J. Pack. Sci. Tech. Vol.8 No.6 (1999)

Endocrine Disruptor Screening and Testing :The U. S. Approach
G. E. Timm, A. F. Maciorowski
Office of Prevention, Pesticides, and Toxic Substances
U. S. Environmental Protection Agency
Washington, DC 20460

Over the past five years, endocrine disrupting chemicals have emerged as a major environmental
science and policy issue. Documented effects to fish and wildlife populations, coupled withevidence from human poisonings, epidemiology, and experimental toxicology have led to an
emerging hypothesis that chemicals may be affecting reproduction and development. In
response to these concerns, the U. S. Congress passed the Food Quality Protection Act (FQPA)
and the Safe Drinking Water Act (SDWA) Amendments of 1996. The FQPA requires EPA toscreen pesticides for estrogenic effects on human health and permits EPA to screen chemicals
found in drinking water sources for other hormonal effects. Faced with implementing a new
regulatory program, EPA responded by sponsoring focused research to better understand thebasic science of endocrine disruption, and by establishing the Endocrine Disruptor Screening
and Testing Advisory Committee (EDSTAC) to advise the Agency on the design of an
endocrine disruptor screening program. EPA is currently implementing a screening program
based on EDSTAC's recommendations.

1. INTRODUCTION
Scientific evidence has accumulated that humans, domestic animals, and fish and wildlife
species have displayed adverse impacts from exposure to chemicals that interact with theendocrine system [1, 2]. To date, such problems have been best documented in humans, anddomestic and wildlife species that have been exposed to high concentrations of organochlorinecompounds (e.g., DDT and its metabolite DDE, PCBs, and dioxins), and to a few naturally
occurring plant estrogens [3]. Numerous reports indicate a variety of compounds canmodulate the endocrine system and affect reproduction and development in invertebrates, fish
and wildlife. However, few examples are currently available that establish the extent towhich these insults have resulted in adverse population responses[4]. It is also unclear,whether adverse effects in the human population at-large can be attributed to environmental
concentrations of contaminants operating through endocrine modulation. Conflicting reports
regarding declines in the quality and quantity of sperm production in humans have been
published [1]. Although reported increases in cancers of endocrine sensitive tissues (e.g.,- 2 7 3 -Endocrine Disruptor Screening and Testing : The U. S. Approachbreast, prostate, testicular) are clear, there is little direct evidence linking disease trends with
exposure to environmental pollutants. An endocrine-related basis for such effects is
plausible, but considerable scientific uncertainty exists. Nevertheless, there is little doubt that
small disturbances in endocrine function, particularly during certain highly sensitive stages ofthe life cycle (e.g., development, pregnancy, lactation), can lead to profound irreversible
adverse effects [3, 4].
Taken collectively, the body of scientific research on human epidemiology, laboratory
animals, fish and wildlife provides a plausible scientific hypothesis that environmental
contaminants can disrupt the endocrine system leading to adverse health consequences. A
critical issue is whether ambient environmental concentrations are sufficiently high to exert
adverse effects on the general population. Epidemiology, mammalian toxicology, andecological toxicology investigations are all necessary to resolve the fundamental scientificquestions and uncertainties surrounding the endocrine disruptor issue.
The U. S. has implemented a two-part approach to endocrine disrupters. The first is a
research program to increase understanding of the basic scientific issues concerning endocrine
disruption. The second, the subject of this paper, is a regulatory screening and testing
program to identify and characterize the effects of endocrine disrupting chemicals.

2. ENDOCRINE DISRUPTOR SCREENING PROGRAM
Faced with increasing concern over endocrine disrupting chemicals and adverse human healthoutcomes, the U. S. Congress passed two laws that contained provisions for screening
chemicals for their potential to disrupt the endocrine system. The Food Quality Protection
Act of 1996 (P. L 104-170), 21 U.S.C. § 346a(p) ) requires EPA to :"develop a screening program using, appropriate validated test systems and otherscientifically relevant information, to determine whether certain substances may have aneffect in humans that is similar to an effect produced by a naturally occurring estrogen,or such other endocrine effect as the Administrator may designate."
When carrying out the screening program, EPA (A) "shall provide for the testing of all
pesticide chemicals" and (B) "may provide for the testing of any other substance that may
have an effect that is cumulative to an effect of a pesticide chemical if the Administrator
determines that a substantial population may be exposed to such a substance." 21 U. S. C. §346a(p)(3). In addition, Congress amended the Safe Drinking Water Act (42 U. S. C. § 300j17) authorizing the EPA to screen contaminants in drinking water to which substantial
numbers of people would be exposed.
The congressional mandate to develop a screening program in a controversial and rapidly-274-

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emerging area of science led EPA to establish The Endocrine Disruptor Screening andTesting Advisory Committee (EDSTAC) in October 1996. The EDSTAC was charged withadvising the Agency on the development of a practical, scientifically defensible endocrine
disruptor screening strategy. The EDSTAC consisted of 39 members representing thepesticide and chemical manufacturers, state and Federal government, and environmental andpublic health advocacy organizations.
At its first meeting, EDSTAC expanded the scope of its deliberations to include potential
effects on the androgen and thyroid systems in addition to estrogen. The Committee cited
numerous examples of anti-androgen and anti-thyroid agents and the impact that thesesystems have on reproduction, growth and development as reasons for their inclusion.
Ecological effects were also deemed important in that ecological effects have provided thestrongest evidence of endocrine disruption to date. Finally, EDSTAC also included chemicals
other than pesticides and drinking water contaminants as candidates for screening and testing.
The universe of candidate chemicals under consideration included approximately 900 pesticide
active ingredients ; 2,500 pesticide formulation inert ingredients ; 75,500 industrial chemicals ;and 8,000 cosmetics, food additives and nutritional supplements [5].
The overall frame work that EDSTAC recommended consists of four major steps : (1) initialsorting of chemicals, (2) establishment of screening priorities, (3) Tier 1 screening, and (4)Tier 2 testing. The initial sorting step was intended to separate the chemicals into four
discrete categories. Category 1 consists of polymers with a numerical average molecularweight (NAMW) greater than 1,000 daltons and certain exempted chemicals that are unlikely
to display endocrine activity (e.g. , certain biologically inactive ingredients or highly reactive
substances such as strong mineral acids and bases that will react at the portal of entry).
Polymers with the specified NAMW will be set aside pending a review of their monomers.
Such polymers were thought to pose little risk because, they are generally too large to passthrough biological membranes and interact with the endocrine system. Polymers that are
identified as posing a potential risk because of their monomers or additives will probably beevaluated through leaching and stability studies rather than whole animal toxicity studies.
Category 2 consists of chemicals with insufficient data to determine their potential for
endocrine activity. Category 3 includes those chemicals that have sufficient data to bypass
screening, but need testing. Finally, Category 4 consists of substances with adequate data
which will be referred to the appropriate agency for hazard assessment.

2.1 Priority Setting
The largest category of chemicals, and that of greatest interest to EPA concerning screening,-275-

Endocrine Disruptor Screening and Testing : The U. S. Approach

are those chemicals with insufficient information and data (Category 2). EDSTAC consideredseveral different approaches for setting priorities among these chemicals. One consisted ofranking chemicals with known exposure and effects as the highest priority for screening andtesting. EDSTAC was concerned, however, that such an approach would focus attention on
the most studied chemicals, resulting in a low priority for chemicals that were little studied.
The Committee also recognized that priority setting is not generally an objective, data-driven
process. Comparable, equitable, and uniform data are simply not available for the majority
of commodity chemicals. As an example, ranking a chemical that has extensive monitoringdata in wildlife against one known to have human exposure, but entirely lacking effects data
in mammals, is not a simple task. The Committee wanted a system in which like informationand data could be compared in priority setting, but one that was also subject to clearly statedvalue judgments to ensure public confidence. The approach recommended by EDSTAC wastermed a "compartment-based" priority setting strategy.
In the compartment-based strategy, a number of compartments (or sets) of chemicals aredefined and the individual chemicals within each set are prioritized. One might think ofmathematics and sets of numbers as an analogy. In mathematics one could define sets of real
numbers, integers, irrational numbers, even numbers, etc. Numbers within each set could
then be ordered in some fashion. Some numbers obviously belong to more than one set, andthe same will hold true for chemicals. One could define a set of high production volume
chemicals, chemicals measured in biota, chemicals in consumer products, chemicals detectedin the workplace, etc., and then prioritize the chemicals within each group. Given the large
number of chemicals that must be prioritized for screening, implementation will undoubtedly
occur in phases or batches. Once the sets of chemicals are defined and prioritized, a batch ofchemicals will be selected for the initial phase of the screening program. The contribution ofeach set of chemicals to this batch is the key subjective judgment that must be made in thepriority setting process. The size of the first batch and spacing of subsequent batches ofchemicals depends largely on the available laboratory capacity of the system, the ability ofindustry to pay for testing, and the resources of the EPA to review submitted data.
Although EDSTAC did not reach agreement on the definition or weighting of specificcompartments, EDSTAC listed the following categories and specific kinds of information thatshould be considered in developing the compartment-based approach.
A. Exposure-Related Information
1. Biological sampling data
2. Environmental, occupational, consumer product, and food-related data (sampling and/or
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3. Environmental releases
4. Production volume
5. Fate and transport data and models
B. Effects-Related Information
1. Toxicological laboratory studies and databases
2. Epidemiologic and field studies and databases
3. Predictive biological activity or effects models (e.g. Structure Activity Relationships[SAR] and Quantitative Structure Activity Relationships [QSAR])
4. Results of high throughput pre-screening (HTPS)
C. Integrated Effects and Exposure Information
D. Specially Targeted Priorities
1. Mixtures
2. Naturally Occurring Non-Steroidal Estrogens
3. No minations
Following the basic framework and guiding principles laid out in the EDSTAC report, EPA
developed an initial "strawman" proposal for a compartment-based system which waspresented at a public workshop [6]. The proposed approach assumes that a database will be
developed to contain the rank-ordered lists of chemicals within each compartment as well as
the weights and algorithms to select chemicals for entry into tier 1 screening.
EDSTAC also recognized other problems for priority setting. Few chemicals actually havedata that directly measures their endocrine disrupting potential. Most chemicals have scanteffects data. Often these data are limited to short-term mutagenicity tests and acute toxicity
in rodents. Even chemicals that have been examined with respect to reproduction anddevelopmental effects were likely tested using conventional protocols that have not been
specifically designed to detect endocrine effects. EDSTAC believed that the most expedientmeans for obtaining useful endocrine effects data was to employ high throughput screening
technology (HTPS) to high production volume chemicals and pesticides. The first two in vitro
assays recommended by EDSTAC may, in fact, be conducted in a high throughput mode.
These assays are specific to receptor binding modes of action. However, all 15,000 highproduction volume chemicals could theoretically be assayed in approximately 3 to 6 months at
a relatively modest cost. This information could be used with production and exposure
information and data to assist priority setting for further screening. A positive result in thehigh throughput screen would raise the priority for testing a substance relative to its priority
based purely on production and exposure. Concomitantly, a negative in the high throughput
screen would neither raise nor lower the priority since a chemical could be endocrine active-277-

Endocrine Disruptor Screening and Testing : The U. S. Approachthrough mechanisms other than receptor binding.

