Overview
The purpose of this article is to provide companies with a brief overview of the Food and Drug Administration's (FDA) recommendations regarding the use of recycled plastics in food packaging applications in the US. We hope that you will find this background helpful, and we welcome the opportunity to assist you with any specific questions regarding the use of recycled materials here or around the globe, moving forward.
I. Background
The US Food and Drug Administration (FDA) has not yet promulgated any specific regulatory requirements pertaining to the use of recycled plastics in food packaging materials and articles. Instead, and consistent with FDA's Good Manufacturing Practice (GMP) and suitable purity requirements, it is the responsibility of the manufacturer, re-processor or converter to ensure that a finished food-contact material or article containing recycled material is suitable for use in food-contact applications.1 That is, when used as intended, the finished food-contact material or article containing recycled material should not adversely impact the health or safety of food, nor should it impart any organoleptic qualities that would render the food unfit for consumption (i.e., by creating an off-taste or odor). For certain recycled materials, the recycler or user of recycled materials should also consider, evaluate, and reduce, where necessary, the presence of heavy metals that may be present in the source material and available to migrate at low levels to food.
FDA recognizes that a variety of materials can be recycled based on existing technologies, but that the specific chemistry and safety considerations for each type of material necessarily depend on the composition and regulatory status of the recycled material input, the composition of the blended virgin material (if applicable), and the end-use of the finished resin. Polyethylene terephthalate (PET) is a widely-recognized input for recycled plastics, but as recycling technologies continue to advance, new and innovative processes have allowed for the increased recycling rate of polyolefins (such as high-density polyethylene (HDPE), low-density polyethylene (LDPE) and polypropylene (PP), polystyrene, polycarbonate, and other novel materials.
As discussed more fully below, and in addition to traditional recycling technologies that have been in place for decades, the use of specific recycling methodologies – including strict limitations on source control and sorting measures – have given rise to additional opportunities to use recycled materials in food-contact applications.
II. Definition of Recycling Processes
There are currently three broadly recognized types of recycling processes, as originally defined by the US Environmental Protection Agency (EPA) in 1991:
- Primary Recycling – The use of pre-consumer scrap and regrind that is re-processed into a new material or article. Typically, this scrap and regrind never leaves the production plant before it is recycled, and therefore, the material is never exposed to use conditions that could adversely impact the suitability of the material (i.e., it is never placed in contact with food, nor is it used under elevated temperature conditions). Provided that the pre-consumer scrap and regrind otherwise complies with applicable FDA food additive regulations for the intended use, and further provided that the regrind is not otherwise contaminated in-plant, the finished material or article manufactured using primary-recycled materials should continue to comply with applicable FDA requirements. This recycling process is also referred to as "first degree" recycling.
- Secondary Recycling – The physical reprocessing of post-consumer packaging materials. Secondary recycling usually involves some combination of washing, drying and/or extrusion of post-consumer resin to clean-up and remove unwanted residues, impurities or byproducts that may have contacted the plastic during its original lifetime. Depending on the intended use conditions of the source material, additional steps may be required to ensure that the finished resin is suitably pure for use in recycling applications. Post-consumer packaging materials that are used in secondary recycling applications should be made from: (1) materials that were suitable for use in food-contact applications for the original application; and (2) were not subjected to industrial use (i.e., materials not intended for consumer or household use – even if the material otherwise complies with FDA requirements for food-contact applications). For this reason, FDA generally expects that secondary recycling re-processors shall maintain strict source control measures to ensure that the incoming resin is suitable for recycling. This recycling process is also referred to as "second degree" recycling.
- Tertiary Recycling – The chemical reprocessing of post-consumer packaging materials. Tertiary recycling usually involves the use of one or more chemical processes (i.e., glycolysis, methanolysis, distillation or crystallization), in addition to any of the optional secondary recycling processes described above, to reduce the finished polymer back into its constituent monomers or oligomers that, in turn, can be purified and then re-polymerized into a finished resin. For certain materials – such as PET – FDA has received sufficient data from industry over the years to demonstrate that tertiary recycling processes sufficiently reduce or eliminate impurities that may have been present in the original resin at levels that could impact the suitable status of the repolymerized resin, such that additional testing may not be necessary. This process is also referred to as "third degree" recycling.
