Safety assessment of the process Starlinger viscotec viscoZERO PET used to recycle post‐consumer PET into food contact materials

Abstract

The EFSA Panel on Food Contact Materials (FCM) assessed the safety of the recycling process Starlinger viscotec viscoZERO PET (EU register number RECYC340). The input is hot washed and dried poly(ethylene terephthalate) (PET) flakes mainly originating from collected post‐consumer PET containers, with no more than 5% PET from non‐food consumer applications. The flakes are melted in an extruder (step 1) and decontaminated in a reactor under high temperature and vacuum (step 2). In step 3, the melt is transferred out of the reactor and cooled down. Having examined the challenge test provided, the Panel concluded that the extrusion (step 1) and the treatment in the viscoZERO reactor (step 2) are critical for the decontamination efficiency of the process. The operating parameters to control the performance are the temperature for step 1, and for step 2, the pressure, the temperature as well as the decontamination index, interconnecting the rotation speed, the geometrical parameters and the throughput. It was demonstrated that this recycling process ensures that the level of migration of potential unknown contaminants into food is below the conservatively modelled migration of 0.0481 or 0.0962 μg/kg food, depending on the molar mass of a contaminant substance. Therefore, the Panel concluded that the recycled PET obtained from this process is not of safety concern, when used at up to 100% for the manufacture of materials and articles for contact with all types of foodstuffs, including drinking water, and used for long‐term storage at room temperature or below, with or without hot‐fill. Articles made of this recycled PET are not intended to be used in microwave and conventional ovens and such uses are not covered by this evaluation.

1. INTRODUCTION

1.1. Background

Recycled plastic materials and articles shall only be placed on the market if the recycled plastic is from an authorised recycling process. Before a recycling process is authorised, the European Food Safety Authority (EFSA)'s opinion on its safety is required. This procedure has been established in Articles 17 and 18 of Commission Regulation (EU) 2022/1616 ¹ on recycled plastic materials intended to come into contact with foods. More specifically, according to Article 18 of Commission Regulation (EU) 2022/1616 on recycled plastic materials intended to come into contact with foods, EFSA is required to carry out risk assessments on the risks originating from the migration of substances from recycled food contact plastic materials and articles into food, to evaluate the microbiological safety of these materials and articles and to deliver a scientific opinion on the recycling process examined.

According to this procedure, the process developers submit applications to the competent authorities of Member States, which transmit the applications to EFSA for evaluation. In this case, EFSA received an application from the Austrian Competent Authority (Bundesministerium für Soziales, Gesundheit, Pflege und Konsumentenschutz), for evaluating the recycling process Starlinger viscotec viscoZERO PET, European Union (EU) register No RECYC340. The request has been registered in the EFSA's register of received questions under the number EFSA‐Q‐2023‐00496. The dossier was submitted on behalf of Starlinger & Co. GmbH, Division viscotec, Adsdorf 38, 4113 St. Martin im Mühlkreis, Austria (see ‘Documentation provided to EFSA’).

1.2. Terms of Reference

The Austrian Competent Authority (Bundesministerium für Soziales, Gesundheit, Pflege und Konsumentenschutz), requested the safety evaluation of the recycling process Starlinger viscotec viscoZERO PET, in compliance with Article 17 of Commission Regulation (EU) 2022/1616. The recycling process uses the recycling technology number 1 of the list of suitable recycling technologies of Table 1 of Annex 1 of Commission Regulation (EU) 2022/1616.

2. DATA AND METHODOLOGIES

2.1. Data

The applicant submitted a confidential and a non‐confidential version of a dossier, following EFSA's ‘Scientific Guidance on the criteria for the evaluation and on the preparation of applications for the safety assessment of post‐consumer mechanical PET recycling processes intended to be used for manufacture of materials and articles in contact with food’ (EFSA CEP Panel, 2024) and EFSA's ‘Administrative guidance for the preparation of applications for the authorisation of individual recycling processes to produce recycled plastics materials and articles intended to come into contact with food’ (EFSA, 2024).