2.2 Tier 1 Screening
EDSTAC built upon the work of other expert workgroups in reviewing candidate assays for ascreening system [7,8]. These expert groups reviewed a number of individual assays andconcluded that a battery of assays was necessary to evaluate endocrine disruption potential. They
further recommended that the battery include in vitro and in vivo assays. In vitro assays areadvantageous in that they are inexpensive and specific for a particular mode of action.
Conversely, they lack the metabolic and response complexity of intact animals. EDSTAC
recommended a battery of three in vitro assays and five in vivo assays for Tier 1 screening. The
in vitro assays include an estrogen receptor binding or reporter gene assay, an androgen receptor
binding or reporter gene assay, and a steroidogenesis assay using minced testes. EDSTAC
preferred functional assays over receptor binding assays because the former can be used todifferentiate agonist from antagonist activity, and they are also more sensitive than the latter [5].
The in vivo Tier 1 assays are :Rodent 3-day Uterotrophic Assay
Rodent 20-day Pubertal Female Rodent Assay with Thyroid
Rodent 5-7 day Hershberger Assay
Frog Metamorphosis Assay
Fish Reproductive Screen
Deliberate endpoint complementarity is incorporated into the screening battery, and the assays inthe battery are meant to work together as a whole. Thus, the ER reporter gene, uterotrophic
and pubertal female assays screen for estrogenicity and anti-estrogenicity. The AR reporter geneand Hershberger assays screen for androgenicity and anti-androgenicity. The frog assay andpubertal female assays screen for thyroid. The fish assay is mainly present because fish are theclass of vertebrates most distant from the mammals in terms of their metabolism and hormone
systems. Having diverse taxa in Tier 1 may provide some idea of when we can be confident ofconsistent results among organisms and when we must be concerned about variability. A weightof the evidence approach will be used to evaluate the results in Tier 1. In vivo results willoutweigh in vitro results. Chemicals testing negative in Tier 1 would be regarded as having low
potential for interaction with the estrogen, androgen or thyroid systems. Chemicals testing
positive would proceed for more in depth evaluation in Tier 2.
In addition to the assays listed above, EDSTAC recommended that EPA standardize andvalidate several alternative assays. These are the pubertal male, in utero assay and aromatase
assay. If the pubertal male assay is successful, it could replace the pubertal female,-278-

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Hershberger and steroidogenesis assays but the aromatase assay would have to be added sincemales are not a good model for studying aromatase. The in utero assay could potentiallyreplace all of the mammalian in vivo assays since it embraces all potential modes of action [5].

2.3 Tier 2 Testing
The Tier 2 tests are meant to identify adverse effects due to endocrine disruption and toestablish a relationship between dose and response. The criteria identified by EDSTAC for
Tier 2 tests was that the most sensitive life stage be tested (in utero or in ovo), that the tests
be multi-generational and that each major taxonomic group be represented. Thus EDSTAC
recommended five multi-generation tests : one each in mammals, birds, fish, amphibians andinvertebrates. In theory, Tier 2 can be tailored based on both exposure and effects
information. For instance, if it can be shown that only exposure to humans will occur, only
the 2-generation test in rodents will be required. Unfortunately, the limited number of species
represented in Tier 1 makes it unlikely that one will have sufficient information to tailor the
Tier 2 test menu on the basis of Tier 1 results alone.

3. EPA IMPLEMENTATIONEPA is currently implementing EDSTAC's recommendations. EPA published a notice in theFederal Register on December 28, 1998, to obtain comments on its proposed screening
program and implementation plans. The proposed screening program and the implementation
plan were peer reviewed by the EPA Science Advisory Board and FIFRA Scientific Advisory
Panel in March 1999.

3.1HTPSA pilot demonstration of HTPS was completed in March 1999 to determine the suitability of theassay system for commercial chemicals and pesticides. Both stable and transient transfectedreporter gene constructs were prepared based on T47D cells for the estrogen receptor (ER),MDA 453 cells for the androgen receptor (AR), and HeLa cells for the thyroid receptor (TR).
The goal of identifying weak agonists and antagonists for ER, AR and TR was never realized
due to low signal to noise ratio caused by less than optimal induction and well-to-well cross talk.
EPA decided to widen its search for an HTPS system. It will try to identify an off-the-shelftechnology for HTPS and could proceed with HTPS if this new effort is successful. If HTPS
is not shown to be a feasible approach, EPA may rely on the use of quantitative structure
activity relationships (QSARs) to meet the objective of a quick way to provide an indicator of
potential hormonal activity of unknown chemicals for priority setting purposes.

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3.2 Standardization and Validation
The Food Quality Protection Act also states that the screens and tests be validated to ensure thatthey give reliable and repeatable results. A task force has been established in the U.S. to coordinate
the standardization and validation effort among government, industry and public interest groups.
International standardization and validation efforts are being conducted separately from U.S.
domestic efforts. Through its Test Guidelines Program, OECD has established the Endocrine
Disruptor Testing and Assessment Task Force. Laws, regulatory processes, and regulatory
procedures differ in the United States, Japan and Europe. Thus, while EPA actively
participates as a member of OECD, the OECD Test Guidelines Program, and the OECD
Task Force, separate domestic and international activities are necessary. Althoughinternational activities are distinct from the U.S. task force activities, there is overlapping
membership to ensure appropriate liaison and communication, eliminate unnecessary
duplication of effort, and facilitate international harmonization, where appropriate.
The general validation framework we envision for endocrine disruptor screens and tests follows thegeneral process and stages developed by the U.S. Interagency Coordinating Committee for the
Validation of Alternative Methods (ICCVAM) and will proceed in six major stages : 1) Research andassay development 2) demonstration of relevance and standardization 3) interlaboratory validation 4)
scientific peer review ; 5) An independent scientific peer review ; and 6) Agency regulatory approval,
wherein we consider the peer review comments and recommendations and make a decision on theregulatory acceptability (or need for additional work) of the method in question [9].
EPA will initially place a higher priority on standardizing and validating the mammalian
assays used to assess health hazard and risk because The Food Quality Protection Act and the
Safe Drinking Water Act are explicitly directed toward protecting food and drinking water tosafeguard human health. The ecotoxicological screens or tests remain important because
EPA cannot evaluate ecological hazard and risk on the basis of mammalian tests alone. EPA
will develop and evaluate the screens and tests using a phased approach with resources
allocated especially for endocrine disruptor screening and testing validation. Resources will
be conserved by carefully selecting the chemicals to be used in the standardization andvalidation program. It is estimated that two years will be required to standardize and validate
the screens and perhaps up to five years will be required for some of the newer tests.

4. CONCLUSIONS
Many policy issues in the United States and abroad will be decided before the resolution of
all scientific questions. Nevertheless, we see that the results of screening and testing and theanswers to many of the questions posed by the research agenda will combine to form our-280-

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conclusions regarding the level of risk that endocrine disruptors pose to humans and wildlife.
Ultimately in the United States, risk management actions will be taken under current U.S.
laws - laws that are mainly risk based and, therefore, which require the integration andinterpretation of effects and exposure data.

References[1] European Workshop on the Impact of Endocrine Disruptors on Human Health andWildlife ; EUR 17549 ; European Commission : Brussels, Belgium, 1996.
[2] Expert Workshop on Endocrine Modulators and Wildlife : Assessment and Testing,
Tatters field, L., Matthiessen P, Campbell P, Grandy N., Lange R., Eds.; SETACEurope ; Brussels, Belgium, 1997.
[3] Kavlock R., Daston G., DeRosa C, Fenner-Crisp P., Gray E., Kaattari S., Lucier G.,
Luster M., Mac M., Mackzka C, Miller R., Moore J., Rolland R., Scott G., SheehanD., Sinks T., Tilson H., Environmental Health Perspectives. 1996, 104, 715-740[4] Special Report on Environmental Endocrine Disruption : An Effects Assessment andAnalysis. Environmental Protection Agency : Washington, DC, EPA/630/R-96/012, 1997.
[5] Endocrine Disruptor Screening and Testing Advisory Committee : Final Report ;Environmental Protection Agency : Washington, DC , 1998. Available at littp://www.
epa. gov/scipoly/oscpendo/history/[6] Strawman" Priority Setting Process for Endocrine Disruptor Screening and Testing,
Environmental Protection Agency, January 7, 1999. Available at http: //www. epa. gov/
scipoly/oscpendo/strawman. htm[7] Ankley G., Mihaich E., Stahl R., Tillit D., Colborn T., McMaster S.. Bantle J.,
Campbell P., Denslow N., Dickerson R., Folmar L., Fry M., Giesy J., Gray E., GuineyP., Hutchinson T., Kennedy S., Kramer V., LeBlanc G., Mayes M., Nimrod A., Patino
R., Peterson R., Purdy R., Ringer R., Thomas P., Touart L., Van Dei Kraak G.,
Zacharewski T. , Environmental Toxicology and Chemistry. 1998, 17, 68-87.
[8] Gray E., Kelce W., Weis T., Tyl R., Gaido K., Cook K., Klinefelter G., Desaulnier D.,
Wilson E., Zacharewski T., Waller C, Foster P., Laskey J., Giesey J., Laws S.,
Mclachlan J., Breslin W., cooper R., Di Giulio R., Johnson R., Purdy R., Mihaich E.,
Safe S. , Colborn T., et al Reproductive Toxicology. 1997, 11, 719-750.
[9] Validation and Regulatory Acceptance of Toxicological Test Methods, A Report of the ad
hoc Interagency Coordinating Committee on the Validation of Alternative Methods, NIH
Report Number 97-3981 , National Institute of Environmental Health Sciences, Research
Triangle Park, NC 27709. March 1997.

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Safety of Food Packaging Materials
Vanee Komolprasert, Ph.D.
Division of Food Processing and Packaging, US Food and Drug Admin istration,
National Center for Food Safety and Technology,
6502 S. Archer Road, Summit-Argo, Illinois 60501, USA
The International Packaging Seminar (IPS'99)
June 29, 1999

A b s t r a c t
This paper will focus on two studies that are directly related to the safety issues of food packaging materials.
The first study determined whether the secondary recycled polyethylene terephthalate (PET or PETE) was
suitable for direct food contact applications. The second study determined the effects of gamma and e-beamradiation on food packaging intended for use with prepackaged irradiated foods.
In the first study, the test protocol suggested by the FDA (FDA, 1992) for the chemical recycling processes
was used. The test protocol suggested the use of several surrogate chemicals with different physical andchemical properties to simulate the chemical contaminants that may be present in the recycled PET. Thesechemical contaminants could be introduced to the materials via misuse of the PET bottles for temporarystorage of chemicals such as gasoline, used motor oil, and household insecticides. The experiments involved
spiking virgin PET materials with these chemicals, and subjecting the contaminated PET to secondary(physical) recycling processes (aqueous-based washing, thermal drying and extrusion remelting). The
efficacy of the selected recycling process conditions on removal of the surrogates from the PET and thepotential migration of these chemical residues from the post-treatment PET into food simulating solvents
weredetermined.

