bluesign on Safe Chemical Recycling for Polyester

As global fashion supply chains face increasing regulatory pressures, material circularity goals, and chemical safety requirements, textile-to-textile polyester recycling has become a vital solution. bluesign®, a recognized leader in sustainable chemical management, leverages its expertise in both mechanical and chemical recycling through the bluesign Academy, in-house research, and collaborations with system partners.

This latest briefing combines findings from bluesign Academy’s research, focusing on the complexities of chemical recycling processes, purification requirements, and regulatory considerations. The insights are tailored to support reporting on climate-focused innovation, textile regulation, and material science within fashion.

bluesign emphasizes that recycling is not sustainable unless the underlying chemistry is safe. Effective chemical recycling demands strict controls over input materials, solvents, and emissions. With its expertise, bluesign ensures polyester recycling advances circularity without compromising safety.

How Polyester Recycling Works

The process follows these key stages:
Collection → Cleaning → Shredding → Depolymerization → Purification → Repolymerization → Pelletization

Depolymerization: PET is broken down into monomers such as BHET, TPA, or DMT through methods like glycolysis, hydrolysis, or methanolysis.
Purification: Solvent extraction, distillation, crystallization, or filtration remove harmful residues, dyes, coatings, blended fibers, and additives.
Output: High-grade recycled polyester with “virgin-like” quality, suitable for performance textiles and compliant with evolving chemical safety regulations.

Mechanical vs. Chemical Recycling

Mechanical recycling involves minimal processing without altering the polyester polymer but does not remove contaminants from original feedstocks such as dyes, coatings, or restricted substances (PFAS, Bisphenols, heavy metals, PVC). It also leads to microplastic shedding during reprocessing.

By contrast, chemical recycling breaks polyester into monomers using heat, solvents, and catalysts. Processes like glycolysis, methanolysis, hydrolysis, or enzymatic depolymerization involve chemical inputs and potential emissions, requiring strict management.

Common Inputs by Process

Glycolysis: Ethylene glycol, catalysts (e.g. zinc acetate)
Methanolysis: Methanol, pressure, heat, sodium hydroxide
Hydrolysis: Sulfuric acid, caustic soda, water/steam
Enzymatic: Enzymes such as cutinases/esterases, buffers

Potentially Released or Risky Chemicals

VOCs and solvents like methanol, toluene, DMF, DMSO
Catalyst residues from depolymerization
Dyes, coatings, and blended fiber residues
Restricted substances such as heavy metals, PFAS, phthalates, flame retardants

Without purification and emission controls, these substances can harm workers, facilities, local environments, and even consumers.

bluesign’s Role in Chemical Management

bluesign’s chemical management approach for recycled polyester includes:

Evaluating chemical inputs and associated risks
Verifying purification systems to ensure contaminants are fully removed
Monitoring emission control measures (e.g. condensers, scrubbers, activated carbon) and wastewater treatment
Confirming compliance of recycled PET with bluesign’s strict chemical limits (BSBL, BSSL), aligned with regulations like REACH, ZDHC MRSL, and AFIRM RSL

Regulatory Drivers Accelerating Polyester Recycling

EU ESPR (Ecodesign for Sustainable Products Regulation):
Introduces Digital Product Passport, prioritizes textiles (2025–2027), mandates recyclability and recycled content.
EU Waste Framework Directive (2025 revision):
Requires textile waste collection, Extended Producer Responsibility (EPR), and recycling targets.
California SB 707 (Textile Recovery Law):
First U.S. mandatory EPR scheme requiring closed-loop recycling, full brand compliance by 2030.
REACH proposals on dyes and PFAS:
Plans to restrict chemicals common in textiles, reinforcing chemical recycling as essential to compliance.

Why bluesign is a Media Resource

Deep expertise in chemical inputs, safety systems, and recycling performance
Leadership at the intersection of sustainability, compliance, and material science
A global network of 970+ supply chain partners
Access to scientists, chemists, and engineers for expert commentary and insights