Additional information was received from the applicant during the assessment process, in response to requests from EFSA sent on 23 March 2024, 28 January 2025 and 21 October 2025 (see ‘Documentation provided to EFSA’). A technical hearing was held with the applicant on 15 January 2025. ²

In accordance with Art. 38 of the Regulation (EC) No 178/2002 ³ and taking into account the protection of confidential information and the personal data in accordance with Articles 39 to 39e of the same Regulation, and of the Decision of the EFSA's Executive Director laying down practical arrangements concerning transparency and confidentiality, ⁴ the non‐confidential version of the dossier has been published on Open.EFSA. ⁵

According to Art. 32c(2) of Regulation (EC) No 178/2002 and to the Decision of EFSA's Executive Director laying down the practical arrangements on pre‐submission phase and public consultations⁴, EFSA carried out a public consultation on the non‐confidential version of the application from 6 September to 27 September 2024, for which no comments were received.

The following information on the recycling process was provided by the applicant and used for the evaluation (EFSA, 2024; EFSA CEP Panel, 2024):

• –Recycling process,
• –Determination of the decontamination efficiency of the recycling process,
• –Table of operating parameters,
• –Self‐evaluation of the recycling process.

2.2. Methodologies

The risks associated with the use of recycled plastic materials and articles in contact with food come from the possible migration of chemicals into the food in amounts that would endanger human health. The quality of the input, the efficiency of the recycling process to remove contaminants as well as the intended use of the recycled plastic are crucial points for the risk assessment (EFSA CEP Panel, 2024).

The criteria for the safety evaluation of a mechanical recycling process to produce recycled PET intended to be used for the manufacture of materials and articles in contact with food are described in the scientific guidance developed by the EFSA Panel on Food Contact Materials, Enzymes and Processing Aids (EFSA CEP Panel, 2024). The principle of the evaluation is to apply the decontamination efficiency of a recycling process, obtained from a challenge test with surrogate contaminants, to a reference contamination level for post‐consumer PET, conservatively set at 3 mg/kg PET for contaminants resulting from possible misuse. The resulting residual concentration of each surrogate contaminant in recycled PET (C_res) is compared with a modelled concentration of the surrogate contaminants in PET (C_mod). This C_mod is calculated using generally recognised conservative migration models so that the related migration does not give rise to a dietary exposure exceeding 0.0025 μg/kg body weight (bw) per day (i.e. the human exposure threshold value for chemicals with structural alerts for genotoxicity), below which the risk to human health would be negligible, considering different dietary exposure scenarios (EFSA CEP Panel, 2024). If the C_res is not higher than the C_mod, the recycled PET manufactured by such recycling process is not considered of safety concern for the defined conditions of use (EFSA CEP Panel, 2024).

The assessment was conducted in line with the principles described in the EFSA Guidance on transparency in the scientific aspects of risk assessment, considering the relevant guidance from the EFSA Scientific Committee (EFSA, 2009).

3. ASSESSMENT

3.1. General information ⁶

According to the applicant, the recycling process Starlinger viscotec viscoZERO PET is intended to recycle food grade PET containers. The recycled PET is intended to be used at up to 100% for the manufacture of materials and articles for direct contact with all kinds of foodstuffs, such as bottles for mineral water, soft drinks, juices and beer. The final articles are intended for long‐term storage at room temperature or below, with or without hot‐fill. The final articles are not intended to be used in microwave or conventional ovens.

3.2. Description of the process

3.2.1. General description ⁷

The recycling process Starlinger viscotec viscoZERO PET produces recycled PET from PET materials originating from post‐consumer collection systems.

Input

• In step 0, the post‐consumer PET is processed into hot washed and dried flakes.

Decontamination and production of recycled PET material

• In step 1, the flakes are extruded.

• In step 2, the melt is decontaminated in the viscoZERO reactor.

• In step 3, the melt is cooled down and pelletized or processed into final articles.

The operating conditions of the process have been provided to EFSA.

3.2.2. Characterisation of the pre‐processed plastic input ⁸

According to the applicant, the input material consists of hot washed and dried flakes obtained from PET materials, e.g. bottles, previously used for food packaging, from post‐consumer collection systems. A small fraction may originate from non‐food applications. According to the applicant, the proportion will be no more than 5%, as specified in Article 7 and Table 1 of Annex I of Commission Regulation (EU) 2022/1616.

