May 05, 2026

What is GRS Certification? How to Verify Recycled Materials Are Genuine

 

Introduction

What is GRS Certification? The Global Recycled Standard (GRS) is a holistic international protocol that verifies not only recycled content (minimum 20%) but also strict social, environmental, and chemical practices across the entire supply chain. For brands requiring the GRS hangtag, a minimum of 50% recycled content is mandatory. A key mechanism is the Transaction Certificate (TC), which ensures 100% traceability from source to finished fabric. Honmyue Enterprise, Taiwan's largest user of recycled yarn, has been GRS-certified since 2015. With 5 certified production bases across Taiwan, and China, product categories include dyed fabrics, greige fabrics, and greige yarns—36 product combinations, with materials covering recycled polyester (Post-Consumer/Pre-Consumer) and recycled nylon (Post-Consumer/Pre-Consumer).

The 5 Core Standards of GRS: Beyond Material Content Verification

Many believe GRS only tracks "recycled percentage," but it's actually a comprehensive system covering social responsibility, environmental management, and chemical safety, which is why it is trusted by global leaders like Nike, Adidas, and Patagonia

📊 GRS Certification Market Insights (2024-2025)

Global Certified Suppliers
12,400+
18% YoY Growth
Asia Market Share
68%
Taiwan: 14% of Asia
Annual TC Issued
8.5M+
Global Total
Brand Adoption
89%
Fortune 500 Textile Brands

Standard 1: Recycled Content Verification (20-100%)

Content LevelGRS RequirementBrand Practice
Entry Level20-49%Rarely used
Standard Level50-99%Most brand requirement
Premium Level100%High-end brand specification

Standard 2: Chain of Custody

This is GRS's most critical and stringent requirement. Every link in the supply chain must:

  1. Obtain GRS certification: From recyclers, fiber mills, textile mills to dyeing & finishing plants
  2. Issue Transaction Certificates: TC required for each transaction, recording material flow
  3. Separate storage: Recycled and virgin materials must be stored separately to avoid mixing
  4. Mass balance: Input recycled material weight must reasonably correspond to output

Standard 3: Chemical Management

GRS restricted substance list includes:

  • Azo dyes: 24 types that may release carcinogenic aromatic amines
  • Heavy metals: Lead, cadmium, mercury, hexavalent chromium (limit < 1 ppm)
  • Halogenated flame retardants: TBBPA, HBCD, etc.
  • Specific solvents: NMP, DMF, and other high-risk solvents

Verification: Wastewater COD < 150 mg/L, pH 6-9, heavy metal testing

Standards 4 & 5: Social Responsibility and Environmental Management

CategoryCore RequirementsAudit Method
Social ResponsibilityILO core conventions: No child labor, no forced labor, reasonable hours & wagesWorker interviews, payroll verification
Environmental ManagementWastewater treatment, energy records, solid waste classificationEnvironmental monitoring data, facility inspection

How Transaction Certificates (TC) Work: The DNA of Traceability

If GRS certification is an "ID card," then the Transaction Certificate is the "DNA record of every transaction." Let's break down how it works.   

What Key Information Does a TC Contain?

FieldExample ContentTraceability Function
TC NumberGRS-TC-2026-HM-001234Global unique identifier
Seller GRS Certificate No.IDF-24-635174 (IDFL issued)Verify supplier certification validity
Product DescriptionDyed 100% Recycled Polyester Fabric, 300DClear product specification
Recycled Material TypeRecycled Post-Consumer Polyester (Post-Consumer)Distinguish recycling source level
Recycled Content100%Brand ESG calculation basis
Transaction Volume5,000 kg / 12,000 yardsMass balance verification
Upstream TC NumberGRS-TC-2026-YS-000987 (yarn mill)Upstream supply chain tracing

How to Verify TC Authenticity?

  1. Check TC number format: Should include year, certification body code, serial number
  2. Verify GRS certificate validity: Seller's certificate must be valid (typically 1 year)
  3. Upstream TC linkage: Confirm upstream TC number is verifiable
  4. Quantity reasonableness: 5,000kg finished product should correspond to ~5,250kg raw material (accounting for loss)
  5. Online verification: Certificate numbers can be verified on Textile Exchange website

Honmyue's GRS Portfolio: Certified Since 2015

🏭 Five GRS-Certified Production Facilities

✓ HONMYUE ENTERPRISE CO., LTD. (main)  ✓ HONMYUE ENTERPRISE CO., LTD. - CHUANHSIN FACTORY  ✓ UTEX INNOVATION CO., LTD. ✓ HONMYUE TEXTILE (ZHEJIANG) CO., LTD. ✓ JIUJIANG DEYU CO., LTD.

📂 Certificate Download

Download GRS Certificate (PDF)

📅 Certified Product Range

Product CategoryCoverageRecycled Material Sources
Dyed FabricsDyed Fabrics - Woven Fabrics
(PC0025 - PD0059)
• Recycled Post-Consumer Polyamide (nylon)
• Recycled Post-Consumer Polyester
• Recycled Pre-Consumer Polyamide (nylon)
Greige FabricsGreige Fabrics - Woven Fabrics
(PC0026 - PD0059)
• Recycled Post-Consumer Polyamide (nylon)
• Recycled Post-Consumer Polyester
• Recycled Pre-Consumer Polyamide (nylon)
• Recycled Pre-Consumer Polyester
Greige YarnsGreige Yarns - Filament
(PC0030 - PD0069)
• Recycled Post-Consumer Polyester
• Recycled Pre-Consumer Polyamide (nylon)

4 Critical Checkpoints for Choosing a GRS Supplier

There are many GRS suppliers in the market, but "having certification" doesn't equal "being a good supplier." Based on our experience helping brand customers, here are the most critical checkpoints.

Checkpoint 1: Certification History and Stability

Certification YearsRisk AssessmentRecommendation
< 2 yearsSystem not yet mature, limited TC issuance experienceCareful evaluation
2-5 yearsStable system, but may lack complex order experienceSmall batch testing
5+ yearsExperienced, reliable TC traceabilityPreferred choice

Checkpoint 2: TC Issuance Capability

✅ Request from Supplier:

  • Past 12 months TC samples: At least 3 TCs from different customers (sensitive info redacted)
  • Check TC content: Are upstream TC numbers complete? Are quantities reasonable?
  • Online verification: Query their GRS certificate number on Textile Exchange website
  • Question test: Ask "If I need to trace back to the recycling source, can you provide the complete TC chain?"

Checkpoint 3: Product Range Completeness

Many suppliers only have single-process certification (e.g., weaving only, no dyeing & finishing), leading to:

  • Need to transfer orders to other GRS dyeing plants, increasing coordination costs
  • TC chain becomes longer, traceability complexity increases
  • Extended lead times, quality control difficulties

🏆 Honmyue Advantage: Five facilities cover "weaving → dyeing & finishing" complete process, single supplier can issue complete TC chain.

Checkpoint 4: Upstream Supply Chain Stability

Key Checks:

  • How many GRS-certified upstream suppliers does the supplier have? (At least 2-3)
  • Are there backup suppliers? How long to switch?
  • When do upstream suppliers' certifications expire? (Avoid concentration at same time)