The second study is ongoing. Food packaging materials of commercial interest have been selected as amodel, irradiated with gamma and electron beam radiation at various irradiation conditions and stored atvarious storage conditions. Volatile and nonvolatile compounds that are present in the test materials before
and after irradiation were analyzed and compared for the effect of irradiation on the test materials.
Analytical methods and some initial research results for evaluating the suitability and safety of the foodpackaging materials intended for prepackaged irradiated foods will be included.

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I. Recycled Polyethylene Terephthalate (PET) Food Containers
PET was the first polymer among other recyclable thermoplastics to be chosen by resin manufacturers to
examine its potential for recycling. Since the virgin PET polymer is synthesized by a condensation
polymerization reaction, a reverse reaction (hydrolysis, methanolysis or glycolysis) is employed to convert the
post-consumer PET material to initial reactants or monomers. The monomeric products are then purified
prior to resynthesis to polymeric PET material. These chemical processes based on depolymerization andrepolymerization have been tested using the test protocol suggested in the FDA's guidelines. The test
results indicated that they are adequate for removal of certain contaminants from recycled PET andconsequently, the regenerated PET material is suitable for food use. Several of these chemical processes
have been carefully reviewed by the FDA prior to a no-objection letter given to the manufacturers. By 1992,
at least three PET resin manufactures had received the no-objection letter.
Although the above chemical processes were successfully developed to recycle PET for food use, they areenergy intensive and costly. These processes make the regenerated PET less competitive with the virginmaterial. Therefore an alternative, such as a physical process that is simpler and less expensive, has been
considered. Several PET recyclers have attempted to develop a physical process that effectively generates
post-consumer recycled PET food container suitable for food use. Prior to 1991 there were no reported
physical PET recycling processes which would regenerate PET suitable for food use. Therefore, a study on
the effects of physical recycling processes on PET food containers was initiated in 1991 at NCFST.

Experimental
Surrogates: At least five surrogates with various physical and chemical properties were selected according
to recommendations in the FDA's guidelines (FDA, 1992). The selected surrogates were benzene (volatile,
non-polar), butyric acid (volatile, polar), malathion and diazinon (non-volatile, polar), dodecane (C12),
octadecane (C18), tetracosane (C24) and lindane (non-volatile, non-polar), and copper II ethyl hexanoate(heavy metal).
PET material: Specially blow-mold 2 L clear PET bottles made of virgin resins with round bottom and no cap
or base cup were used. They were pre-chipped prior to use. The PET chips were experimentally spiked
with each surrogate that was dissolved in an appropriate solvent at predetermined concentrations before
analysis and subsequent recycling processes.
Analytical Methods of Surrogates in PET: Volatile organic surrogates were analyzed by dynamic(purge/trap) and static headspace gas chromatography (HS/GC) with flame ionization detection, or polymer
total dissolution using trifluoroacetic acid (TFA) solvent followed by liquid-liquid partition (Komolprasert etal, 1994; Komolprasert and Lawson, 1994 and 1995). Nonvolatile organic surrogates were analyzed by total
polymer dissolution using hexafluoro-isopropanol or trifluoroacetic acid mixed with methylene chloride
followed by polymer precipitation and purification before quantification by GC with appropriate detectors(Komolprasert and Lawson, 1995 and Komolprasert et. al, 1995). Copper was analyzed using dry ashingwith modifications of the AOAC method (AOAC, 1990; Komolprasert Lawson, 1995).
Aqueous-based Washing: Commercial cleaning processes are proprietary and vary between recyclers;
however, most recyclers use aqueous-based washing with addition of chemicals such as detergent and caustic
soda. The design of a washing process that simulates an actual process was made using the limited
information published and personal communication with few recyclers. Although all commercial processes
are continuous, batch washing was selected for this study due to its simplicity and ease of controlling processparameters during washing. The chosen washing conditions were 1% Triton X-100 surfactant in water
maintained at 90°C for 20 min with 600 rpm mixer speed (Komolprasert and Lawson, 1994), followed bydeionized water rinse at 70-80°C for 15 min, filtered with a sieve shaker, and thermally dried using an IRlamp for 20 min or until dried PET flakes were obtained.

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Thermal Drying: Small-scale drying experiments were conducted using a lab muffle furnace. In theexperiments, the washed, spiked PET chips were placed in the furnace maintained at 160-170°C for 4 h tosimulate the desiccant dryer used commercially. The concentrations of surrogates remaining in the dried
flakes were subsequently determined using the analytical methods developed at the NCFST. The drying
conditions used in this study significantly reduced amount of most surrogates except copper from washedspiked PET chips (Komolprasert and Lawson, 1995).
Extrusion Remelting: The extrusion conditions for a Haake single screw extruder selected for generating
PET sheets was as follows: temperature gradient from feed zone to die zone 260-290°C, die gap of 2 mm, andvented screw speed of 20 rpm. An average throughput rate was 31-32 g/min. The results obtained
indicated that the remelting removed significant levels of some surrogates from washed and dried spiked
PET chips but the levels varied with the type and residual concentrations of the surrogates adsorbed on orabsorbed in polymer matrix. Regardless of the concentrations, the remelting did not have a significant
effect on lindane or copper (Komolprasert et. al., 1996).
Analytical Methods of Surrogates in Food Simulating solvents: The analytical methods for quantifying thesurrogates in 8% ethanol/water and in heptane were modifications of those used for quantitation of thesurrogates in the PET polymer (Komolprasert and Lawson, 1997; Komolprasert et al., 1997).
Migration: PET sheets were made from PET chips that had been spiked with various surrogates, washedand dried prior to extrusion remelting. The Haake single screw extruder was used to produce extruded PET
sheets with an average thickness in a range of 0.23-0.30 mm. The sheets had low crystallinities in a rangeof 6-15% as compared to 31% for 2-L PET bottle wall (Komolprasert et al., 1997). The residual
concentrations of the surrogates in the sheets was determined before they were used in subsequent
extraction experiments in 8% ethanol/water or heptane (FDA, 1993a). Concentrations of surrogates in theextracted PET strips and food simulants were determined, and compared to the 0.5 ppb threshold limit(Komolprasert et. al., 1997). The extraction data suggest that residual contaminants (surrogates) present in
the PET at levels ranging from 0.6 ppm benzene to 24 ppm copper salt migrated into food simulants at
concentrations lower than 10 ppb. This suggests that at these levels of residual contaminants the recycled
PET may be acceptable for food-contact use.

R e s u l t s
The results from small scale washing and drying experiments indicated that the surrogates were reduced
significantly but the efficacy depends on surrogate type, and initial concentration and washing conditions.
Washing at 90°C with 1% nonionic surfactant (Triton X-100) tends to remove most of non-polar, non-volatileorganics from the PET. Intensive drying at 160-170°C for 4 h removes most volatile compounds (benzene
and butyric acid) from the PET. The drying also removes C12 and C18 and non-volatiles (C24, malathion,diazinon and lindane) from the PET. The results from extrusion experiments indicate that there isadditional effect of extrusion remelting on removal of some surrogates being present in the recycled PET athigh concentrations except lindane and copper salt.
Although the concentrations of the residual contaminants in the washed, dried, and extruded PET chips
generated in this study were still high, the migration of these contaminants from the PET into the aqueous
ethanol and heptane food simulating solvents occurred at concentrations lower than 10 ppb. The 10 ppb
limit is calculated using assumptions from "Points to Consider" document (FDA, 1992) and it is the
maximum allowable concentration of the residual contaminant in the food simulant which will not exceed the
dietary concentration of 0.5 ppb (FDA, 1993b and 1995).
Based on the data obtained in this study, it can be concluded that it is possible to develop a physical recycling
process that is effective for regeneration of PET suitable for direct food-contact uses. As long as PET is stilla high demand in the market, more recyclers will attempt to develop other physical recycling processes thatare more economical than the existing ones. It is noteworthy that this study did not consider changes ofphysical and mechanical characteristics in recycled material which are also important in determining if therecycled PET provides the functionalities required by the product.

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II. Effects of Gamma and Electron-beam Irradiation on Food Packaging Materials
Irradiation is an effective technology for reduction and elimination of foodborne pathogens in foods, only ofparticular interest for those that are prepackaged prior to irradiation to avoid recontamination. Irradiation
for food just recently received an increased interest after red meat irradiation was approved by the FDA(FDA, 1997). In the irradiation process of prepackaged foods, the package itself could potentially undergochemical changes, which include cross-linking and degradation. The chemical compounds initially presentor the degradation products formed upon irradiation that could migrate into food at storage conditions are apotential safety concern. As a result, a premarket safety evaluation of the material is required by the FDA.
Most of the current permitted packaging materials were approved in the 1960's.
In general, the chemistry of gamma and electron beam (e-beam) irradiation is indistinguishable ininteractions with foods and microorganisms according to laboratory data. At a given dose permitted by the
FDA, both techniques are indistinguishable in efficacy relative to reduction of microbial load on food without
significant changes in food qualities. The chemical changes and migration characteristics of the radiolytic
products formed in newer packaging materials are lacking. The lack of modern materials approved for use
during irradiation has been cited as one of impediments to large-scale implementation offood irradiation forcontrol of foodborne pathogens in foods. Selection of packaging materials for use in food irradiation depends
on the resistance or stability of the material to chemical changes when irradiated at commercial doses.
These chemical changes are dependent on irradiation conditions, packaging and post-irradiation treatments.
At a given dose the e-beam processing deposits the ionizing energy to the material at a faster rate than
gamma radiation, often resulting in less oxidative degradation and improved performance of polymer
packaging. Although gamma radiation is currently the most common process, the use of e-beam technology
is emerging and therefore, the packaging materials for e-beam should be investigated prior to use.

