Safety assessment of the process Utsumi, based on the EREMA Basic technology, used to recycle post‐consumer PET into food contact materials

Abstract

The EFSA Panel on Food Contact Materials, Enzymes and Processing Aids (CEP) assessed the safety of the recycling process Utsumi (EU register number RECYC232), which uses the EREMA Basic technology. The input material is hot caustic washed and dried poly(ethylene terephthalate) (PET) flakes originating from collected post‐consumer PET containers, including no more than 5% PET from non‐food consumer applications. The flakes are heated in a continuous reactor under vacuum before being extruded. Having examined the challenge test provided, the Panel concluded that the continuous reactor (step 2, for which a challenge test was provided) is critical in determining the decontamination efficiency of the process. The operating parameters to control the performance of this step are temperature, pressure and residence time. It was demonstrated that this recycling process is able to ensure a level of migration of potential unknown contaminants into food below the conservatively modelled migration of 0.1 μg/kg food, derived from the exposure scenario for infants when such recycled PET is used at up to 100%. Therefore, the Panel concluded that the recycled PET obtained from this process is not considered to be 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, for long‐term storage at room temperature. 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 and Terms of Reference as provided by the requestor

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 Article 5 of Regulation (EC) No 282/20081 on recycled plastic materials intended to come into contact with foods and Articles 8 and 9 of Regulation (EC) No 1935/20042 on materials and articles intended to come into contact with food.

According to this procedure, the industry submits applications to the competent authorities of Member States, which transmit the applications to EFSA for evaluation.

In this case, EFSA received from the Bundesamt für Verbraucherschutz und Lebensmittelsicherheit, Germany, an application for evaluation of the recycling process Utsumi, European Union (EU) register No RECYC232. The request has been registered in EFSA’s register of received questions under the number EFSA‐Q‐2020‐00624. The dossier was submitted on behalf of Utsumi recycle Systems Inc, Japan.

According to Article 5 of Regulation (EC) No 282/2008 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 and deliver a scientific opinion on the recycling process examined.

According to Article 4 of Regulation (EC) No 282/2008, EFSA will evaluate whether it has been demonstrated in a challenge test, or by other appropriate scientific evidence, that the recycling process is able to reduce the contamination of the plastic input to a concentration that does not pose a risk to human health. The poly(ethylene terephthalate) (PET) materials and articles used as input of the process as well as the conditions of use of the recycled PET are part of this evaluation.

2. Data and methodologies

2.1. Data

The applicant has submitted a dossier following the ‘EFSA guidelines for the submission of an application for the safety evaluation of a recycling process to produce recycled plastics intended to be used for the manufacture of materials and articles in contact with food, prior to its authorisation’ (EFSA, 2008).

Additional information was provided by the applicant during the assessment process in response to requests from EFSA sent on 5 May 2021, 11 October 2021 and 22 December 2021 (see ‘Documentation provided to EFSA’).

The following information on the recycling process was provided by the applicant and used for the evaluation:

• General information:

  • –general description,
  • –existing authorisations.

• Specific information:

  • –recycling process,
  • –characterisation of the input,
  • –determination of the decontamination efficiency of the recycling process,
  • –characterisation of the recycled plastic,
  • –intended application in contact with food,
  • –compliance with the relevant provisions on food contact materials and articles,
  • –process analysis and evaluation,
  • –operating parameters.

2.2. Methodologies

The principles followed for the evaluation are described here. 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, 2008).

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 opinion developed by the EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (EFSA CEF Panel, 2011). The principle of the evaluation is to apply the decontamination efficiency of a recycling technology or 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. If the C_res is not higher than the C_mod, the recycled PET manufactured by such recycling process is not considered to be of safety concern for the defined conditions of use (EFSA CEF Panel, 2011).

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

3. Assessment

3.1. General information 3

According to the applicant, the recycling process Utsumi is intended to recycle food grade PET containers using the EREMA Basic technology. The recycled PET is intended to be used at up to 100% for the manufacture of materials and articles to be used in direct contact with all kinds of foodstuffs, such as bottles for mineral water, soft drink and beer as well as sheet/thermoforming applications for food containers, for long‐term storage at room temperature, with or without hotfill. The final articles are not intended to be used in microwave and conventional ovens.

