Enhesa GHS+ Chemical Hazard Assessment framework overview

Enhesa GHS+ Chemical Hazard Assessment Process

Enhesa Sustainable Chemistry’s GHS+ process ensures a thorough and scientifically grounded Chemical Hazard Assessment (CHA). The steps below outline our standardized approach.

Step 1 – Confirm Chemical Identity

To begin a CHA, our toxicologists first verify the identity of the chemical using a set of accepted methods. This step ensures a reliable connection between the substance and its relevant data across physical-chemical, human health, and environmental endpoints.

Primary Identifier:

• CAS RN (Chemical Abstract Service Registry Number): The most widely used unique identifier, linking chemicals to data. While there are over 279 million CAS RNs, we focus on the ~400,000 relevant to consumer products and industrial applications in our SciveraLENS Chemical Data Repository.

Other Identifiers (if CAS RN is missing or conflicting):

• EC Number (ECHA)
• US EPA PMN (Pre-Manufacture Notification Number)
• SMILES notation (molecular structure)
• Other authoritative references

Accurate chemical identification ensures compatibility with regulatory lists, minimizes ambiguity from naming conventions, and supports the use of modeling tools and analog analysis.

Step 2 – Screen Against Chemical Lists

Next, we screen the chemical against a curated collection of 600+ lists within SciveraLENS, organized into:

• Regulatory Lists
• Authoritative Lists
• Restricted Substance Lists (RSLs)
• Screening Lists
• Watch Lists
• Preferred Lists
• Chemical Groups
• Informational/Inventory Lists

These lists help identify initial indications of concern for human or environmental health endpoints. List screening is not equivalent to a full hazard assessment. While helpful for early prioritization, only a full assessment can determine the true hazard profile.

Many lists flag groups of chemicals (e.g., “mercury and its compounds”) rather than individual substances. Our team maps group listings to specific chemicals—a complex but essential task to provide clarity for users.

View the full roster of 600+ lists available.

Step 3 – Endpoint-Level Hazard Assessment

Toxicologists assess each endpoint using multiple data types:

• Authoritative Lists
• Regulatory Lists
• Experimental Data
• Modeled Data
• Analogous Data
• Expert Judgment

Data Sources Include:

• NIH/NLM (e.g., PubChem)
• ECHA REACH dossiers
• US EPA databases
• NTP reports
• IARC monographs
• ToxPlanet
• Peer-reviewed literature

Modeling Tools:

• OECD QSAR Toolbox
• US EPA EpiSuite
• US EPA T.E.S.T.
• PBT Profiler (referenced but no longer supported)

Best Practices:

• Analog Read-Across: Used when direct data is missing.
• Expert Judgment: Toxicologists assess data quality and consistency.
• Data Reliability: High-quality experimental data is preferred. Klimisch scores and other indicators are used, but expert review is central.
• Weight-of-Evidence: When data conflict, we apply a precautionary principle, classifying at the highest supported hazard level.

Endpoints Assessed in the GHS+ Chemical Hazard Assessment

We evaluate three endpoint categories: Human Health, Environmental Health, and Physical-Chemical Properties. Each includes Core and Supplemental endpoints.

Human Health Endpoints

Core Endpoints

Required for an overall hazard category other than “Gray” (i.e., insufficient data):

• Carcinogenicity
• Mutagenicity / Genotoxicity
• Developmental Toxicity
• Reproductive Toxicity
• Endocrine Activity

Supplemental Endpoints

Contribute to the hazard profile; data gaps are permitted:

• Acute Oral Toxicity
• Acute Dermal Toxicity
• Acute Inhalation Toxicity
• Respiratory Sensitization
• Dermal Sensitization
• Dermal Irritation
• Eye Irritation
• Systemic Toxicity (Single and Repeat Dose)
• Neurotoxicity (Single and Repeat Dose)
• Sensory Irritation
• Aspiration Potential

To avoid a “Gray” score, all Core Human Health Endpoints must be conclusively assessed. Supplemental endpoints support the overall picture but are not all mandatory for a conclusive score.

Environmental Health Endpoints

Core Endpoints

Required for a conclusive overall environmental hazard category:

• Persistence
• Bioaccumulation
• Acute or Chronic Aquatic Toxicity

Supplemental Endpoint

• Mobility (assessed and documented; not factored into scoring)

Supplemental Physical-Chemical Endpoints

• Flammability
• Reactivity
• Environmental Transformation Products

If a transformation product is persistent, bio-accumulative, or toxic, it may affect the scoring of related endpoints like Persistence or Toxicity.

