Toxicological Threshold Risk Scoring for Non-Intentionally Added Substances in Recycled Polymers
Toxicological threshold scoring maps unidentified polymer migrates to Cramer exposure limits, mandating genotoxic screening below 0.00015 mg/kg food.
Schymanski Confidence Levels
Meaning
Classification frameworks assign a degree of certainty to the identification of an unknown chemical compound based on the available analytical evidence. Using schymanski confidence levels allows researchers to communicate how well they have identified a substance found in a polymer sample.
Identification Certainty
The highest rank indicates a confirmed match where the exact structure is verified by a reference standard. At the lowest rank of the scale, only the exact mass of the molecule is known. This system provides a transparent way to report results when a perfect match is not possible.
Database Matching
Analytical software compares the fragments of a molecule against libraries of known additives and contaminants. While a high score suggests a likely identity, schymanski confidence levels require more than just a statistical match for the higher ranks.
Structural Confirmation
Reaching the top rank of the framework requires multiple pieces of evidence, such as fragmentation patterns and retention times. If a lab cannot obtain a reference standard, the result stays at a lower rank within the schymanski confidence levels to avoid overstating the result. This cautious approach prevents incorrect safety assessments based on uncertain data.
The system is now a standard requirement for reporting non-targeted analysis in plastics.