How scores are calculated

The Responsible Sourcing Scheme (RSS) helps growing media manufacturers, suppliers and users understand the environmental and social impacts associated with growing media ingredients. Each major ingredient that makes up more than 5% of a mix is assessed against seven responsible sourcing criteria.

These twelve snapshots provide a straightforward introduction to the areas assessed by the RSS, including:

• Greenhouse Gas Emissions – measuring the climate impact associated with extraction, transport and production. Emissions are expressed as kg CO₂e/m³, with additional peat-specific emissions included where relevant.

• Water Use – examining the source and quantity of water used during extraction and production.

• Social Compliance – considering fair labour, safe working conditions and responsible practices throughout the supply chain.

• Habitat & Biodiversity – examining the origin of each ingredient and its potential effects on habitats, ecosystems and wildlife.

• Pollution, Renewability and Resource Use Efficiency – assessing local pollution risks, how quickly resources are replenished and how effectively materials and by-products are used.

Each snapshot explains what is covered, the evidence that may be required and practical ways to improve performance. They provide a helpful overview and should be used alongside the current Version 11 Guidance Notes for the complete assessment requirements.