3.2. Description of the process

3.2.1. General description ⁴

The recycling process Utsumi produces recycled PET pellets from PET containers from post‐consumer collection systems (kerbside and deposit systems).

The recycling process comprises the three steps below.

Input

• In step 1, the post‐consumer PET containers are processed into hot caustic washed and dried flakes. This step is performed by the applicant.

Decontamination and production of recycled PET material

• In step 2, the flakes are crystallised and decontaminated under high temperature and vacuum.

• In step 3, the decontaminated flakes are extruded to produce pellets.

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

Pellets, the final product of the process, are checked against technical requirements, such as intrinsic viscosity, colour and black spots.

3.2.2. Characterisation of the input ⁵

According to the applicant, the input material for the recycling process Utsumi consists of hot washed and dried flakes obtained from PET containers, e.g. bottles, previously used for food packaging, from post‐consumer collection systems (kerbside and deposit systems). A small fraction may originate from non‐food applications. According to the applicant, the proportion will be no more than 5%.

Technical specifications on the hot washed and dried flakes were provided, such as information on physical properties and on residual contents of moisture, poly(vinyl chloride) (PVC), glue, polyolefins, cellulose and metals (see Appendix A).

3.3. EREMA Basic technology

3.3.1. Description of the main steps ⁶

The general scheme of the EREMA Basic technology, as provided by the applicant, is reported in Figure 1. The steps are:

• Decontamination in a continuous reactor (step 2):

Figure 1.

General scheme of the technology (provided by the applicant)

The flakes are continuously fed into a reactor equipped with a rotating device, running under high temperature and vacuum for a pre‐defined minimum residence time.

• Extrusion of the decontaminated flakes (step 3):

The flakes, continuously introduced from the previous reactor, are molten in the extruder. ■■■■■

The process is run under defined operating parameters7 of temperature, pressure and residence time.

3.3.2. Decontamination efficiency of the recycling process ⁸

To demonstrate the decontamination efficiency of the recycling process Utsumi, a challenge test on step 2 was submitted to the EFSA.

PET flakes were contaminated with toluene, chlorobenzene, chloroform, methyl salicylate, phenylcyclohexane, benzophenone and methyl stearate, selected as surrogate contaminants in agreement with the EFSA guidelines (EFSA CEF Panel, 2011) and in accordance with the recommendations of the US Food and Drug Administration (FDA, 2006). The surrogates include different molecular masses and polarities to cover possible chemical classes of contaminants of concern and were demonstrated to be suitable to monitor the behaviour of PET during recycling (EFSA, 2008).

Solid surrogates (benzophenone and methyl stearate) and liquid surrogates (toluene, chlorobenzene, chloroform, methyl salicylate and phenyl cyclohexane) were added to 25 kg of conventionally recycled9 post‐consumer PET flakes. Sixteen such barrels were prepared and stored for 7 days at 50°C with periodical agitation. Afterwards, the contaminated flakes were rinsed with 10% ethanol. For each batch, the concentrations of the surrogates in the flakes were determined. The barrels were shipped to the EREMA facilities, where they were merged into two batches of 200 kg each.

Step 2 of the EREMA Basic technology was challenged at industrial scale. The contaminated flakes (200 kg) were fed into the decontamination reactor. Samples were taken at the inlet and outlet of the reactor, then analysed for their concentrations of the applied surrogates.

Instead of being operated continuously (as it would be in the industrial process), the challenge test was run in ■■■■■ mode. The Panel considered that the reactor ran at the same temperature and pressure as foreseen for the industrial process. In order to prove the representativeness of the residence time of the flakes in the challenge test, an additional challenge test running in continuous mode was provided. In this test, a mixture of green (contaminated) and clear (non‐contaminated) flakes was challenged. At different residence times, the ratio of green and clear flakes exiting the reactor was determined. Based on the results, the Panel concluded that the residence time in the challenge test ■■■■■ reactor corresponded to the minimum residence time in the industrial continuous reactor.