Experimental

Test Materials: A soaker pad and four semi-rigid polyethylene terephthalate materials were used. The
soaker pad is usually used to absorb exudate of uncooked meat, poultry, pork, and seafood, and it iscomprised of cellulose and polyethylene (PE). The PET materials are: (1) Crystalline and oriented PET
homopolymer with 1.36 g/ml density, 25% crystallinity, and 0.30-0.33 mm in thickness. (2) Crystalline andoriented PET with 1.5 mole % isophthalic acid comonomer, 1.37 g/ml density, 30% crystallinity, and 0.28-0.30
mm in thickness. (3) Amorphous and nonoriented PET copolymer with 3 mole % cyclohexanedimethanoland 1.5% di-ethylene glycol, 1.33 g/ml density, 5% crystallinity, and 0.25-0.28 mm in thickness. (4)Amorphous and nonoriented PET copolymer with 31 mole % cyclohexanedimethanol, 1.33 g/ml density, lessthan 2% crystallinity and 0.25-0.28 mm in thickness.
The test material was pretreated to remove organic residues before placing in 20-ml headspace glass vials or
250 ml glass Jar. The HS vial was purged with ultra pure nitrogen before closing with aluminum lined
silicone septum and aluminum seal. The glass jar was also purged with nitrogen before closing with a
Teflon lined plastic screw cap.
Irradiation: The specimen vials were irradiated at ambient temperature using the Cesium 137 radiator orelectron-beam accelerator in a range of 5-50 kGy. The dose rate of the Cesium source has been establishedby using National Institute of Standards and Technology dosimeters and is approximately 0.1 kGy/min.
The radiation dose absorbed/received by the tested specimens was measured by a dosimeter made of alanine(Brucker Instruments, Inc., Billerica, MA) or FW-60 radiochromic film (Far West Technology, Inc., Goleta,
CA) according to the ASTM E1275 method. The unirradiated and irradiated specimen vials and jars werestored in a refrigerator before subsequent analyses.
Analytical methods: Volatile compounds present in the test materials were analyzed by using headspace
GC/FID and GC/MSD, and/or thermal desorption (Komolprasert et. al, 1999). Nonvolatile compounds wereextracted from the test specimen with a food simulating solvent (Adhikari et. al., 1997) or an appropriate
solvent and quantified by percent soluble solid (Komolprasert et. al., 1999). The nonvolatiles were extracted
from the soaker pad specimens using an aqueous 10% ethanol solution and 2-propanol solvent at 40°C up to- 2 8 6 -

J.Pack.Sci. Tech. Vol.8 No.6 (1999)

10 days. The nonvolatiles were extracted from the PET with boiling methylene chloride or the 10% ethanol
solution and n-heptane solvent at 40°C up to 10 days.

Initial Results
Soaker Pad: The results obtained from the HS/GC/MSD analysis at 90»C showed that the 7-kGy gamma
irradiation generated 2.3-3.14 ppm 1,3 di-tert-butyl benzene, 0.78-1.40 ppm nonanal, and 0.24-0.41 ppm
cyclopentanone. The 1,3 di-tert-butyl benzene is a degradation product of BHT antioxidant used in LDPE
layer for soaker pad fabrication. Irradiation significantly increased percent soluble solids extracted fromthe soaker pad specimens. After irradiation the soluble solid in the 10% aqueous ethanol solution was
0.43 % compared to 0.28% before irradiation. The percent solid extracted from soaker pad specimens using
2-propanol increased with storage time, ranging from 0.7 1 to 0.94 % in unirradiated and from 0.82 to 0.98 %in irradiated. Glucose and cellobiose that were generated from cellulose were present in the soluble solid
extracted from unirradiated and irradiated soaker pad specimens with 10% ethanol solution atconcentrations lower than 10 ppb based on soaker pad weight. The complete analysis of the soluble solid isunderway.
Semi-rigid Crystalline and Oriented PET: The qualitative results obtained from HS/GC/MSD analysis
performed at 106°C showed that the 25 kGy gamma irradiation generated 668-742 ppb formic acid, 868-922
ppb acetic acid, 17-32 ppb 1,3-dioxolane, and 47-71 ppb methyl-dioxolane based on PET weight of PET #1 and2. The results obtained from the thermal desorption performed at 200°C showed that irradiation generated
10-12 ppm acetaldehyde, 479-975 ppb 1,3-dioxolane, and 6.6-10.6 ppm methyl-dioxolane (Komolprasert et. al,1999). The concentrations of the two dioxolanes found from thermal desorption were much higher thanthose observed in the HS, although formic and acetic acids were not detected. It is possible that the formic
and acetic acids produced by irradiation underwent further reactions with ethylene glycol during thermal
desorption to form the dioxolanes.
The soluble solid extracted from various PET specimens before and after irradiation were in a range of 0.670.78%. PET cyclic trimer is the major component and is present at 0.41-0.50%, accounting for more than
50% of the percent total solid in PET (Komolprasert et. al, 1999). Statistically, irradiation did not increase
the soluble solid and cyclic trimer.
The overall results suggest that 25-kGY irradiation had a slight effect on increasing the volatile but not the
nonvolatile compounds detected in the PET specimens.
Semi-rigid Amorphous and Nonoriented PET: The PET materials have been irradiated with electron-beamaccelerator at ambient temperature at 5, 25 and 50 kGy. The volatiles are being analyzed using HS/GC/FID
and HS/GC/MSD. Nonvolatiles have been extracted using 10% ethanol and n-heptane food simulating
solvents. Irradiation did not increase the percent soluble solid. Regardless of irradiation, soluble solid
extracted from the PET using both food simulants is lower than 0.02% based on the PET weight.

Reference s
Adhikari, C, Komolprasert, V., and Thayer, D.W., 1997. Effects of gamma irradiation on soaker pads in thepresence of an aqueous food simulant. Poster presented at the annual IFT meeting, June 17,
Orlando,FL.
AOAC, 1990. Official Methods of Analysis of the Association of Analytical Chemists, Williams, S. (Editor),
15th Ed. Association of Official Analytical Chemists, Inc. Arlington, VA.
FDA, 1992. "Points to Consider for the Use of Recycled Plastics in Food Packaging: Chemistry
Considerations." Chemistry Review Branch, U.S. Food and Drug Administration, Indirect
Additives Branch, HFS-247, 200 C Street, S.W., Washington, DC 20204.
FDA, 1993a. "Recommendations for Chemistry for Indirect Food Additives Petition." Chemistry Review
Branch, U.S. Food and Drug Administration, Indirect Additives Branch, HFS-247, 200 C Street,
S.W., Washington, DC 20204.

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2 8 7 -

Safety of Food Packaging Materials

FDA, 1993b. "Food Additives: Threshold of Regulation for Substances Used in Food-Contact Articles,"Proposed Rules, Federal Register, Vol. 58, No. 195, pp. 52719-52726.
FDA, 1995a. "Food Additives: Threshold of Regulation for Substances Used in Food-Contact Articles," Final
Rule, Federal Register, Vol. 60, No. 136, pp. 36582-36594.
FDA, 1995b. "Recommendation for chemistry data for indirect food additive petitions." Chemistry Review
Branch, HFS-247, U.S. Food and Drug Administration, Washington, DC 20204.
FDA, 1997. "Irradiation in the Production, Processing and Handling of Food, Final Rule, Federal Register,
volume 62, No. 232, pp. 64107-64121.Komolprasert, V., Armstrong, D. and Hargraves, WA, 1994.
Determination of benzene in recycled polyethylene terephthalate (PET) by dynamic purge and trap
headspace gas chromatograph (HS/GC). Food Add. Contam. ll(5): 605-614.
Komolprasert, V., and Lawson, A, 1994. Effects of aqueous-based washing on removal of hydrocarbons fromrecycled polyethylene terephthalate (PET). Proceedings for the ANTEC?94 conferences of Plastics
Engineering, Society of Plastics Engineers (SPE), Vol. Ill: 2906-2909.
Komolprasert, V., Lawson, A.R., and Hargraves, W.A, 1995. Analytical method for quantifying butyric acid,malathion and diazinon in recycled polyethylene terephthalate). J. Agric. Food Chem. 43(8):1 9 6 3 - 1 9 6 5 .
Komolprasert, V. and Lawson, A., 1995. "Residual Contaminants in Recycled Poly (ethylene terephthalate)Effects of Washing and Drying," in Plastics, Rubber, and Paper Recycling: A Pragmatic Approach,ACS Symposium Series 609, C.P. Rader, S.D. Baldwin, D.D. Cornell, G.D. Sadler and R.F. Stokel(editors), pp. 435-444.
Komolprasert, V. and Lawson, A., 1997. Considerations for reuse of polyethylene terephthalate) bottles infood packaging: Migration study. J. Agric. Food Chem. 45(2): 444-448.
Komolprasert, V., Lawson, A. and Begley, T., 1997. Migration of residual contaminants from secondary
recycled poly(ethylene terephthalate) into food simulating solvents, aqueous ethanol and heptane.
J. Food Additives and Contaminants. 14(5):491-498.
Komolprasert, V., Lawson, A. and Gregor, A., 1996. Removal of contaminants from RPET by extrusion
remelting. J. Packaging Technology and Engineering, September, pp. 25-31.
Komolprasert, V., McNeal, T., Agrawal, A., Adhikari, C. and Thayer, D.W., 1999. Volatile and nonvolatilecompounds in semi- rigid polyethylene terephthalate after 25-kGy gamma irradiation. Poster
prepared for the annual IFT meeting, July 25, Chicago, IL

J. Pack.Sci. Tech. Vol.8 No.6 (1999)

Influence of the European and German Environment
Legislation on the Food Packaging Tecknology in Germany
Horst Weisser*

An overview is given about the European and German Environment Legislation on the Food Packaging

Technology in Germany. The following aspects are treated: Laws and regulations, DSD - Dual System Germany,methods for the recycling of used plastic bottles, life cycle assessment, reusable or refillable packaging,inspection of refillable bottles (empty bottle inspection machines, sniffers for plastic bottles). Finally a report isgiven on our own research about scuffing of glass bottles and the usability of pet bottles for beer.
Keywords: Packaging legislation, Green Dot, recycling of plastic and plastic bottles, life cycle assessment,
PET-recyclat, challenge-test, returnable or reusable packaging, sniffer, scuffing of glass bottles,
PET-bottles for beer, ageing of beer, beer flavour stability

1

Pa c kag ing C o nsu m pt ion and Recycling in Germany

The enthusiasm of German consumers for the separate collection of recyclable waste is unflagging. In 1998 theycollected a total of 5,622,525 t of used sales packaging manufactured from glass, paper, cardboard, plastics,
tinplate, aluminium and composites in the Green Dot collection containers. This even exceeded the high result of
5,618,445 t which was achieved in the previous year. Including impurities, 6,215,416 t (1997: 6,051,250 t) werecollected by way of the Dual System Germany１. This corresponds to a per capita collection of 75.8 kg (1997:
73.7 kg). The recycling and recovery requirements prescribed by the Packaging Ordinance were achieved for allmaterial fractions (Table 1).
With this result, the German public has once again proved by its actions that it considers packaging recycling to
be a good thing for the environment. This opinion which is also documented by life cycle analyses is reflected ina study published by the Gesellschaftfur Konsumforschung (GfK) in March 19992. According to this, almost
eight out often people questioned (77%) consider collection and recycling to be the best concept for the disposalof waste. Not even every fifth person ( 17%) is in favour of waste incineration, and only four percent are for landf i l l i n g .
Table 1

Recycling of used packaging in 1998 in Germany (DSD)

Institute for Brewery Installations and Food Packaging Technology, Technical Universityof Munich, D-85350 Freising-Weihenstephan, Germany- 2 8 9 -Influence of the European and German Environment Legislation on the Food Packaging Technology in Germany

2

Laws and Regulations

Several laws and regulations were ratified within the European Community (EC) and Germany to reduce theamount of packaging waste. The most important regulations for the packaging industry and the consumers are:- European Parliament and Council Directive 94/62/EC of 20 December 1994 on Packaging and Packaging
Waste- German Waste Avoidance, Recycling and Disposal Act (Kreislaufwirtschafts- und Abfallgesetz - KrW/AbfG) of 7 October 1996
- German Packaging Directive (Verpackungsverordnung - VerpackV) of 21 August 1998 (Regulations on the
avoidance of packaging disposal).
The cornerstones of the new legislation are: consistent application of the Polluter Pays Principle, creation of aprevention-oriented hierarchy of obligations (avoidance before thermal or material recycling), equal status ofthermal and material recycling, with the possibility of determining a priority in the case of specific waste forms
by statutory order and producers' responsibility for their products (to be reified in each case by statutory order).