TABLE 1.

Efficiency of the decontamination of the Starlinger viscotec viscoZERO PET process in the challenge test.

Surrogates	Concentration of surrogates before step 1 (mg/kg PET)	Concentration of surrogates after step 3 (mg/kg PET)	Decontamination efficiency (%)
Toluene	511.0	< 0.3 a	> 99.9
Chlorobenzene	719.0	< 0.8 a	> 99.9
Phenylcyclohexane	665.0	< 0.8 a	> 99.9
Benzophenone	752.0	< 2.6 b	> 99.7
Methyl stearate	826.0	< 4.0 b	> 99.5

^a Not detected at the limits of detection given.

^b Below the limit of quantification.

Technical specifications on the hot washed and dried flakes are provided, such as on physical properties and residual contents of moisture, poly(vinyl chloride) (PVC), polyamide (PA), polycarbonate (PC), other plastics, wood and paper, glue and metals (see Appendix A).

3.3. Starlinger viscotec viscoZERO PET process

3.3.1. Description of the main steps ⁹

The process flow diagram, as provided by the applicant, is reported in Figure 1. The steps are:

• Extrusion (step 1): The flakes are melted in an extruder and transferred to the reactor of step 2.

• Decontamination in the viscoZERO reactor (step 2): The melt is decontaminated under high temperature and vacuum in a continuous reactor. ■■■■■ By passing through the mixing elements, the melt surface area is renewed for decontamination. Finally, the material reaches a discharge screw and is pumped out of the reactor.

• Processing of the melt (step 3): The melt material is cooled down and pelletised or transferred to a downstream equipment, such as a sheet extruder or injection press.

FIGURE 1.

Process flow diagram of the Starlinger viscotec viscoZERO PET process (provided by the applicant).

The process is run under defined operating parameters ¹⁰ of temperature, pressure, rotation speed, filling level and throughput. All critical parameters are automatically monitored via a relevant software. Any deviation leads to an alarm and rejection of the material. ¹¹

According to the applicant, the final product of the process (pellets, sheet or preforms) are checked against technical requirements, such as intrinsic viscosity, size, filtration and bulk density. ¹²

3.3.2. Decontamination efficiency of the recycling process ¹³

To demonstrate the decontamination efficiency of the recycling process Starlinger viscotec viscoZERO PET, a challenge test performed at industrial scale on steps 1 and 2 was submitted to EFSA.

PET flakes were contaminated with toluene, chlorobenzene, phenylcyclohexane, benzophenone and methyl stearate, selected as surrogates in agreement with the EFSA Scientific Guidance (EFSA CEP Panel, 2024) and in accordance with the recommendations of the US Food and Drug Administration (FDA, 2021).

A batch of ■■■■■ kg PET flakes was divided into 10 barrels of ■■■■■ kg flakes each, to which a mixture of ■■■■■ g of each surrogate was added. The barrels were kept at ■■■■■°C for ■■■■■ days with periodical agitation. The contaminated flakes were then hot washed.

The decontamination efficiency was calculated from the concentration differences of the surrogate substances in the flakes sampled before the extrusion (step 1) and in pellets after processing of the melt (step 3). When surrogates were not detected, the limit of detection was considered for the calculation of the decontamination efficiency. The results are summarised in Table 1.

3.4. Discussion

Considering the high temperatures used during the process, the possibility of contamination by microorganisms can be discounted. Therefore, this evaluation focuses on the chemical safety of the final product.

Specifications on the input material (i.e. washed and dried flakes, step 0) are listed in Appendix A.

The flakes are produced from PET containers, e.g. bottles, previously used for food packaging, collected through post‐consumer collection systems. However, a small fraction may originate from non‐food applications, such as bottles for soap, mouthwash or kitchen hygiene agents. According to the applicant, the collection system and the sorting are managed in such a way that this fraction will be no more than 5% in the input stream, as recommended by the EFSA CEP Panel in its Guidance (EFSA CEP Panel, 2024).

