The casNumber is how piper matches analytes from different lab report formats to the same underlying chemical. When a lab report uses "Benzene" and another uses "Benzol", both resolve to the same casNumber (71-43-2). This makes casNumber the most reliable key for cross-referencing results against regulatory thresholds and for deduplication when importing multiple lab reports.
Technical section
Data model, API, and internals — visible to developers.