2.

1

EU

Directive

94/62/EC

It can be assumed that everyone with a commercial interest in packaging is aware of the European Parliamentand Council Directive 94/62/EC on Packaging and Packaging Waste3. But probably few people realise that it
is not purely about environmental protection. Indeed, the purpose of the Directive was to complete the single
European market and this was the legal basis of its adoption late in 1994 by the then 12 EU member states
Directive 94/62/EC aims to harmonise the national packaging legislation with the twin objectives on the one
hand of preventing or reducing the environmental impact caused by packaging and packaging waste and on theother hand, ensuring the functioning of the Internal Market in a manner that the obstacles to trade and distortionand restrictions of competition can be avoided.
The Directive contains a list of must do and may do items for member states. The major risk of market disruption
results from the may do list. Examples include: member state mandatory quotas for reusable packaging;packaging Eco-Taxes; product specific targets for recovery and or recycling; bans on packaging which meet
European law essential requirements; some labelling and marking requirements and national products standards
for packaging.
Undoubtedly the most controversial and misunderstood of all these are reuse quotas. The Directive says
"member states may encourage reuse systems of packaging, which can be used in an environmentally soundmanner, in conformity with the Treaty". Quotas for reusable packaging contained in the 1991 German Packaging
Ordinance are presently the subject of an infringement action by the European Commission. The Commission
claims these quotas infringe Article 30 of the Treaty which prohibits quantitative restrictions on imports and allmeasures having equivalent effect. Brussels contends that the imposition of high reuse quotas for various typesof beverages sold in Germany puts foreign companies at a competitive disadvantage and is therefore a tradebarrier.

2.2

German Waste Avoidance, Recycling and Disposal Act

In 1 993, the German federal government decided to reformulate Waste Disposal Act (Abfall-Beseitigungsgesetz,
AbfG) on 1 0.06.72 into a Waste Avoidance, Recycling and Disposal Act (Kreislaufwirtschafts- und Abfallgesetz- KrW-/AbfG)4. The aim was to realise the economically viable recycling of materials within an environmental
and social market economy. The new, reformulated Act came into force on 07.10.96. With it, a new, preventive
concept of waste has been created. According to this concept, waste is no longer simply something that theowner wishes to be rid of, but also those substances, surpluses and residues, which are neither deliberately-290-

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produced nor used for any purpose. These include, for example, swarf or harmful industrial substances as well as
scrap cars or waste paper. The new waste concept, taken from European law, is now also applied at nationall e v e l .
The main goal of the new Act is to develop waste law and waste management towards a recycling economy. The
cornerstones of the new legislation are:- consistent application of the Polluter Pays Principle- the creation of a prevention-oriented hierarchy of obligations (avoidance before thermal or materialr e c y c l i n g )- the equal status of thermal and material recycling, with the possibility of determining a priority in the case of
specific waste forms by statutory order- producers' responsibility for their products (to be reified in each case by statutory order)
extending the opportunities for the privatisation of waste disposal.
Through integrated recycling of functional and auxiliary substances, such as solvents and oils for example, waste
is to be avoided as far as possible even at the production stage. On the other hand, the producers' responsibility
for their products which is now embodied in law should guarantee that products are structured in a manner thatwaste is avoided in their manufacture and use, and that an environmentally sound recycling and disposal isensured after their use.
In addition, unavoidable waste must be recycled in an environmentally acceptable way. In this, both thermal andmaterial recycling are equally permissible. In an individual case, the most environmentally sound manner ofrecycling has priority. The federal government is authorised to lay down the most environmentally sound mannerof recycling for individual waste forms through statutory orders. Thermal recycling is nonetheless only
permissible where: the waste has a calorific value of at least 1 1,000 kJ/ kg, the furnace operates at as a minimum
75% thermal efficiency, and the heat gained is used by the recycler or delivered to third parties.
Only those waste forms which cannot be recycled may be disposed of. With its strict requests, the Act
establishes a very high standard for the environmentally appropriate treatment and storage of the waste to be
d i s p o s e d o f .

2. 3

German Packaging Ordinance

The aim of the Ordinance5 is to encourage the avoidance and recycling of packaging waste. Among other things,
it stipulates that transport packaging, secondary packaging and sales packaging must be taken back and recycled,prescribes recycling quotas and expressly states that refillable systems must be protected and expanded. Insteadof a recycling quota, the original version of the Packaging Ordinance of 1991 contained collection and sortingq u o t a s .
The purpose of the Ordinance is to achieve a drastic reduction in the amount of packaging waste deposited onland fill sites and to organise a closed cycle for recyclable materials with a view to promoting the conservation ofr e s o u r c e s .
The intention to give the Packaging Ordinance of 1991 a comprehensive overhaul was voiced as far back as
1993. After several subject specialists had put forward their draft proposals, the first draft amendment drawn up
by the Federal Government failed to be accepted by the Bundesrat in April 1997. On the basis of the reading in
the Bundesrat, the rejected draft was then re-edited and additions were made to incorporate major demands fromthe federal states. Following an initial phase of intense political debate, a new draft was submitted by the Federal
Government and was this time passed by the Bundesrat in May 1998, thus enabling the Packaging OrdinanceAmendment to enter into force on 28 August 1998.
The amendments made to the Packaging Ordinance of 1991 predominantly lie in the following areas:

2

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Influence of the European and German Environment Legislation on the Food Packaging Tecknology in Germany

1) Those manufacturers and distributors, who do not want to join an established Dual System, must also in the
future submit documentary evidence to show that they have fulfilled the recycling quotas, thus ensuring that all
manufacturers and distributors subject to the Ordinance compete on an equal footing.
2) The main steps taken to promote competition within the waste disposal industry include to make the Dual
Systems responsible for organising waste disposal services - in the form of collection, sorting and recycling - anddemanding that all packaging collected are forwarded for recycling under competitive conditions and that waste
disposal companies make known the costs they incur for recycling individual packaging materials. In addition,
the basic conditions underlying competition between the different systems for different waste management
sectors are improved as the quotas to be met are determined in accordance with the volume of packaging
licensed by a system.
3) Packaging for products which contain hazardous substances has been incorporated into the area of packaging
covered by the Ordinance for the first time. Thus, these regulations have been brought into line with the scope ofvalidity of the EU Packaging Directive.
4) The recycling quotas stipulated have been revised on the basis of the principles of the new Product Recycling
and Waste Management Act (KrW-/AbfG). The ambitious figures laid down should be maintained. An
appropriate network of facilities should be set up for the purpose of achieving these quotas on a staggered basis
over a period of time and should reach completion during 1999.
5) The intended amendment continues to regard refillable beverage packaging as an ecologically advantageous
type of packaging and treats it appropriately.

Collection and Sorting Quotas
The first version of the Packaging Ordinance (valid from 1991 to 1998) prescribed deadlines and quotas for all
packaging materials for the collection and sorting of post-consumer sales packaging. To confirm that it wasmeeting the quotas for the collection, sorting and recycling of the collected sales packaging, the Dual System
submitted proof in the form of mass flow verifications to the Ministries for the Environment of the individualf e d e r a l s t a t e s o f G e r ma n y .
The quotas were continually increased until 1995, when the collection quota for all packaging materials was 80
percent, 80 to 90 percent of which had to be sorted. The collection and sorting quotas were abolished when the
Packaging Ordinance Amendment came into force and now only a recycling quota remains.

Refillable

systems

Refillable systems have a substance cycle already in use, predominantly for glass and sometimes PET packaging.
For example, consumers are demanded to pay a deposit on beverage bottles or yoghurt jars which is refunded
when the consumer brings the empty bottles and jars back to the retailer.
The Dual System is committed to maintain and expand refillables systems which have proven successful to date.
Under the Packaging Ordinance, the German beverage industry is obliged to meet a nation-wide refillables quota
of at least 72 percent. As can be seen in Table 2 this is not reached since 1997. In these days a heavy discussion
is going on what the Federal Government will require in the future.

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Table 2 The proportion of refillables in the beverage sector in Germany in %3

DualesSystemDeutschland–

DSD

In Germany a second (dual) waste management system for post-consumer sales packaging is supplementing theexisting public waste disposal service. Its legal base is the Packaging Ordinance. The Dual System is a privatelyorganised system for the collection and sorting of used packaging and it is operated by Duales System
Deutschland AG, or DSD, a non-profit organisation based in Cologne. It generates funding by charging licencefees for the use of the Green Dot symbol.

3.

1

Green

Dot

The green Dot is a registered trademark of DSD being used to identify sales packaging which can be recycled if
it is fed back into the Dual System's collection systems. Manufacturers, fillers and importers pay a licence fee
which entitles them to have their Green Dot packaging disposed of by the Dual System.
Austria. France, Belgium, Luxembourg, Spain, Portugal and Ireland have also set up (or are in the process ofsetting up) systems based on the model of the Dual System.
The DSD sets up collection systems close to consumers' homes and takes back used sales packaging inaccordance with the specifications of the Packaging Ordinance, thus exempting retailers and manufacturers fromtheir individual take-back obligations.
The DSD is monitored by the environment ministers in Germany's federal states to ensure that the collection andsorting quotas are met. Records of performance of the Dual System are produced in the form of mass flow
verifications.

Licence fees for the Green Dot
The Green Dot fee consists of a weight fee per material and an item fee. The item fee is calculated either
according to the volume or area of a piece of packaging (Figure 1).
In general, one item fee is charged for each piece of packaging (see Example Table 3). If individually wrapped
articles are packed together in a multipack, several item fees will be charged accordingly.

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Influence of the European and German Environment Legislation on the Food Packaging Tecknology in Germany"040 ,

Figure 1 Weight fee in DM/kg and Item fee in Pf/Item Packaging Material for the Green Dot

Table 3 Example: 250 g plastic yoghurt tub with aluminium lid

3.2

Plastic tub,6.62g×2.95DM/kg
Aluminium lid,0.51g×1.50DM/kg
Total weight fee

1.95Pf
0.08Pf
2.03PfVolume category V6(200-400ml)

0.70PfTotal licence fee

2.73PfMinus a reduction of 9.5% from 01.01.1991 on

2.47Pf

Green Dot - Society for System Technology

In 1997 DSD has set up its subsidiary company Green Dot - Society for System Technology (Der Grüne PunktGesellschaft für Systemtechnologie mbH), for pushing forward the process of developing efficient sorting
processmg and recycling techniques. The company's amassed expertise will help to reduce the Dual System's
waste disposal costs and to improve further the quality of the sorting process and the materials used for recycling
T a s k s a r e :- Promoting the development of sorting, processing and recycling technologies- International sale of German sorting, processing and recycling technologies.
The project with Japanese company Hitachi Ltd. is progressing very well. In 1997, the Hitachi group purchased
the rights to a processing system for mixed plastic waste and now intends processing mixed plastic packaging ina plant in Kita-Kyushu, Japan, before being used as a substitute for heavy oil in the reduction of iron or in blastf u r n a c e s 6 .