The process is adequately described. The Starlinger viscotec viscoZERO PET process comprises the extrusion (step 1), decontamination in the viscoZERO reactor (step 2), and pelletisation or transfer to a downstream equipment (processing of the melt, step 3).

A challenge test to measure the decontamination efficiency was conducted at industrial scale on process steps 1 to 3. The Panel considered that it was performed correctly according to the recommendations of the EFSA Guidance (EFSA CEP Panel, 2024). The extrusion (step 1) and the decontamination of the material in the viscoZERO reactor (step 2) are critical and depend on the temperature of the extrusion for step 1, and on the surface area of the melt exposed to the vacuum per mass, the residence time, the pressure and the temperature for step 2. Consequently, the temperature of the extruder (step 1), and the pressure, the temperature as well as the interconnection among the rotation speed, the geometrical parameters and the throughput of step 2, as specified in the table of operational parameters (Appendix C), are to be controlled to guarantee the efficiency of the decontamination.

The Panel noted that the challenge test was performed on the smaller of two industrial decontamination installations. Based on the model provided by the applicant interrelating the surface area exposed to vacuum, mass of melt, residence time and the rotating speed of the shafts, the challenge test was considered representative for the process performed with installations of different sizes.

The decontamination efficiencies obtained for each surrogate, ranging from above 99.5% to above 99.9%, have been used to calculate the residual concentrations of potential unknown contaminants in PET (C_res). By applying the decontamination efficiency percentage to the reference contamination level of 3 mg/kg PET, the C_res values shown in Table 2 were obtained.

TABLE 2.

Decontamination efficiencies from the challenge test, residual concentrations of the surrogates (C_res) related to the reference contamination level and calculated concentrations of the surrogates in PET (C_mod) corresponding to a modelled migration of 0.0481 μg/kg or 0.0962 μg/kg after 1 year at 25°C (C_mod).

Surrogates	Decontamination efficiency (%)	Cres for 100% rPET (mg/kg PET)	Cmod (mg/kg PET) scenario A
Toluene	> 99.9	< 0.002	0.04
Chlorobenzene	> 99.9	< 0.003	0.05
Phenylcyclohexane	> 99.9	< 0.004	0.13
Benzophenone	> 99.7	< 0.010	0.15
Methyl stearate	> 99.5	<0.014	0.29

Abbreviation: rPET, recycled poly(ethylene terephthalate).

According to the evaluation principles (EFSA CEP Panel, 2024), the dietary exposure must not exceed 0.0025 μg/kg bw per day, below which the risk to human health is considered negligible. The C_res value should not exceed the modelled concentration in PET (C_mod) that, after 1 year at 25°C, results in a migration giving rise to a dietary exposure of 0.0025 μg/kg bw per day. As the recycled PET is intended for the manufacturing of articles (e.g. bottles) to be used in direct contact with drinking water, the exposure scenario for infants has been applied for the calculation of C_mod (Exposure Scenario A; water could be used to prepare infant formula). A maximum dietary exposure of 0.0025 μg/kg bw/day corresponds to a maximum migration of 0.0481 μg/kg (= 5 × 0.00962 μg/kg) or 0.0962 μg/kg (= 10 × 0.00962 μg/kg), depending on the molar mass of a contaminant substance ¹⁴ into infant's food and has been used to calculate C_mod (EFSA CEP Panel, 2024). C_res reported in Table 2 is calculated for 100% recycled PET. The results of these calculations are shown in Table 2. The relationship between the key parameters for the evaluation scheme is reported in Appendix B.

On the basis of the provided data from the challenge test and the applied conservative assumptions, the Panel considered that under the given operating conditions the recycling process Starlinger viscotec viscoZERO PET is able to ensure that the level of migration of unknown contaminants from the recycled PET into food is below the conservatively modelled migration of 0.0481 or 0.0962 μg/kg, depending on the molar mass of a contaminant substance into infant's food. At this level, the risk to human health is considered negligible when the recycled PET is used at up to 100% to produce materials and articles intended for contact with all types of foodstuffs, including drinking water (exposure scenario A), and used for long‐term storage at room temperature or below, with or without hot‐fill.