III. FDA's No Objection Letter (NOL) Process
As discussed above, FDA does not require that manufacturers of finished food-contact materials and articles containing recycled material obtain approval from the Agency before introducing recycled materials into the market, nor does the Agency provide any type of explicit sanction. Instead, and in response to industry’s desire to demonstrate to their suppliers and customers that their process has been reviewed by FDA, the Agency established a No Objection Letter (NOL) process by which companies can submit a description of their recycling process – including any relevant testing procedures and results evaluating the same – and obtain a letter from FDA confirming that the Agency has "no questions" regarding the company’s recycling process. More specifically, FDA states that an NOL is not a sanction or approval, but instead, a recognition that FDA has reviewed the recycling process and determined that it currently has "no questions" regarding the suitability of the recycling process to sufficiently remove unwanted contaminants. FDA maintains a list of No Objection Letters that it has provided to industry since the program first began in 1990 – nearly 300 in total as of the date of this writing. As noted above, the majority of NOL letters cover PET recycling processes; however, a number of more recent NOL submissions cover olefin homopolymers and copolymers, polystyrene, and polycarbonates used in recycling processes.
Not all recycling processes are equally effective in reducing contaminants under all intended use conditions, and for this reason, FDA's NOL letters sometimes contain limitations with regard to Food Type or Condition of Use.2 These limitations often address the fact that recycling processes can be very effective in reducing certain types of impurities and byproducts, but less effective in reducing others (described more fully below). For this reason, the application of one or more Food Type or Condition of Use limitations are often effective in ensuring that substances that are not as effectively removed during the recycling process cannot migrate at unacceptable levels to food, under the intended use conditions of the finished resin.
IV. Methods for Demonstrating Suitability of the Recycling Process
FDA generally takes the position that a contaminant has been sufficiently controlled (i.e., reduced or eliminated) through the application of a recycling process when the subject contaminant will not be present in the diet at a level in excess of 0.5 part per billion (ppb), when evaluating the intended use of the finished recycled material or article. This dietary concentration (DC) is equivalent to an Estimated Daily Intake (EDI) value of 1.5 micrograms per person per day (1.5 µg/p/day), and is consistent with FDA's Threshold of Regulation for substances used in food-contact articles, described at 21 C.F.R. § 170.39. That is, where substances are not otherwise expected to be carcinogenic, mutagenic, or reproductive toxicants (CMRs), the presence of a substance in the diet at 0.5 ppb or below would be expected to present a negligible toxicological risk.
While FDA has not yet promulgated any regulatory requirements pertaining to the use of recycled materials in food-contact applications, the Agency has drafted a guidance document, entitled, Guidance for Industry: Use of Recycled Plastics in Food Packaging (Chemistry Considerations) (July 2021) that is instructive in methods that can be used to ensure that the finished, recycled material is suitably pure for the intended use.3 Although this Guidance Document is considered non-binding, the principles set forth therein are widely accepted throughout industry. Of course, companies are free to develop alternative methodologies and processes for ensuring and demonstrating that a recycling process is sufficient to reduce contaminants below the 0.5 ppb threshold described above.
The Guidance Document contains detailed recommendations for evaluating the efficacy of a secondary or tertiary recycling process through the use of surrogate contaminant testing (commonly referred to as "challenge testing"). Under the challenge testing process, FDA recommends that a company subject virgin polymer to surrogate contaminants, then process the polymer through the recycling method. Following completion, the challenged polymer is analyzed to measure the efficacy of the recycling process (reduction of the surrogate contaminants relative to the original challenge amounts). FDA recommends that challenge testing include the use of at least four categories of surrogates, designed to mimic the various types of potential consumer misuse of materials destined for recycling: (1) volatile polar; (2) volatile non-polar; (3) non-volatile polar; and (4) non-volatile non-polar.4
Under the proposed challenge test protocol, the surrogates are either used and evaluated independently, or blended into a cocktail (provided that the surrogates are not otherwise expected to react with each other), and the polymer is submerged into the mixture for appropriate time periods and at specified temperatures with periodic agitation to reflect potential long-term storage of a misused food-contact material or article at room temperature (e.g., a household consumer that uses an empty food-contact container to store used motor oil prior to disposal). Containers can be challenged in the surrogate mixture at "neat" or "at use" concentrations (depending on the volume of material tested and the analytical capabilities of the testing laboratory).
