Phytotoxicity Index
VC-MET-216 — a normalized 0–100 bioassay of extract potency against a standard target — the regulated activity index.
Definition
Phytotoxicity Index is a normalized 0–100 bioassay score expressing an extract's measured activity against a standardized reference target, relative to a calibrated potency ladder. It is the controlled, comparable activity figure on a lot's record.
Why it matters
The index is the regulated, comparable measure of how active a lot is, independent of which compound dominates. It governs classification, handling grade, and the controls applied under the facility's compliance regime.
Formula
PI = 100 · ( log(EC50_ref / EC50_lot) − a ) / b EC50_lot = lot half-maximal effect concentration EC50_ref = certified reference ladder a, b = calibration constants of the assay Clamped to [0,100]; reported per batch with assay CV.
Inputs
| Input | Detail | Source |
|---|---|---|
| Bioassay | Standardized target response | Lab |
| Reference ladder | Certified potency standards | Lab |
| Calibration | Assay constants a, b | Lab |
Units & Scale
Dimensionless index 0–100, integer, per batch. Higher means more active; upper bands trigger tighter handling controls.
Sampling & Source
- Assayed per batch against the standardized target.
- Calibrated to the certified reference ladder each run.
- Result sets handling grade and compliance controls.
Thresholds
OK
WARN
CRIT
Recent Trend
Zone roll-up, last 14 sampling periods (current 62):
Interpretation Guidance
| Band | Reading | Likely Driver | Action |
|---|---|---|---|
| 40–75 | Expected | On-target activity | Standard handling grade. |
| 76–85 | Elevated | High-potency cultivar/cycle | Review controls. |
| 86–93 | WARN | Above envelope | Tighten controls; re-grade. |
| > 93 | CRIT | Maximum activity | Top handling grade; restricted access. |
Related Metrics
Alkaloid Concentration
Potency correlate.
VC-MET-212Secondary Metabolite Diversity
Profile context.
VC-MET-401Containment Integrity Index
Facility safety.
VC-MET-217Extraction Purity
Cleanliness term.
Related SOPs
- Biocontainment compliance & classification — SOP Library.