
Ecotoxicity Hazard Assessment Framework
Assess chemical ecotoxic hazards using structured protocols and species sensitivity data
What You Can Do
You can conduct comprehensive ecotoxicity hazard assessments that integrate acute and chronic toxicity data, species sensitivity distributions, bioaccumulation potential, and environmental persistence into defensible risk characterization documents. The framework guides you through the full assessment pipeline—from data compilation and critical study evaluation through hazard classification, reference value derivation, and uncertainty quantification—while meeting ECHA REACH guidelines, EPA protocols, and international ecotoxicity standards.
Features
derive hazardous concentration values (HC5) with confidence intervals for multiple aquatic and terrestrial species
calculate Predicted No-Effect Concentrations for freshwater, marine, soil, and sediment compartments with assessment factors
evaluate persistence, bioaccumulation, and environmental mobility using REACH-compliant protocols
assign Acute/Chronic aquatic toxicity categories (1, 2, 3) under CLP regulation based on empirical data
assess study quality, reliability, and relevance using Klimisch scoring and OECD guideline compliance
document and propagate assessment factor justifications, data gaps, and conservative assumptions
structure findings into ECHA dossier sections, EIA annexes, and EPA submission formats
Example Output
Example 1: Freshwater PNEC Derivation
Input: Acute LC50 data from Daphnia (0.5 mg/L), chronic NOEC from fish (0.08 mg/L), algae ErC50 (1.2 mg/L)
Output:
- Lowest chronic NOEC: 0.08 mg/L (fish 21-day study)
- Assessment factor: 10 (limited chronic data, one species class)
- PNEC freshwater: 0.008 mg/L
- Hazard classification: Acute Category 1 (LC50 ≤ 1 mg/L)
Example 2: Soil Hazard Assessment
Input: Earthworm LC50 (45 mg/kg dw), Collembola NOEC (12 mg/kg dw), plant germination EC50 (180 mg/kg dw)
Output:
- Species Sensitivity Distribution HC5: 8.3 mg/kg dw
- PNEC soil: 0.83 mg/kg dw (assessment factor 10)
- Chronic aquatic hazard: Category 2 (H411)
- Data gap: Avian dietary toxicity study recommended
Example 3: Environmental Fate Summary
Input: log Kow 3.2, DT50 soil 45 days, BCF fish 280
Output:
- Persistence: Not persistent (DT50 <120 days)
- Bioaccumulation: Potential bioaccumulator (BCF 100–2500)
- Mobility: Mobile in soil (log Kow 3–4 range)
- Environmental concern: Moderate risk in aquatic systems with limited soil accumulation
What's Included
- SKILL.md: Complete ecotoxicity assessment protocol with decision trees for data evaluation and hazard classification
- Species Sensitivity Distribution (SSD) Template: Structured worksheet for compiling toxicity data, calculating HC5, and documenting assessment factors
- PNEC Derivation Checklist: Step-by-step guidance for selecting appropriate NOECs/LOECs, applying assessment factors, and documenting uncertainty
- Hazard Classification Matrix: Quick-reference table for CLP acute/chronic aquatic toxicity categories based on empirical thresholds
- Environmental Fate Assessment Framework: Evaluation protocol for persistence, bioaccumulation, mobility with regulatory interpretation guidance
Who It's For
- Environmental toxicologists and ecotoxicologists evaluating chemical hazards for regulatory compliance
- REACH Competent Body assessors and chemical manufacturers preparing substance dossiers
- Environmental consultants conducting Environmental Impact Assessments (EIA) for industrial projects
- Pesticide and pharmaceutical developers supporting ecotoxicity data packages
- Contaminated site remediation specialists assessing ecological risk from legacy chemicals
Best For
- New chemical substance ecotoxicity assessments under REACH Annex VIII/IX
- Deriving Predicted No-Effect Concentrations (PNEC) for freshwater, marine, and soil compartments
- Evaluating hazard classification under CLP regulation (Aquatic Toxicity categories)
- Retrospective analysis of contaminated site or field ecotoxicity data
- Comparative ecotoxicity assessments for chemical alternatives or formulation optimization