4. CONCLUSIONS

The Panel considered that the process Starlinger viscotec viscoZERO PET is adequately characterised and that the main steps used to recycle the PET flakes into decontaminated PET pellets have been identified. Having examined the challenge test provided, the Panel concluded that the extrusion (step 1) and the viscoZERO reactor (step 2) are critical for the decontamination efficiency. The parameters to control the process performance are the temperature for step 1, and for step 2, the pressure, the temperature as well as the decontamination index, interconnecting the rotation speed, the geometrical parameters and the throughput, as specified in the table of operational parameters (Appendix C).

The Panel concluded that the process is capable of reducing contamination of post‐consumer food contact PET to a concentration that does not give rise to concern for a risk to human health if:

1. it is operated under conditions that are at least as severe as those applied in the challenge test used to measure the decontamination efficiency of the process;

2. the input material of the process is washed and dried post‐consumer PET flakes originating from materials and articles that have been manufactured in accordance with the EU legislation on food contact materials and contain no more than 5% of PET from non‐food consumer applications;

3. the recycled PET obtained from the process is used at up to 100% for the manufacture of materials and articles for contact with all types of foodstuffs, including drinking water, for long‐term storage at room temperature or below, with or without hot‐fill.

The final articles made of this recycled PET are not intended to be used in microwave and conventional ovens and such uses are not covered by this evaluation.

5. RECOMMENDATION

The Panel recommended periodic verification that the input to be recycled originates from materials and articles that have been manufactured in accordance with the EU legislation on food contact materials and that the proportion of PET from non‐food consumer applications is no more than 5%. This adheres to good manufacturing practice and the Commission Regulation (EU) 2022/1616. Critical steps in recycling should be monitored and kept under control. In addition, supporting documentation should be available on how it is ensured that the critical steps are operated under conditions at least as severe as those in the challenge test used to measure the decontamination efficiency of the process.

6. DOCUMENTATION PROVIDED TO EFSA

Dossier ‘Starlinger viscotec viscoZERO PET’. November 2023. Submitted on behalf of Starlinger & Co. GmbH, Division viscotec., Austria.

Additional information, November 2024. Submitted on behalf of Starlinger & Co. GmbH, Division viscotec., Austria.

Additional information, September 2025. Submitted on behalf of Starlinger & Co. GmbH, Division viscotec., Austria.

Additional information, November 2025. Submitted on behalf of Starlinger & Co. GmbH, Division viscotec., Austria.

ABBREVIATIONS

bw

body weight

CEP

Panel on Food Contact Materials, Enzymes and Processing Aids

C_mod

modelled concentration in PET

C_res

residual concentration in PET

FCM

Panel on Food Contact Materials

PA

polyamide

PC

polycarbonate

PET

poly(ethylene terephthalate)

PS

polystyrene

PVC

poly(vinyl chloride)

REQUESTOR

Austrian Competent Authority (Bundesministerium für Soziales, Gesundheit, Pflege und Konsumentenschutz)

QUESTION NUMBER

EFSA‐Q‐2023‐00496

COPYRIGHT FOR NON‐EFSA CONTENT

EFSA may include images or other content for which it does not hold copyright. In such cases, EFSA indicates the copyright holder and users should seek permission to reproduce the content from the original source.

PANEL MEMBERS

Claude Lambré, Riccardo Crebelli, Maria da Silva, Koni Grob, Evgenia Lampi, Maria Rosaria Milana, Marja Pronk, Gilles Rivière, Mario Ščetar, Georgios Theodoridis, Els Van Hoeck, Nadia Waegeneers.

WAIVER

In accordance with Article 21 of the Decision of the Executive Director on Competing Interest Management a waiver was granted to an expert of the Working Group. Pursuant to Article 21(6) of the aforementioned Decision, the concerned expert was allowed to take part in the preparation and discussion of the scientific output but was not allowed to take up the role of rapporteur within that time frame. Any competing interests are recorded in the respective minutes of the meetings of the FCM Panel Working Group on Recycling Plastics.

