Lesson 4 — Common Sustainability Metrics

Introduction

Welcome back.
In the previous lesson, you learned how complex the textile supply chain is — and how impacts appear at every stage.

Now the question becomes: How do we actually measure these impacts?

In this lesson, we’ll explore the four most common sustainability metrics used by brands, auditors, and regulators:

1. CO₂ footprint

2. Water use & wastewater

3. Chemical use & hazardous substances

4. Waste & recycling rates

These metrics form the foundation of every sustainability strategy — from internal improvements to external communication and regulatory compliance.

1. CO₂ Footprint – Understanding Scope 1, 2, and 3

The textile industry generates around 10% of global greenhouse gas emissions.

To measure emissions, we use three scopes:

Scope 1

Direct emissions from a company’s own operations
(e.g., factory boilers, vehicles).

Scope 2

Indirect emissions from purchased energy
(e.g., electricity used in factories or offices).

Scope 3

All other indirect emissions across the entire value chain
(e.g., fiber production, spinning, transport, customer use).

Example:
A denim brand discovers that 80% of its total carbon footprint comes from cotton farming (Scope 3), not from its own factory.

Why this matters:
If a brand focuses only on Scope 1 and 2, it ignores the biggest sources of emissions — which usually happen far earlier in the supply chain.

2. Water Use and Wastewater

Water is one of the most critical sustainability issues in textiles.

Where water is used:

• Fiber cultivation (cotton, flax, hemp)

• Dyeing and finishing

• Washing and processing

Example:
Producing one pair of jeans can require 7,500–10,000 liters of water.

Wastewater concerns:

• Dye effluents contain salts, heavy metals, and toxic chemicals

• 20% of global industrial wastewater comes from textile dyeing and finishing

Best practice example:
Arvind Mills (India) recycles 90% of its wastewater, reducing environmental pressure on local communities.

3. Chemical Use and Hazardous Substances

Textile production relies on thousands of chemicals:

• Dyes

• Finishes

• Softening agents

• Flame retardants

• Water repellents

• Anti-microbial treatments

Risks:

• Worker exposure

• Consumer safety issues (skin irritation, allergies)

• Environmental contamination

Example:
OEKO-TEX® Standard 100 tests finished garments for harmful substances to ensure they are safe for human contact.

Hypothetical case:
A children’s clothing line fails chemical tests due to high formaldehyde levels, leading to recalls and brand damage.

4. Waste and Recycling Rates

Waste occurs long before a product reaches the customer — and long after it leaves the store.

Types of waste:

• Pre-consumer: cutting scraps, defects, leftover rolls

• Post-consumer: clothes thrown away by customers

Current reality:

• 87% of textiles end up in landfill or incineration

• Only 1% is recycled into new textiles

Best practice example:
A sportswear brand collects worn-out garments in-store and turns them into insulation material — giving textiles a second life.

5. Why Measuring Matters

Sustainability metrics allow brands to:

Track performance internally

(e.g., reducing emissions or water use year over year).

Report transparently to customers, investors, and stakeholders

Credible metrics reduce greenwashing risks.

Comply with regulations

Such as the EU Corporate Sustainability Reporting Directive (CSRD) and upcoming textile-specific legislation.

Example:
A brand reports reducing its CO₂ emissions by 25% over three years, helping secure investment from a sustainability-focused fund.

6. Practical Exercise

Choose one of your own products (or a client’s) and:

1. Identify the most carbon-intensive stage

2. Identify where the most water is used

3. Note any chemicals used that may pose risks

4. Suggest one way to improve recyclability

You’ll use these findings in the next lesson when we connect metrics to standards and certifications.

Closing – Transition to Lesson 5

Now that you understand how impacts are measured, you’re ready to explore how sustainability standards work.

In the next lesson, we dive into the ecosystem of global standards — from voluntary initiatives like Textile Exchange and Fashion Revolution to mandatory regulations — and how they form the basis for certifications like GOTS, GRS, RWS, and OEKO-TEX®.