The decontamination efficiency of the process was calculated from the concentrations of the surrogates measured in the washed contaminated flakes introduced and those exiting the EREMA Basic reactor (step 2). The results are summarised in Table 1.

Table 1.

Efficiency of the decontamination of the continuous reactor (step 2) in the challenge test

Surrogates	Concentration of surrogates before step 2 (mg/kg PET)	Concentration of surrogates after step 2 (mg/kg PET)	Decontamination efficiency (%)
Toluene	391.3	0.9	99.8
Chlorobenzene	699.5	3.0	99.6
Chloroform	166.7	4.2	97.5
Methyl salicylate	982.6	6.4	99.3
Phenylcyclohexane	625.3	15.4	97.5
Benzophenone	927.1	22.4	97.6
Methyl stearate	1,599.1	15.8	99.0

PET: poly(ethylene terephthalate).

The decontamination efficiency ranged from 97.5% for chloroform and phenylcyclohexane up to 99.8% for toluene.

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.

Technical specifications, such as information on physical properties and residual contents of PVC, glue, polyolefins and metals, were provided for the input materials (i.e. hot caustic washed and dried flakes, step 1). These 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, mouth wash or kitchen hygiene agents. According to the applicant, the collection system and the process are managed in such a way that in the input stream this fraction will be no more than 5%, as recommended by the EFSA CEF Panel in its ‘Scientific opinion on the criteria to be used for safety evaluation of a mechanical recycling process to produce recycled PET intended to be used for manufacture of materials and articles in contact with food’ (EFSA CEF Panel, 2011).

The process is adequately described. The washing and drying of the flakes from the collected PET containers (step 1) is conducted in‐house and, according to the applicant, this step is under control. The EREMA Basic technology comprises the continuous decontamination reactor (step 2) and extrusion (step 3). The operating parameters of temperature, pressure and residence time have been provided to EFSA.

A challenge test to measure the decontamination efficiency was conducted at industrial plant scale on the process step 2 (decontamination reactor). The reactor was operated under pressure and temperature conditions as well as residence time equivalent to those of the commercial process. Since step 2 was conducted with only contaminated flakes, cross‐contamination could not occur. The Panel considered that this challenge test was performed correctly according to the recommendations of the EFSA guidelines (EFSA, 2008) and that step 2 was critical for the decontamination efficiency of the process. Consequently, temperature, pressure and residence time of step 2 of the process should be controlled to guarantee the performance of the decontamination (Appendix C).

The decontamination efficiencies obtained for each surrogate, ranging from 97.5% to 99.8%, have been used to calculate the residual concentrations of potential unknown contaminants in PET (C_res) according to the evaluation procedure described in the ‘Scientific opinion on the criteria to be used for safety evaluation of a mechanical recycling process to produce recycled PET’ (EFSA CEF Panel, 2011; Appendix B). By applying the decontamination percentages to the reference contamination level of 3 mg/kg PET, the C_res for the different surrogates was obtained (Table 2).

Table 2.

Decontamination efficiency from the challenge test, residual concentrations of the surrogates in the recycled PET (C_res) and calculated concentrations of the surrogates in PET (C_mod) corresponding to a modelled migration of 0.1 µg/kg food after 1 year at 25°C

Surrogates	Decontamination efficiency (%)	Cres for 100% rPET (mg/kg PET)	Cmod (mg/kg PET)
Toluene	99.8	0.01	0.09
Chlorobenzene	99.6	0.01	0.09
Chloroform	97.5	0.08	0.10
Methyl salicylate	99.3	0.02	0.13
Phenylcyclohexane	97.5	0.08	0.14
Benzophenone	97.6	0.07	0.16
Methyl stearate	99.0	0.03	0.32

PET: poly(ethylene terephthalate); rPET: recycled poly(ethylene terephthalate).

