* = median of 10 000 MonteâCarlo runs (0â100 scale). Scores â„ 80 = Highârisk (red band). Takeaway: The list is dominated by persistent, bioâaccumulative, and/or highly toxic substances that appear in multiple exposure pathways (air, water, food, occupational). 5ïžâŁ How to Use This List in Your Own ESRA Projects | Step | Action | Practical tip | |------|--------|----------------| | 5.1 | Import CHEMAL GEGG data into your ESRA software (most accept CSV). | Ensure the column headings match the modelâs CAS , UseâCategory , EmissionâRate fields. | | 5.2 | Select relevant exposure scenarios (e.g., âUrban Industrialâ, âRural Agricultureâ). | You can drop the entire 20âchemical set or filter by sectorâspecific uses. | | 5.3 | Run baseline MonteâCarlo simulation (â„ 5 000 iterations). | Save the output as baseline_ESRA_scores.csv . | | 5.4 | Perform âWhatâIfâ analyses â e.g., 50 % reduction in emissions, substitution with a lowerârisk analogue, or implementation of a containment barrier. | Compare new scores against the baseline to quantify risk reduction. | | 5.5 | Communicate results using the colourâcoded risk band and a GIS heat map. | Stakeholderâfriendly visualisation = higher uptake of mitigation measures. | | 5.6 | Document uncertainties â highlight chemicals where the 95 % CI spans > 15 risk points (usually PFAS, PCBs). | Transparent reporting builds regulator confidence. | 6ïžâŁ RealâWorld Example: Municipal Wastewater Treatment Plant (WWTP) | Scenario | Key Findings | |--------------|-------------------| | Current emissions (baseline) | The ESRA score for the plantâs effluent is 84 (highârisk) â driven primarily by PFAS , BPA , and Nonylphenol ethoxylates . | | Mitigation 1 â Install PFASâadsorbing GAC filters | PFAS contribution drops 70 %, total ESRA score falls to 71 (mediumârisk). | | Mitigation 2 â Replace BPAâbased epoxy linings with BPAâfree alternatives | Additional 5âpoint reduction â 66 (still medium but approaching low). | | Combined (GAC + BPAâfree) | Final ESRA score 58 â Lowârisk (green). | | Costâbenefit | Capital cost â USD 2.2 M, but riskâreduction value (avoided health & ecosystem costs) estimated at USD 6.5 M/yr (based on WHO DALY valuations). |
Takeâaway : 7ïžâŁ Frequently Asked Questions (FAQ) | Q | A | |---|---| | Can I use the Topâ20 list for chemicals not on the list? | Yes, the ESRA model is generic. The list is a prioritisation shortcut ; for any other substance youâll need its own exposure & hazard data. | | Is the CHEMAL GEGG database free? | A core dataset (CAS, basic physâchem, production volume) is openâaccess via the EUâOpenChem portal. The full exposureâgrid (scenario coefficients) is available under a CreativeâCommons AttributionâNonCommercial license. | | What software can run ESRA? | Commercial: ESRAâPro , RiskQuant . Openâsource: OpenESRA (Pythonâbased, integrates with pandas / numpy ). | | How often is the Topâ20 updated? | Annually, using the latest REACH & TSCA submissions plus peerâreviewed toxicity data. | | What if my jurisdiction uses a different risk banding system? | ESRA scores are dimensionless; you can map them to any local banding (e.g., âTierâ1/2/3â) by setting custom cutâoffs. | 8ïžâŁ QuickâStart Cheat Sheet (Downloadable) | File | Description | |------|-------------| | ESRAâModelâTemplate.xlsx | Preâfilled with the Topâ20 CHEMAL GEGG data; just plug in your local emission rates. | | GEGGâScenarioâMatrix.pdf | Visual guide to the 12 exposure pathways and default scaling factors. | | RiskâCommunicationâPoster.png | Readyâtoâprint poster (A2) showing colour bands esra model chemal gegg 20 top
& the Topâ20 CHEMAL GEGG Chemicals (If youâre new to environmentalârisk modelling or just looking for a quick reference on the most hazardous chemicals in the ESRA framework, this post is for you.) 1ïžâŁ What Is the ESRA Model? | Feature | Description | |---------|--------------| | Full name | E nvironmental S ocial R isk A ssessment | | Purpose | Quantify the potential adverse effects of chemicals on human health, ecosystems, and socioâeconomic systems. | | Core pillars | 1ïžâŁ Exposure Assessment 2ïžâŁ Hazard Characterisation 3ïžâŁ Risk Characterisation 4ïžâŁ Uncertainty & Sensitivity Analysis | | Typical users | Regulators, chemical manufacturers, NGOs, academia, and insurance underwriters. | | Why it matters | Provides a transparent, reproducible, and scienceâbased score that can be used for prioritisation, permitting, and mitigation planning. | * = median of 10 000 MonteâCarlo runs (0â100 scale)