Following the challenge phase, containers are analyzed at various points during the recycling process (i.e., in the case of the secondary recycling process, following the washing, drying and extrusion/heating phases) to measure the efficacy of each step, or once at the end of the recycling process to demonstrate the efficacy of the overall recycling process. Provided that the recycling process is sufficient to reduce the challenged contaminants to levels at or below 0.5 ppb, and subject to the other GMP and suitable purity considerations described above, the finished polymer produced using the recycling process may be considered acceptable for use in food-contact applications.
V. Additional Considerations
Where a recycling process is sufficient at reducing certain contaminants – but not others – below the 0.5 ppb threshold, companies may rely on various alternatives to selectively introduce the use of recycled materials into food-contact materials or articles, such that the overall level of the contaminant would not be present in the diet at levels in excess of 0.5 ppb.
For example, alternatives include: (1) blending of recycled and virgin material, to effectively dilute the presence of any remaining contaminants below 0.5 ppb; (2) limiting the types of food that the finished material may contact (particularly if the remaining contaminant(s) have a greater propensity to migrate to certain food types, as compared to others); and/or (3) limiting the temperature Conditions of Use that the finished material may contact (specifically, where it can be demonstrated that the contaminant would more readily migrate to food under elevated contact temperatures, but would not be expected to migrate in significant quantities at lower contact temperatures). Blending and restrictions on Food Types and Conditions of Use are often particularly helpful in the case of olefin copolymer recycling processes, where the composition of the post-consumer resin (i.e., the recycling input) would be expected to vary significantly from batch to batch, depending on the additive package used to stabilize the original resin.
Companies may also choose to implement strict source control measures designed to ensure that incoming "post-consumer" material is less likely to contain contaminants in significant quantities. It remains the responsibility of the NOL holder to ensure that the actual recycling process complies with the description and applicable use limitations in the NOL request, and for this reason, NOLs that are based on strict source control procedures must be closely adhered to in order to ensure that the incoming material is suitably pure.
Finally, companies potentially can make use of a functional barrier between the recycled resin and food to establish a suitable status for the recycled resin. Briefly, when a substance is separated from contact with food by the presence of a "functional barrier" between the substance and food that prevents the substance from migrating to food, the substance does not meet the "food additive" definition, as that term is defined by the Federal Food, Drug, and Cosmetic Act, and premarket approval by FDA is not required. This is because the "functional barrier" prevents the substance from being "reasonably expected to become a component of food" when used as intended.5 Note, however, that the mere presence of a layer between the recycled substance and food does not mean that the layer constitutes a "functional barrier." The intervening layer must prevent the migration of the substance that may be present in the recycled material to the food, and this determination must necessarily be made on a case-by-case basis.
VI. Concluding Thoughts
Recycling technologies and processes are rapidly evolving with new innovations in the marketplace, as are the analytical capabilities used to measure the presence or absence of impurities, byproducts, and contaminants in a recycled resin. While there is no strict regulatory requirement (or indeed, any mechanism) to obtain FDA "approval" for a recycling process, clear guidelines from the Agency regarding methods and processes to demonstrate suitable purity and compliance with GMP dictate that companies have an ongoing responsibility to continuously and adequately evaluate the use of recycled materials for their specific intended use, on a case-by-case basis.
Endnotes
1 See 21 C.F.R. § 174.5 ("General provisions applicable to indirect food additives").
2 See https://www.fda.gov/food/packaging-food-contact-substances-fcs/food-types-conditions-use-food-contact-substances.
3 See https://www.fda.gov/regulatory-information/search-fda-guidance-documents/guidance-industry-use-recycled-plastics-food-packaging-chemistry-considerations.
4 FDA previously recommended a fifth surrogate – a heavy metal salt – in the case of PET, but has concluded based on industry data and submissions that the propensity of heavy metal salts to sorb into the PET polymer matrix is low, and any heavy metal salts that do sorb generally tend to remain on the surface (and are therefore effectively removed through simple washing steps). The use of a heavy metal salt is, however, still recommended for non-PET recycling applications.
5 See Natick Paperboard v. Weinberger, 525 F.2d 1103 (1st Cir. 1975), cert. denied, 429 US 819 (1976).