According to the evaluation principles (EFSA CEF Panel, 2011), 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 could result, after 1 year at 25°C, in a migration giving rise to a dietary exposure exceeding 0.0025 μg/kg bw per day. Because the recycled PET is intended for the manufacture of containers (also for drinking water), the exposure scenario for infants has been applied, (water could be used to prepare infant formula). A maximum dietary exposure of 0.0025 μg/kg bw per day corresponds to a maximum migration of 0.1 μg/kg of the contaminant into the infant’s food and has been used to calculate C_mod (EFSA CEF Panel, 2011). Cres reported in Table 2 is calculated for 100% recycled PET, for which the risk to human health is demonstrated to be negligible. 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 Utsumi using the EREMA Basic technology 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 0.1 μg/kg 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.

The Panel noted that the input of the process originates from Japan. In the absence of data on misuse contamination of this input, the Panel used the reference contamination of 3 mg/kg PET (EFSA CEF Panel, 2011) that was derived from experimental data from an EU survey. Accordingly, the recycling process under evaluation using the EREMA Basic technology is able to ensure that the level of unknown contaminants in recycled PET is below a calculated concentration (C_mod) corresponding to a modelled migration of 0.1 μg/kg food.

4. Conclusions

The Panel considered that the Utsumi recycling process using the EREMA Basic technology is adequately characterised and that the critical step to decontaminate the PET is identified. Having examined the challenge test provided, the Panel concluded that temperature, pressure and residence time in the continuous reactor of step 2 are critical for the decontamination efficiency.

The Panel concluded that the recycling process Utsumi is able to reduce foreseeable accidental 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 is from non‐food consumer applications;

3. the recycled PET is used at up to 100% for the manufacture of materials and articles for contact with all types of foodstuff, for long‐term storage at room temperature, including drinking water, with or without hotfill.

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 material 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 Regulation (EC) No 282/2008, Art. 4b. 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 ‘Utsumi’. September 2020. Submitted on behalf of Utsumi recycle Systems Inc, Japan.

Additional information, August 2021. Submitted on behalf of Utsumi recycle Systems Inc, Japan.

Additional information, October 2021. Submitted on behalf of Utsumi recycle Systems Inc, Japan.

Additional information, January 2022. Submitted on behalf of Utsumi recycle Systems Inc, Japan.

Abbreviations

bw

body weight

CEF Panel

Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids

CEP Panel

Panel on Food Contact Materials, Enzymes and Processing Aids

C_mod

modelled concentration in PET

C_res

residual concentration in PET

PET

poly(ethylene terephthalate)

PVC

poly(vinyl chloride)

rPET

recycled poly(ethylene terephthalate)

Appendix A – Technical specifications of the washed flakes as provided by the applicant10

Parameter	Value
Moisture max.	1.5%
Moisture variation	± 1.5%/h
Bulk density	300–450 kg/m3
Material temperature	10–35°C
PVC max.	25 mg/kg
Glue max.	1,000 mg/kg
Polyolefins max.	50 mg/kg
Cellulose (paper, wood)	100 mg/kg
Metals max.	100 mg/kg
PET dust max.	0.5%

PVC: poly(vinyl chloride); PET: poly(ethylene terephthalate).

Appendix B – Relationship between the key parameters for the evaluation scheme (EFSA CEF Panel, 2011)

*Default scenario (infant). For adults and toddlers, the migration criterion will be 0.75 and 0.15 µg/kg food, respectively. The figures are derived from the application of the human exposure threshold value of 0.0025 μg/kg bw per day applying a factor of 5 related to the overestimation of modelling.

Appendix C – Table of operational parameters (Confidential Information)11

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Suggested citation: EFSA CEP Panel (EFSA Panel on Food Contact Materials, Enzymes and Processing Aids) , Lambré C, Barat Baviera JM, Bolognesi C, Chesson A, Cocconcelli PS, Crebelli R, Gott DM, Grob K, Mengelers M, Mortensen A, Rivière G, Steffensen I‐L, Tlustos C, Van Loveren H, Vernis L, Zorn H, Dudler V, Milana MR, Papaspyrides C, Tavares Poças MF, Lioupis A and Lampi E, 2022. Scientific opinion on the safety assessment of the process Utsumi, based on the EREMA Basic technology, used to recycle post‐consumer PET into food contact materials. EFSA Journal 2022;20(5):7278, 13 pp. 10.2903/j.efsa.2022.7278