LEGAL NOTICE

Relevant information or parts of this scientific output have been blackened in accordance with the confidentiality requests formulated by the applicant pending a decision thereon by EFSA. The full output has been shared with the European Commission, EU Member States (if applicable) and the applicant. The blackening may be subject to review once the decision on the confidentiality requests is adopted by EFSA and in case it rejects some of the confidentiality requests.

APPENDIX A. Specifications of the pre‐processed input material^* as provided by the applicant⁸.

Parameter	Value
Bulk density	250–750 kg/m3
Flake size	1–15 mm
Flake thickness	50–2000 μm
Moisture	< 2%
PVC	< 100 mg/kg
PC	< 50 mg/kg
PA	< 200 mg/kg
Other Plastics (e.g. PS, except PA, PC, PET & PVC)	< 500 mg/kg
Flakes with glue	< 4000 mg/kg
Wood, paper	< 100 mg/kg
Metals (Aluminium, ferrous, others)	< 500 mg/kg
Total contamination other than water	< 2000 mg/kg

Abbreviations: PA, polyamide; PC, polycarbonate; PS, polystyrene; PVC, poly(vinyl chloride).

^*Foreign plastics in the flakes were determined by ‘oven testing’.

APPENDIX B. Relationship between the key parameters for the evaluation scheme, based on the most conservative scenario A (EFSA CEP Panel, 2024)

*Depending on the molecular mass of the surrogate substance. The figures are derived from the application of the human exposure threshold value of 0.0025 μg/kg bw per day applying the factors of 5 and 10 related to the overestimation of modelling (most conservative Scenario A).

APPENDIX C. Table of operational parameters ¹⁵

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■■■■■

■■■■■

	Process Starlinger viscotec viscoZERO PET (RECYC340)
	Step 1 (Extrusion)			Step 2 (viscoZERO reactor)
	t (min)	P (mbar)	T (°C)	t * (min)	P (mbar)	T (°C)	Rotating speed* (rpm)	Decontamination index ■■■■■** ■■■■■
Challenge test (Report p2501525_27268K)	–	–	■■■■■	■■■■■	■■■■■	■■■■■	■■■■■	■■■■■
	Continuous			Continuous
Process viscoZERO 600	–	–	■■■■■	■■■■■	■■■■■	■■■■■	■■■■■	■■■■■
Process viscoZERO 1500	–	–	■■■■■	■■■■■	■■■■■	■■■■■	■■■■■	■■■■■
	Continuous			Continuous

^*Depending on line output ■■■■■

^{■■■■■}■■■■■

■■■■■	${\rho }_A=\frac{m_R}{\left(A_{\mathit{me}}\cdot n_m\cdot t\right)}$
■■■■■	$\text{Total generated surface}=A_{\mathit{me}}\cdot \frac{n_1+n_2}{2}\cdot t=A_{\mathit{me}}\cdot n_m\cdot t$

■■■■■

■■■■■

■■■■■

■■■■■

■■■■■

■■■■■

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*Characteristics of the reactors in the challenge test and the industrial process

	ViscoZERO 600 (challenge test and industrial process)	ViscoZERO 1500 (industrial process)
Throughput max. (kg/h)	■■■■■	■■■■■
Net capacity (m3)	■■■■■	■■■■■
Reactor filling (%)	■■■■■	■■■■■
Reactor length (m)	■■■■■	■■■■■
Reactor diameter (m)	■■■■■	■■■■■
Inner surface A me (dm2)	■■■■■	■■■■■
Rotation speed of the mixing elements (rpm)	■■■■■	■■■■■

EFSA FCM Panel (EFSA Panel on Food Contact Materials) , Lambré, C. , Crebelli, R. , da Silva, M. , Grob, K. , Milana, M. R. , Pronk, M. , Rivière, G. , Ščetar, M. , Theodoridis, G. , Van Hoeck, E. , Waegeneers, N. , Dudler, V. , Papaspyrides, C. , Tavares Poças, M. d. F. , Lioupis, A. , Lübke, A. , Tsochatzis, E. , & Lampi, E. (2026). Safety assessment of the process Starlinger viscotec viscoZERO PET used to recycle post‐consumer PET into food contact materials. EFSA Journal, 24(2), e9935. 10.2903/j.efsa.2026.9935