Dmg Administration for such use. 

Cellulose gum is the accepted common name for purified CMC. It may be used in milk products, dressings, jellies, symps, beverages, and other select products. It is permitted in food contact and packaging appHcations. 

Specifications and Standards Test Methods. Hydroxyethylcellulose is included in the Hst of materials that are in compHance with requirements of the U.S. EDA for use in adhesives and in resinous and polymeric coatings employed on the food-contact surfaces of metal, paper, or paperboard articles, and other substrates intended for use in food packaging as specified in CER 21. HEC made dispersible by cross-linking with glyoxal is cleared only as an adhesive and as a component of paper and paperboard in contact with food. It has not been cleared as a direct food additive. 

Specifications and Standards Test Methods. Ethylcellulose is cleared foi many apphcations in food and food contact under the Eedeial Eood, Dmg, and Cosmetic Act, as amended. Examples include binder in dry vitamin preparations for animal feed, coatings and inks for paper and paperboard products used in food packaging, and closures with sealing gaskets for food containers (44). Methods of analyses ate given in ASTM D914-72 (19), NationalFonmila XIV, and Food Chemicals Codex II. 

Citric acid esters are used as plasticizers ia plastics such as poly(viayl chloride), poly(vinhdene chloride), poly(viQyl acetate), poly(viQyl butyral), polypropylene, chlorinated rubber, ethylceUulose, and cellulose nitrate. Most citrate esters are nontoxic and are acceptable by the FDA for use in food-contact packaging and for flavor in certain foods. As a plasticizer, citrate esters provide good heat and light stabiUty and excellent flexibiUty at low temperatures. Triethyl citrate, tri- -butyl citrate, isopropyl citrate, and stearyl citrate are considered GRAS for use as food ingredients (224—228). 

In handling EP(D)M, normal industrial hygienic procedures should be followed. It is advisable to minimi2e skin contact. The use of EP(D)M is permitted for food contact under the conditions given in the respective EDA-paragraphs 177.1520 for Olefin polymers, and 177.2600 for mbber articles intended for repeated use. 

Other uses for which special compounds have been developed include materials intended for food contact, wire insulation, and pharmaceutical appHcations. 

In 1998 it was also announced that PEEK had obtained FDA approval for food contact applications. This raises the possibility of the material being used for such purposes as food containers, bearings and seals for processing equipment and as a coating for metals in non-stick cookware. 

Polyterpenes enjoy a number of FDA approvals. They are not only suitable for adhesives with indirect food contact, but also for use in both chewing gum and in films that will have direct food contact. Their higher price compared to petroleum-derived equivalents has resulted in a significant decline in usage over the past 10 years, except where FDA approvals dictate their usage. 

The methods of analysis of polymer additives and chemicals, such as hydrocarbons, alcohols, etc., are not only restricted to the field of polymer chemistry but can also be applied for the analysis of such materials in the field of food chemistry. In addition, the analysis of polyaromatic hydrocarbons in edible oils has been of extreme importance. Polymeric packaging materials that are intended for food-contact use may contain certain additives that can migrate into the food products which are actually packaged in such products. The amounts of the additives that are permitted to migrate into food samples are controlled by government agencies in order to show... 

Fig. 10-7 Example of a typical toxicology study for a plastic for industrial us, non-food contact.

Another concern, is the potential reactivity of 10 as a transfer agent under polymerization conditions (see 3.3.1.1.4).103 Tetramethylsuccinonitrile (9) appears to be essentially inert under polymerization conditions. However, the compound is reported to be toxic and may be a problem in polymers used in food contact applications.1" 30 Methacrylonitrile (MAN) formed by disproportionation readily copolymerizes.7"34 The copolymerized MAN may affect the thermal stability of polymers. A suggestion103 that copolymerized MAN may be a "weak link" in PS initiated with AIBN has been disputed.14... 

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