3.3

G e r m a n S o c i e t y f o r R e c y c li n g P l a s t i c M a t e r i a l - D G K

The German Society for Recycling Plastic Material (Deutsche Gesellschaft für Kunststoff-Recycling mbH DGK) is guarantor for the proper recycling of used plastic sales packaging marked with the Green Dot Before
the plastics collected through the Dual System can be recycled, they have to be sorted and, in some cases,
processed ready for recycling.
The Dual System sorting plants currently sort plastics into the following five fractions: Films such as plasticbags make up 26% of the total. Bottles, for example for shampoo or washing-up liquid, account for 9% Cups
and Tubs - most of them used for dairy products - and expanded polystyrene (EPS) together account for 2% All
these materials are high-quality plastics (PP, PE or PS) suitable for processing into regranulate. The largest shareof the sorted plastics is mixed plastics (around 63%). These are mostly small items and packages composed ofdifferent materials, or packaging components which cannot be economically separated. They are pressed into
bales and processed in special processing plants to produce a homogenous, pourable bulk material or
agglomerate. This is usually recycled as a feedstock.

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Methods of Plastic Recycling

Mechanical recycling: Mechanical recycling involves shredding, melting down and re-forming sorted
packaging, so the new plastic products are made of the same materials as the original products.
Feedstock recycling: With feedstock methods, the plastics are broken down into their constituent oils and gases.
Some sorting is required before this can take place, although it is just a matter of ridding the plastics of any
pieces of metal or foreign matter.

3. 3. 2

Recycling of the Mixed FractionMore than 60% of the sales packaging collected by the Dual System are heterogeneous and contaminated smallsized plastics. As further sorting into pure plastic fractions would make little economical sense, these plastics are
separated as the so-called mixed fraction. Pressed into bales they arrive at the preparation plant, where they areprepared for feed-stock recycling
Every feedstock preparation process starts with a shredding step: The plastics are processed into a homogeneousmaterial with a particle size of less than 50 mm which is easy to handle in subsequent preparation steps.
After the plastics have been coarsely shredded, impurities and household waste items which have not been
separated in the sorting plant have to be removed. Removing these impurities improves the processability of thematerial significantly and protects the machinery from excessive wear and damage. Magnetic separators are used
to isolate ferrous metals. Eddy-current devices handle the separation of non-ferrous metals such as aluminium.
Air separators and sieves are used to remove other impurities .
Compacting the material is an essential step in the preparation process. Three equipment alternatives areavailable: agglomerators, pelletisers and disc compactors. In a disc compactor, the shredded plastics arecompressed and plastified using high friction. The result of the compacting should be a homogeneous pourable
bulk material with a particle size of about 10 mm. Oversized granules are ground down or sieved out.
The output product of the preparation process is a mixed plastics agglomerate with a high density, a definedparticle size, a low chlorine content and little residual moisture. It can be used in all feed-stock recyclingp r o c e s s e s .
- In the hydrogenation process, the material is converted into synthetic crude oil (syncrude).
- The pyrolysis technique developed by BASF cracks the plastics into their basic chemical components.
And steel companies use the agglomerate as a reduction agent in their blast furnaces.

3. 3. 3

Examples of Feed-stock Recycling Processes

Methanol production: The SVZ (Sekundärrohstoff- Verwertungszentrum Schwarze Pumpe) recovers synthesis
gas from plastic waste. This primarily contains carbon monoxide and hydrogen and is a starting product forchemical syntheses. The SVZ uses it to produce methanol which for instance is required to produce plastics ora d h e s i v e s .
PARAK process: A feedstock recycling process for plastic waste (only PE and PP) with a mechanicalcomponent. With the aid of this method, the Paraffinwerk Webau GmbH recovers oils and paraffin from plastics.
Paraffin can be used universally, for instance as corrosion protection agent, wax, polish, the basis for creams etc.
Reduction process: Stahlwerke Bremen use a blast furnace process for the production of steel. The process is inprinciple a technique to produce pig iron for the steel industry. Plastics in the form of agglomerate are used here
in a I : I relation as a substitute for heavy oil, a reducing agent that is used to remove oxygen from the iron.

- 2 9 5 -Influence of the European and German Environment Legislation on the Food Packaging Teckiologv in Germany

Gasification process: SVZ (Sekundärrohsloff-Verwertungszentrum Schwarze Pumpe) has developed a highpressure gasification and Rheinbraun a high temperature Winkler process for gasification.
Hydrogenation: A feedstock recycling process implemented in the Kohleöl-Anlage Bottrop of VEBA AG. The
main product is a high-grade synthetic crude oil, syncrude, which can be used as feedstock tor the production ofplastics, gasoline, diesel fuel and heating oil. 800 kg of syncrude can be recovered from one tonne of mixed
plastics. These days it was decided that due to uneconomicalness the plant will be closed at the end of this year!
Cracking: BASF, Ludwigshafen has stopped the pilot plant on cracking of plastic feedstock.

4

Methods for the recycling of used plastic bottles

Different methods exist for the recycling of used plastic bottles. In the new developed process of OHL Company7
the recovered flakes from other recycling methods are extruded, recondensated and granulated in a speciallybuilt extruder to transform recovered flakes into an acetaldehyde-free product for 100% reuse in the plastic bottle
cycle. During the process, acetaldehyde, oligomers and all contaminants are eliminated, thus ensuring the pellets
are totally suitable for contact with beverages or food.
Schmalbach-Lubeca8 acquired the rights to the Supercycle® process when it took over the PET operations ofJohnson Controls. The food-grade Supercycle material is produced by a proprietary cleaning process whichworks so thoroughly that the recycled PET material and the bottles produced from it are completely free of any
contamination. This fact is confirmed by leading food-industry institutes in Europe as well as by the Food andDrug Administration in the USA, which has the strictest standards in the world. Schmalbach-Lubeca operates
two plants that recycle used PET containers by the Supercycle process: one in Novi, Michigan/USA, and since
the end of 1997 one in Beaune, France.

Figure 2 Example ofa Supercycle PET Bottle, Rosbacher Mineralbrunner9

4. 1

PET Recyclate for Direct Contact with Foodstuffs

For monitoring and sorting out contaminated plastic refillable bottles, a so-called sniffer is currently used as
standard on a bottle washing line. The application of this together with tests for the cleanliness, shape andsolidity (no leaks) of the bottles already guarantees a high degree of safety. There is however no information
about the chemical inertness of the refilled plastic bottles. This knowledge is indispensable for carrying out
quality controls in industry and for testing bottles already in the marketplace regarding their suitability for
consumables. The test also provides the basis for further material developments and economic
improvements.

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(1999)The Fraunhofer Institute for Process Engineering and Packaging (1VV) in Freising determined the present isstate of PET recyclates, namely the levels of the relevant migratory impurities, and also evaluated analyticalmethods for quality assurance. In addition, about 150 PET samples from 14 European recycling companies and
PET recyclate users were examined over a long time period. On top of that, the researchers quantified theamounts of acetaldehyde and limes which were present in all samples.
The samples were analysed using the following three different analytical methods:- gas chromatography headspace analysis,- high speed extraction followed by gas chromatography and- polymer extraction followed by gas chromatography.
The most suitable analytical method for quality assurance proved to be gas chromatography headspace analysis.
Using this method, even the smallest amounts of relevant migratory substances in the PET material could be
reliably detected. Compared to the two extraction methods, headspace analysis requires no sample preparation.
This simplifies the method and also considerably reduces the costs and time required. The new analytical methodfor quality assurance enables the operators of PET recycling plants to routinely monitor their recycling process.
The system is very robust and simple to operate. Within a few hours it provides data about the purity of the PET
recyclate. Using this knowledge about possible contaminants and their concentration levels, the existing PET
recycling processes can be optimised.

4. 2

Challenge-Tests for the Testing of the Cleaning Efficiency of Different
Recycling Processes

Due to modern environmental packaging requirements the recyclability of post-consumer PET-recyclate into
new food packaging applications is of increasing importance10. The recycling process and the quality assuranceof the PET-recyclate must satisfy special requirements. The Fraunhofer Institute IVV has developed challengetests for testing the cleaning efficiency of different recycling processes. These Challenge-Tests investigate if arecycler provides a PET-recyclate quality suitable for direct contact applications. For challenging a PETrecycling process for post-consumer soft-drink bottles post-consumer PET flakes are artificially contaminatedwith model contaminants or so called surrogates. In worst case scenarios misuse of PET-beverage bottles such as
storage of domestic chemicals and the possible introduction of these compounds into the recycling process is
s i m u l a t e d .
The surrogates are chemical substances with different chemical structures and different physical properties. They
are chosen such that they represent the four general categories of chemical compounds: volatile and non-polar,
volatile and polar, non-volatile and non-polar, non-volatile and polar. In addition a wide range of functionalgroups is used in order to reflect the different chemical and physical properties of real-life contaminants. In
contrast to FDA procedure IVV use no excessive solvents for the surrogates. Therefore the amount ofcontaminated waste is reduced and makes this Challenge-Test more user-friendly and economical.
Within the standards, measurements & testing programme (SMT4-CT96-2 129) Establishment of a standard test
procedure for refillable PET bottles with respect to chemical inertness behaviour as well as sensory interactivity
including preparation of a certified reference PET material one reduced set of model compounds (consisting of
propylene glycol, phenol, menthol, benzophenone, toluene, p-xylene, limonene and phenylcyclohexane) wast e s t e d 1 1 .

4. 3

Fair Project Recyclability12

Food packaging regulations in Europe require that the packaging materials must not cause mass transfer(migration) of harmful substances to the food. Considerable scientific progress has been made in understanding
and modelling the diffusion and migration of adventitious hazardous substances from recycled plastics into

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foodstuffs in direct or indirect contact with the food. Most of this knowledge has been elaborated within the
recently finished EU project AIR-CT93-I01413. One of the main conclusions of this project was that PET is alow diffusivity plastic and is the most promising polymer for reuse as a food packaging material. Furthermore,from the project's results and taking the existing FDA's position into account, for the first time in Europe an
attempt has been made within an International Life Sciences Institute (ILS1 Europe) expert group to draft
corresponding guidelines and recommendations for the safe reuse of plastics for food packaging.
Nevertheless, the practical translation of this progress into innovative industrial solutions is still awaited One of
the reasons has typical European character and can be substantiated by the fact that the European legal
requirements in this respect are not yet clearly and uniformly defined. As a consequence, the second reason is thelack of economic and generally recognised test methods.
With respect to PET, although being the most promising candidate plastic for recycling, there is clearly an
obvious reason for the industrial hesitation in launching advanced food packaging applications. In the wholechain of knowledge on diffusion and migration into and out of PET - which allows for instance to correlate aknown initial concentration in the plastic with the resulting time-dependent concentration in a foodstuff - there
remains one missing link: This is the still open but highly important question of the nature and concentration of
actual contaminants found in collected PET such as that originating from soft drink bottles. Filling up this gap
with analytical data relevant for the whole of Europe, and then linking this statistical picture with the available
knowledge on PET diffusion behaviour, would enable to draw scientifically sound and convincing conclusions
about the safety of reusing PET. This in turn would allow to derive the appropriate test conditions and methods
for industry to use and for recommending to the Commission for future regulations. These methods will offer for
the first time the possibility of being not too exaggerated and overchallenging - which is presently necessary as aprecaution due to the current lack of knowledge - but being practical and economical whilst safe-guarding theconsumer at the same time.
The objectives of the project are:
- To facilitate industrial innovation and to harmonise legislative enforcement of new environmental packaging
requirements stemming from the Directive 94/62/EEC on packaging and packaging waste, by- Drawing up a statistical overview of the nature and extent of contaminants in PET recovered from the foodpackaging market, in order to establish an evaluation platform for the quality and safety-in-use of recycled
PET plastics for food packaging and- Generating a scientific understanding of the physico-chemical behaviour of chemical contaminants on paperand board fibres as a basis for safety evaluation and definition of criteria for the appropriate reuse of recycledfibres for food packaging.