Hazard Communication: The GHS+ Traffic Light System

Each endpoint and overall hazard assessment is communicated using a color-coded system.

Table 2-1: SciveraLENS GHS+ Endpoint-Level Hazard Assessment Conditions

Color Code	Hazard Level	Meaning
Green	Low Hazard	Indicates a low hazard for the specific endpoint or overall chemical.
Yellow	Moderate Hazard	Indicates a moderate hazard.
Red	High Hazard	Indicates a high hazard.
Black	Very High Hazard	Indicates a very high hazard.
Gray	Insufficient Data	Data are insufficient for assessment.
Blue	Assessment in Progress	No concerns found during list screening; assessment not yet complete.
Half-Gray	Modeled/Analog Data	Indicates use of modeled, analogous, or expert judgment data in the score.

This traffic light system provides a clear, intuitive way to interpret chemical hazard assessments at both the endpoint and overall level.

Step 4 – Overall Chemical Hazard Categorization

While individual endpoint results provide detailed insight into hazard type and severity, an overall hazard category enables efficient comparison, prioritization, and alternatives assessment.

To assign this category, Enhesa Sustainable Chemistry uses a rules-based system implemented in SciveraLENS. The system evaluates all endpoint-level assessments to determine the Overall Hazard Category.

SciveraLENS Overall Chemical Hazard Categories and Rules

Category	Criteria
Green – Preferred	– All endpoints show conclusive or limited-evidence low hazard – No data gaps for Core or Supplemental Endpoints
Green/Yellow – Acceptable Chemical	– All Human Health Core Endpoints are low hazard with no data gaps – One or more Supplemental Endpoints are moderate hazard – One Environmental Fate Endpoint may be high if others are low – No endpoints show very high hazard – No more than three Supplemental data gaps
Yellow – Conditional Chemical	– One or more Supplemental Endpoints are high or very high hazard – No Core Endpoints are high or very high hazard – No Environmental Fate Endpoints are high if paired with moderate Human Health or Ecotoxicity hazards – No more than three Supplemental data gaps – No Core data gaps
Red – High Concern	– One or more Human Health Core Endpoints are high or very high hazard, or – Two or more Environmental Health Core Endpoints are high or very high hazard (e.g., Persistence + Bioaccumulation), or – Very High Persistence or Bioaccumulation combined with very high acute or high chronic Human Health hazards
Gray – Insufficient Data to Assess	– One or more Core Endpoint data gaps, or – Four or more Supplemental Endpoint data gaps

Step 5 – Quality Assurance & Verification

GHS+ hazard assessments are completed within our Chemical Data Repository (CDR), the engine behind SciveraLENS. Key QA features include:

• Quantitative scoring integration for endpoints like acute and aquatic toxicity

• Source tracking to document all reviewed references

• Workflow stages based on endpoint types (e.g., CMRD, PBT) and status (Research → Assess → QA → Complete)

• Dual review process: A board-certified toxicologist performs a full second review before finalizatio

Once verified, the hazard assessment is marked “Complete” and fully aligned with the GHS+ framework.

Enhesa Sustainable Chemistry continuously improves the GHS+ methodology ensuring the framework evolves with new science and stakeholder input.

Step 6 – Ongoing Maintenance

Hazard assessments are actively maintained through a structured, recurring update process:

• List monitoring and updates propagate automatically across affected chemicals

• New hazard data is evaluated and used to revise endpoint scores

• User alerts notify SciveraLENS users of changes to chemicals of interest

References

• US Environmental Protection Agency Design for Environment Program
  Alternatives Assessment Criteria for Hazard Evaluation, Version 2.0 (2011)

• National Academy of Sciences
  A Framework to Guide the Selection of Chemical Alternatives (2014)

• United Nations
  Globally Harmonized System (GHS) of Classification and Labelling of Chemicals, 10th Revised Edition (2023)

• NSF International / Green Chemistry Institute / American National Standard
  NSF/GCI/ANSI 355 – 2011: Greener Chemicals and Processes Information
  (May require purchase or institutional access)

• Global Electronics Council & TÜV Rheinland
  Criteria for the Sustainability Assessment of Network Equipment for the EPEAT® Ecolabel and TÜV Rheinland Green Product Mark (2021)
  (Specific criteria documents are available via GEC’s EPEAT website or through partner certification bodies)

Appendix A: SciveraLENS GHS+ Chemical Hazard Assessment Framework – Criteria by Endpoint

Human Health Endpoints – Chronic