ESC 3.1: How to Measure and Understand Material Inflow

• Why material inflow matters
• What ESC3.1 requires 
• How to measure and document material inflow 
• In Summary
• Further Information

Introduction

When your company uses physical products or packaging, knowing what materials come in is the first step toward becoming more circular. ESC 3.1 in the Environmental Stewardship & Circularity topic asks companies to track the materials they use so they can reduce virgin, non-renewable materials and, therefore, reduce the pressure on natural resources.

This article explains why measuring your material inflow matters, outlines the requirements under ESC3.1, and specifies how to measure it.

Why material inflow matters

“Material inflow” means the raw materials, components, and packaging the company procures to produce its products or services. They lie at the core of every economic activity, yet are too often overlooked.

Understanding your material inflow represents a cornerstone to move forward in building an inclusive, equitable and sustainable economy. They are key in comprehending one’s dependence on natural resources and the associated impacts on their sustainability. As such, using renewable materials from sustainable sources helps reduce the pressure and impacts on natural resources your activity may bring.

What ESC3.1 requires 

ESC 3.1 requires large and bigger companies (Large, X Large, XX Large) in all sectors except Service with Minor Footprint to provide an overview of material inflow indicators for both products and packaging, covering:

• Total weight (in tonnes) of input materials used for products and for packaging.

• Weight and percentage of renewable input materials from third‑party verified, sustainable sources (products and packaging).

• Weight and percentage of reused or recycled (non‑virgin) materials used in products and packaging.

The requirement applies for the fiscal year before Year 0 and for each subsequent year. It covers products the company produces or has produced on its behalf. Resold products can be exempt in wholesale/retail, and service companies only need to comply if they sell physical products and control their production. 

Please note that under B Lab’s Risk Profile Tool, a question on the use of single-use plastic products and packaging from virgin non-renewable materials (FR3.1.e) may trigger requirement ESC3.1 for other sizes and sectors.

B Lab’s standards require the following materials to be included in the overview:

• Raw materials — natural resources converted into products or services, such as ores, minerals, and wood. Raw materials exclude water, which is captured under ESC1.3.

• Associated process materials — materials that are used in the manufacturing process but not part of the final product, such as lubricants and coolants.

• Semi-manufactured goods or parts — all forms of materials and components other than raw materials that are part of the final product.

• Packaging materials — including paper, cardboard, and plastics. The intent is that the company focuses on its primary and secondary packaging, however, this is not mandated by the sub-requirement, there is flexibility. Also, if legislation prevents the company from implementing circular design principles for its primary and secondary packaging, it can decide to focus on tertiary packaging instead.

How to measure and document material inflow 

1. Confirm applicability in the B Impact : complete B Lab’s Risk Profile and confirm whether ESC3.1 appears in the list of requirements for Year 0 ;

2. Define your product and packaging scope : 

   • List all products you produce or have produced on your behalf (excluding purely resold items where applicable),

   • For each product line, list associated packaging (which may be primary, secondary, and if relevant tertiary) 

3. Set up your material inflow tracking: work with procurement, operations, or finance to pull annual data (in tonnes) from internal spreadsheets, procurement platforms, or ERP systems. For each product and packaging category, record:

   • Total input material by weight,

   • Weight and % of renewable materials from third‑party verified sustainable sources,

   • Weight and % of reused or recycled (non‑virgin) materials ;

4. Store and update your annual overview : Maintain a consolidated file that clearly separates products and packaging. Update it at least once per fiscal year so it always covers the previous year and any subsequent years required for your audit cycle.

5. Upload evidence in B Impact: Under ESC 3.1 in B Impact, upload your latest material inflow overview and any supporting documentation (e.g., certification reports, supplier certificates).

In Summary

ESC 3.1 is about knowing your material baseline: how much material you use, and how much of it is renewable, recycled, or reused, across products and packaging. This data underpins later requirements to reduce virgin non‑renewable materials and increase circularity.

Further Information

• Read the Environmental Stewardship & Circularity Impact Topic for the full compliance criteria and definitions

• Review the ESC Impact Topic Summary for a concise overview of requirements

• Go through the ESC Impact Topic Documentation and Evidence guide

• For broader context, consult the ESC Impact Topic Companion Guide