5

Life

Cycle

Assessment

The aim of a life cycle assessment is to highlight the negative impact which products have on the environment
from the time they are produced right through to the time they are disposed of and to analyse the associatedeffects of this impact with a view to creating a basis for assessing all types of products. In future, the life cycle
assessment will play an increasingly important role in the selection of packaging.
The Federal Environment Agency of Germany has had various life cycle assessments drawn up for packaging
systems and packaging materials. An initial assessment based on a comparison of recyclable and refillable
containers for beer and milk revealed that refillable systems are not fundamentally better than recyclable
packaging when longer distances are involved. 1 4-298-

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(1999)For the first time, life cycle assessments have been drawn up with a view to evaluating the methods used forrecycling post-consumer plastic packaging. A comparison of the different processes15 used in plastic recycling
has revealed that it is not one specific method, but rather a combination of feedstock recycling and mechanicalrecycling which is the most ecologically and economically sound solution.

5. 1

Bottles for Mineral Water

GDB (Genossenschaft Deutscher Brunnen) has ordered a LCA of PET and glass bottles for mineral water. The
Results are:Reflllable and Recyclable PET bottles16: Refillable bottles with 71 g and 25 turns as well as bottles with 56 g
and 1 5 turns are significant better than a 50 g bottle with 5 turns. Within the recyclable bottles the Supercycle
bottle with 50% recyclate and the multilayer bottle with 40% recyclate are better than usage of PET recyclate in
the textile industry.
Refillable PET and Glass Bottles17: 0.7-1-GDB and 1 -1-ODB glass bottles with 50 turns are at smaller transportdistances of I 10 km superior to the new 1-1-GDB PET bottle. At 180 km there is no significant difference and at
longer distances of300 km the PET bottle is ecologically better.

5.2

Vacuum Packed Roast Coffee

The Fraunhofer Institute for Process Engineering and Packaging IVV in Freising has presented the results of thefirst product life cycle assessment for coffee18,19. Within the framework of a study, the significant ecologicaleffects of the total life cycle of vacuum packed coffee were investigated. The work was commissioned by Kraft
Jacobs Suchard KJS together with the Senate of the free Hanse city Bremen.
The life cycle was balanced right from the cultivation and processing of the green coffee beans via the different
transport stages, roasting, packaging, wholesale and retail, the shopping journey, preparation for drinking andconsumption through to the disposal of the coffee grounds and the packaging.
One of the main points of attention was the comparison of the environmental effects of the packaging with thoseof the packaged product. We examined the current packagings Krönung and Monobag at KJS and also a
projected variant Monobag neu. The effect of different disposal scenarios for the used packagings was likewisetaken into account.
The assessment showed some surprising results. For example, it was shown that the transport and logistic
processes in the total assessment only contribute to a relatively small degree to the energy consumption andgreenhouse effects - although coffee is transported about half way around the world, namely up to a distance of
19,000 km. Relative to the total life cycle, the packagings which were examined also have little environmental
impact. On the other hand, the cultivation and preparation of the coffee, the roasting process, the preparation of
the coffee for drinking and the disposal of the coffee grounds all have clear effects.

6

Returnable or Refillable Packaging

Returnable (reusable or refillable) packaging is a type of packaging which, in contrast to one-way (nonrenurnable, single trip, disposable) packaging, is cleaned and used again as packaging. In Germany, thediscussion on returnabel and one-way packaging still exists because of the increase of cans and PET-bottles forcarbonated soft-drinks and mineral water. For different scenarios the above mentioned life cycle assessments
were published.
Nevertheless, efficient returnable packaging systems are as a rule environmentally superior to the disposable
alternatives. A high degree of standardisation can have positive effects: the use of packaging systems from

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packaging pools, e. g. the NRW-bottle for beer or the GdB-bottle for mineral water, leads to a higher circulation
rate, and secondly to the prevention of unnecessary long return journeys being made by empty items.

6. 1

Inspection of Refutable Bottles

To obey the regulations for product liability an empty bottle inspector is required with optimum detection
capability for glass bottles (finish, entire threads, inner surface, base, side-wall, scuffed bottles, residual liquid,etc.) and operational safety. So called sniffers were used for detecting undesirable foreign substances (e. g.
nitrogen compounds, volatile organic compounds, petrochemicals, and hydrocarbons) in empty plastic bottles

6. 1. 1

Empty Bottle Inspection Machines

After cleaning bottles must be clean and fit to use. Those bottles not being useable must be detected andremoved from the bottle stream before filling. The main faults are:- bottles with defects, e. g. in the mouth and bottom area, such as cracks, splits, chips, fins, etc.
- bottles containing foreign bodies, mould, pigment or other adhesive residues, metal pieces, plastic films,
s t r a w s ,- bottles containing residual caustic from the bottle washing machine or other liquids,- still dirty bottles.
Modem bottle inspectors operate with high speed CCD cameras with integrated analogue-digital converters andvery fast picture taking up to 40 μs (1/250,000 s). The inspection units which are nowadays used are: external
and interior side-wall inspection, bottom (base) inspection, neck finish (bottle mouth) inspection, threadinspection, metals in bottle, residual liquid detection with infrared inspection (caustic, water, acid, oil) and highfrequency radiation (traces of caustic), control of height, diameter, contour, colour, and especially for PET
hollies, stress cracking, impact scars, leakage, vent slots.
More details can be found in the following publications: COCA-COLA has published Approval procedures for All
Surface Empty Bottle Inspectors (ASEBI) and UNION OF EU SOFT DRINK ASSOCIATIONS (UNESDA) issued
Guidelines for good handling practices of refillable glass bottles.

6. 1. 2

Scuffing of Glass Bottles

Scuffing is the appearance of wear marks on glass bottles and plays an important role when filling especiallycarbonated beverages in returnable glass bottles20 ,21. In relation to different laws and standards for product safety(e. g. German Product Liability Law, ISO 9000, HACCP) it is important to know how the scuffing influences theproperties of glass bottles. Therefore some strength properties of differently scuffed bottles were tested. On theother hand scuffing is an unwanted appearance for the marketing of high quality products. There were madesome investigations on how the bottles become scuffed within the filling plant.

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Figure 3

Scheme of the test rig to detect and evaluate the wear mark area and the degree ofScuffing

The surface of glass bottles gets mechanically and chemically damaged when passing through bottling lines.
During their transport on conveyors or in individual machines within the bottling line the bottles get wear marks(scuffing) or even more severe surface injuries. On conveyors the bottles get mechanically scuffed especially bybottle-to-bottle pressure before glideliners, in combiners, accumulation tables and on the load of the bottle
washer and the inlet of the packer. Dirt and water on the glass surface of the bottles accelerates the mechanicaldamage! In further examinations it could also be shown that the technical standard and the arrangement of themachinery in a filling line as well influence the intensity of scuffing and therefore the theoretical circulation rate.
These effects are due tofrictionalforces between the bottles which are also enhanced with increasing scuffing.

-4!

F i g ur e 4

N R W b o t t le p o o l c o n d it io n s o f t h r e e G e r m a n b re w e r i e s ; p e r c e n t a g e of b ot t l e s e x c e e dinga defined wear mark height

The bottle surface additionally gets damaged by attacks by chemical action during the washing process. The
glass surface is injured and made more sensitive for mechanical stress. Certain detergents like caustic soda, freephosphates, and carbonates attack the surfaces. The effects are influenced by detergent concentration, water
hardness, exposure time, and temperature. There are some additives which can reduce the corrosive effect of thelye. But no significant further improvement can be expected because of the required cleaning effect.
The examinations on glass strength related to the degree of scuffing showed that the internal pressure stability
and the shock resistance of different shaped returnable glass bottles first decrease with an increasing wear mark-301-

Influence of the European and German Environment Legislation on the Food Packaging Tecknology in Germany

height or area. Then a stagnation of stability can be found for both characteristics with increasing degree ofscuffing.
The results from this study will help legislators or associations to determine criterions for guidelines andregulations with respect to consumer safety or bottle appearance.

Figure 5

Influence of the amount of scuffing on the internal pressure stability and the shock
ResistancePET Bottles Effect of Material Stress - Circulation Rates
The refillable system, with a cycle between bottling plant and consumer, inherently involves the question about
the technical suitability and the performance of bottles for beverages, which have been returned, cleaned andrefilled. Here, the aspect concerning the chemical inertness of the bottle material against filling with improper
substances and in addition the effect of material stress (number of cycles a bottle has been through) can beespecially named.

6. 1. 3

Sniffers for Plastic Bottles

Containers for packaging food and bottling beverages have to meet strict European Laws, which means that
nobody may be injured or get sick by using it. Returnable bottles have to be exactly inspected before filling22,
especially PET or PEN bottles made of polymer chains which build pores23. Therefore plastic bottles are notinert for beverages or other fluids. Some content substances of these fluids e. g. flavours can remain in pores oreven migrate further into the plastic material. By cleaning the bottles in the washing machine of a filling plantthese substances can remain in the bottle material. The substances may later on migrate back into the bottled
beverage.
It is particularly a problem when tilling a sensible beverage like mineral water without a taste in used plastic
bottles. The flavours of other beverages can severely influence the taste of the water. Most of the bottlers ofmineral water either have individual bottles, or use only new plastic bottles (one-way or returnable only the firsttime). Some consumers even put other liquids in the plastic containers like oil, fuel or washing detergents.
When using returnable plastic bottles these substances have to be detected and dirty bottles have to be removed.
Most of the foreign flavours of before filled beverages or other fluids from the consumers can be inspected bysmell or analyse of the residual liquid.
A sniffer has to be placed right after a decapper, often the latter is integrated into the sniffer. It is important tosniff the bottle immediately after decapping because some smells fade away quickly. Most of the sniffers aredesigned as carousel-machines (rotary-, roundabout-machines). Three or four detection units inspect the gas
phase for volatile substances and the remaining fluid phase. A gas sample is taken and analysed in different

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modules, e. g. by mass spectroscopy sometimes in addition with chemical or electrical ionisation, UV/VIS- andIR-spectroscopy, and measuring the luminescence (fluorescence, phosphorescence, chemoluminescence). The
remaining liquid phase is also analysed by spectroscopy methods using the bottle as a test tube by tipping thebottle to one side. The analyses are time extensive but now, up to 50.000 bottles per hour depending on the bottle
size can be inspected. A scheme of a sniffer and its inspection modules is shown below.
Most sniffers employ the positive measuring method, which means comparing the measured spectrums of gas
and liquid phase with the fingerprints of specific beverage flavours stored in a library. If the detected spectrum isin the positive library, the bottle is accepted. If the spectrum is not known the bottle is rejected. The systems areable to learn new fingerprints by adding them to the library, e. g. when a new product is filled in the plant. The
detection methods are not completely reliable, but by using a positive library good results can be achieved.
There could be two or more outlets to split the rejected bottles into groups: e. g. detecting a known flavour oforange to fill a flavoured drink and bottles with unknown spectrums for recycling. Additionally some otherinspection modules like testing for leak or geometric distortion could be integrated in a sniffer. The following
suppliers are well known: KHS/Grässle, D-Dortmund; Krones/Thermedics Detection, D-Neutraubling;
Soudronic, CH-Bergdietikon.

