How Greener Closet Scores Clothing
The Greener Closet score is a 0–100 rating of a clothing product's potential health and environmental concerns, calculated from its stated material composition. Each product starts at 100 points; penalties are applied per material, weighted by its share of the garment, across six research-based factors, with a small adjustment for certification disclosure.
Last updated: August 2026. A higher score indicates fewer potential concerns — every score represents tradeoffs, not judgments.
Analyze a ProductThe Six Factors
Every product is evaluated against the same six measurable factors. Factor weights reflect relative health impact based on current research and are updated as new evidence emerges.
Synthetic fabrics like polyester and nylon shed tiny plastic particles during wear and washing. These particles enter waterways and, potentially, your body.
Per- and polyfluoroalkyl substances are used in water-resistant and stain-resistant treatments. They're persistent in the environment and have been linked to health concerns.
How long a material takes to decompose. Synthetic materials can persist for hundreds of years, while natural fibers break down much faster.
The energy required to produce each material varies significantly. Polyester from virgin petroleum requires more energy than organic cotton or recycled fibers.
Certain azo dyes can release aromatic amines, some of which are classified as carcinogenic. We flag materials commonly associated with these dye processes.
How much a fabric sheds fibers during use. This affects both indoor air quality and water systems when garments are washed.
The Scoring Process
- Extract the composition. From a submitted product URL, we identify the stated fabric composition, certifications, and manufacturing details on the product page.
- Match against our materials database. Each material is matched to a database of textile materials and their known properties, compiled from peer-reviewed research on textile health impacts, environmental assessments, and industry standards bodies.
- Apply proportional penalties. Starting from 100 points, penalties are calculated separately for each material across the six factors, weighted by that material's proportion of the garment, then combined. A small final adjustment reflects whether certification information is present in the product data.
We don't publish the exact factor weightings, raw materials-database penalty inputs, and formulas: they're revised continuously as new research is incorporated — a fixed published table would go stale almost immediately — and they're the core of the analysis engine we build. What we publish is everything needed to interpret a score. When studies conflict, we err on the side of caution; when we encounter a material we don't recognize, we flag it for review rather than guessing.
What the Score Can't Tell You
We can only analyze what retailers disclose. If a product page says "100% cotton," we analyze it as cotton — we can't verify claims, detect unlisted treatments, or identify supply chain issues.
We don't currently test products in a lab. Our analysis is based on stated materials and the known properties of those materials, documented in the research our database is built on.
Scores estimate potential concerns. They're not medical advice: individual sensitivity varies, and exposure context matters. Treat a score as a starting point for understanding materials, not a comprehensive safety assessment.
Methodology questions
How is the final score calculated?
Each product starts at 100 points. We apply penalties based on the materials present, weighted by their proportion in the garment and the severity of each health factor. A shirt that's 60% polyester and 40% cotton has penalties calculated separately for each material, then combined proportionally. A small adjustment reflects whether certification information is present in the product data.
Why don't you publish the exact weights and raw penalty inputs?
The exact weightings and penalty values are revised continuously as new research is incorporated, so a published table would be stale and misleading almost immediately. They're also the core of the analysis engine we build and maintain. What we commit to publishing is everything needed to interpret a score: the six factors, how penalties combine, where the data comes from, and what the score can and cannot tell you.
Where does the materials data come from?
Our materials database is compiled from peer-reviewed research on textile health impacts, environmental assessments, and industry standards bodies. We regularly update penalty values as new research becomes available. When studies conflict, we err on the side of caution.
What's a "good" score?
There's no universal threshold. A score of 80+ generally indicates fewer potential health concerns. A score of 50-79 is typical for many synthetic blends. Below 50 suggests more factors to consider. Context matters: a performance athletic shirt might score lower due to synthetic materials, but those materials serve a purpose. The score helps you understand tradeoffs, not make the decision for you.
What are the limitations?
We can only analyze what's disclosed. If a product page doesn't list materials or certifications, we can't factor them in. We don't currently test products in a lab — our analysis is based on stated materials and the known properties of those materials. Scores estimate potential concerns; they're not medical advice.
How often is the methodology updated?
We add new materials as we encounter them and update existing entries when new research is published. If we analyze a product with a material we don't recognize, we flag it for review rather than guessing.
See the Score in Action
Paste any product URL to see its material breakdown and score, or read more about Greener Closet.
Analyze a Product