6. 2

PET-bottles for beverages

The use of PET (polyethylene terephthalate) as a material for packaging is increasing all over the world. In thearea of refillable bottles for soft drinks, PET is already established as a packaging material due to its properties.
Its use is still increasing, especially for the bottling of mineral water. It is expected that new developments suchas PEN (polyethylene naphthalenate) will force their way into the beer bottle market in the near future withprobable good chances of success.

6. 2. 1

Usability of PET Bottles for Beer

At my chair several investigations has been carried out to study the field Polyester Bottles for Beer. We installeda working group with partners of different branches of industry: brewery, bottle and closure producer, chemicalindustry and filler manufacturer. First aim of the project was to find a refillable plastic bottle which is able toguarantee a shelf life of beer of four month at minimum. In the meantime some breweries are filling beer into
one-way bottles, so our research will be extended to one-way plastic bottles and their properties, too.
Table 4

Examples of plastic bottles sold in the market-303-

Influence of the European and German Environment Legislation on the Food Packaging Technology in Germany

At the beginning of the project the influence of the washing temperature and concentration of cleaning agent(caustic) to the form stability of the PET bottles which included the measurement of height and volume of thebottles before and past cleaning with caustic solution was examined (Figure 6). In addition, we studied theinfluence of caustic to the barrier properties of PET bottles.

Figure 6

Influence of cleaning temperature to brimful volume of PET and PET/PEN high level copolymer
bottles

Furthermore investigations were made on the shelf life of beer in polyester bottles. Therefore beer was filled into
glass bottles (as reference) and into plastic bottles. The applied plastic bottles consisted of 100% PEN. After astorage under different conditions the ageing components of the beer were determined by GC-analysis. Also
comparative sensory evaluations, so called tasting of the beer has been taken place. The aim of these studies wasto compare the theoretically, computed shelf life calculate by the results of permeation measurement to the real,measured shelf life of the stored beer. The results of these examinations showed that the real oxygen penetration
into the plastic bottles differs to the calculated one.
Further a detailed literature survey about the topic Ageing of beer and beer flavour stability24 was appointed. It
was purposed to prepare the investigation of the technological possibilities to improve beer flavour stability andtheir effects on shelf life during storage. Additionally we made some trials in producing beer with different
methods of beer stabilisation. Therefore several beers were produced and the flavour stability was examined byanalysing the ageing components and tasting the beer.
Ageing components of beer are smell- and flavour-active carbonyl compounds. To measure ageing of beer thesum of ageing-components of beer can be used as a characteristic value. It correlates with the intensity of thetasted ageing-aroma. Ageing components of beer are analysed with a GC-method. The average content of ageing
components in fresh beer is about 90 ppm.
Following substances belong to the ageing-components: Succinic acid diethyl ester, 2-methyl-butanal, 3-methylButane*), benzaldehyde*), phenylacetaldehyde, 2-furfural, 5-methy1-2-furfural, γ-nonalactone, phenylethanal*).
The*) marked substances can be detected in a higher amount in case of an enhanced oxygen intake in the beer.
During ageing of beer the following changes occur: Loss of palatfulness and of bitterness, changes of aroma
profiles. The increase of ageing components correlate with changes in smell and flavour. The flavour
impressions are: ribes-flavour, cardboard-flavour, bread or cracker like, caramel or honey like. If beer isextremely old it smells like sherry.
Furthermore we investigated several bottle types concerning to their permeation and migration properties(Figure 7). To study the permeation properties we tested permeation with the MOCONⒸ OxTran O2-permeation
meter. An other method of measuring O2-permeation was to fill the bottles with degassed water and to measure-304-

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the permeating O2 with an DIGOX O2-meter. During this experiment the filled bottles were stored under
different conditions (normal conditions, increased temperature, increased O2 partial pressure). The intention was
to compare the oxygen uptake into the empty bottle and the filled bottle. Additional to this another objective of
this experiment was to predict shelf life of defined beer in short term trials. For that purpose we stored beer inthe same type of bottle and investigated shelf life by analysing ageing components and tasting. Since the ageingof beer correlates with the O2-contents of the beer it should be possible to predict shelf life of beer by measuring
O 2 -increase into the bo ttle.

Figure 7

Oxygen-permeation of different bottle types (Volume 0. 5 liter)

To achieve a long shelf life of the beer the polyester bottle should have following properties:- The ingress of oxygen should be very low- The loss of CO 2 should not increase 10%- The UV-transmission rate should be very small- Acetic aldehyde does not influence the taste of beer.
The migration of aroma compounds and ageing components was studied with different bottle types. The bottles
were cleaned with caustic different times to simulate a varying number of cleaning cycles followed by the fillingof the bottles and the storage under various conditions. Past storing the bottles the beer was rejected and thebottles were cleaned another time. Some of the bottles were cleaned again with caustic, the rest of the bottles
were cleaned with tap water. The aim of these trials was to show if there is any migration of beer aroma
compounds and ageing components of beer into the bottle walls and to test their sensitivity concerning thecleaning with caustic.

6. 2. 2Future Technologies

Multilayer Bottles with Liquid Crystal Polymers
Superex Polymer, Inc. invented a new multilayer technology25. They used Liquid Crystal Polymers (LCP)
instead of other barrier liners such as EVOH or MXD6. The advantages of the LCPs are their low costs and highbarrier performance. The performance of LCP-PET multilayer is not affected by moisture and it is possible toincrease the shelf life of the product at equivalent costs compared to other multilayer solutions. A disadvantageof the LCPs is their opacity. But Superex believes in the possibility to make transparent LCPs in the future.

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Influence of the European and German Environment Legislation on the Food Packaging Tecknology in Germany

Interior Coating - ACTIS Plasma Technology by SIDEL 26
On April 1999 the French Company Sidel presented its new ACTIS (Amorphous Carbon Treatment on Internal
Surface) process. It endows PET packages with unmatched barrier properties. The company clame to be able toincrease the Oxygen barrier properties 30 times compared to traditional, single layer PET bottles, and the CO2,
barrier is supposed to be seven times stronger. Thus the PET bottles' barrier properties would be comparable toglass bottles and metal drink cans.
The process consists of coating the inside of a standard, single layer PET bottle with a layer of highlyhydrogenated amorphous carbon, obtained from a food safe gas in its plasma state. This coating creates a thin(about 1/10th micron thick) barrier inside the bottle. Its food safe quality has been approved by TNO in the
Netherlands and the treated bottle is 100% recyclable.
Plasma treatment is performed by a machine located downstream from the PET blow-molding machine. Its
design is based on Sidel's proven rotary, high output rate technology. The first model of this new technique isknown as ACTIS 20, and both process and technology are protected by Sidel patents. The ACTIS machine isequipped with 20 stations, and treats 10,000 PET bottles per hour for container sizes up to 0.6 1.

Exterior Coating
Amcor & Foster 's Brewing Group sold the worlds first commercial barrier coated beer bottle27. The bottles theyused to fill Carlton Cold Filtered beer were 400 ml clear PET bottles with a 50 mm champagne base withexternal epoxy amine coating by PPG. It is sold as a single serve container but it should be easy to recycle,

7

L i t e r a t u r e

1)
2)
3)

Duales System Deutschland AG, Köln: http://www.gruener-punkt.de/e/index.htm
Gesellkschaft für Konsumforschung (GfK), Nürnberg, 1999: http://www.gfk.cube.net
European Parliament and Council Directive 94/62/EC of 20 December 1994 on Packaging and Packaging
Waste. Official J. European Communities L365 , 31/12/1994, p. 10-23
4) Waste Avoidance, Recycling and Disposal Act of 27 September, 1994 BGB1 I p 2705
(Kreislaufwirtschafts- und Abfallgesetz – KrWV-AbfG) modified of 7 October 1996, BGB1. I p. 1354
5) Ordinance on the Avoidance and Recovery of Packaging Waste (Packaging Ordinance Verpackungsverordnung - VerpackV) 21 August, 1998, BGB1I, p. 2379
6) http : //www. gruener-punkt. de/e/co ntent/daten/pm99 0708. htm
7) Ohl Apparatebau & Verfahrenstechnik, Limburg: http://www.ecotechnikum.net
8) Schmalbach - Lubeca, Ratingen : http : //www.Schmalbach. com/investoren/iv_fue_l. him9) http://www.rosbacher.com/pet.htm10) Welle, F.; Franz, R: PET-Recyclate for Food Packaging. In Barrage, A.; Edelmann, X. (Eds..)/EMPA- R'99
Recovery, Recycling, Re-integration. Collected Papers of the R'99 World Congress. Geneva Switzerland
February 2-5, 1 999. Volume III: Logistics-Network - Identification and Separation. Mechanical Recycling- Product Design - Eco Design Innovation. St. Gallen: EMPA, 1999, S. 514-517
11) Palzer, G.; Franz, R: Chemische Inertheit von PET-Getränkemehrwegflaschen. Testmethode zur
Bestimmung der Inertheit und somit Beschaffenheit des PET-Flaschenmaterials. Kunststoffe 88 (1998) Nr.
6 , S . 8 6 2 - 8 6 512) http://www.ivv.fhg.de/fair/index.html

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13) EU-Project AIR2-CT93-1014: Working group 2. Mechanical Recycling (Thermoplastics). Final Report,
November 1997
14) German Federal Environmental Agency: http ://www. umweltbundesamt.de/uba-info-e/e-willko.htm
15) Heyde, M.; Kremer, M.: Recycling and Recovery of Plastics from Packagings in Domestic Waste. LCAType Analysis of Different Strategies. Bayreuth: Eco-lnforma Press, 1999. ISBN 3-928379-57-7, 194 S. a.
appendix (LCA Documents 5)16) Plinke, E.: Ökologische Bilanzierung von Mehrweg- und Einweg-PET-Flaschen. Der Mineralbrannen 49(4), 124-129 (1999)17) Plinke, E.: Ökologische Bilanzierung von PET- und Glasflaschen für Mineralwasser. Der Mineralbrunnen
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