With the dramatic increase of nano-enabled products entering the market every year, human and environmental exposures are inevitable, which raises concerns in terms of the health and safety of such emerging nanomaterials. Scientific knowledge to assess the exposure to nanomaterials continues to improve. As an example, new exposure tools and models for nanomaterials are being developed. To further promote the development in this area, the OECD compiled an inventory of available models and tools for assessing occupational, consumer and environmental exposure to Nanomaterials. 54 tools and models were initially compiled and following in-depth analyses, 10 occupational, 7 consumer and 6 environmental tools/models were recommended or evaluated as suitable for assessing exposure to nanomaterials. The detailed information on the analyses and evaluations are provided in the reports accessible from the Series on Nanomaterials website (No. 98, 99, 100 and 101). The OECD hosted a webinar on 2 December at 14:00 CET. to present the key findings of the reports. Watch the webinar replay at https://oe.cd/testing-assessment-webinars

1. December 2, 2021
Mathieu Dextraze and Marc LaPointe
WEBINAR:
Compilation and evaluation of available tools and
models used for assessing environmental
exposure to manufactured nanomaterials - project
and final report
WPMN

2. Marc
• Context
– Nanomaterial
environmental risk
assessment
• Background
– Purpose
• Process
– Objective 1
– Objective 2
2021/12/02
Outline for the webinar
Mathieu
• Report structure and use
1. Background and
Purpose
2. Inventory and
Prioritization of tools
and models
3. Methodology
4. Assessments and
Analyses
5. Recommendations
6. Conclusion
2 /20

3. Context - Environmental risk assessment and exposure
• Changing identity and
chemistry according to
environmental conditions.
• Persistence and (partial)
degradation in the
environment.
• Estimating presence in
the environment using
computer simulation
models.
2021/12/02
Exposure Considerations:
3 /20

4. 4 /20
Context - Exposure assessment of nanomaterials
2021/12/02
Atmospheric dispersion
Deposition
Sedimentation
Biosolids application/
discharge to soil
Industrial
releases
Household
products
Long-range
transport
Leaching to
groundwater
Release from
wastewater
treatment
Surface water
recharge
Releases
(quantities
generally known)
Deposition -
environmental fate of
persistent
nanomaterials
(quantities unknown)
Environmental behavior
changes due to transformation
products, disassociation,
dissolution, agglomeration,
etc.
Data gaps for nanomaterials

5. Background
2015 Survey
Projects that arose from a
survey within the Working
Party on Manufactured
Nanomaterials (WPMN)
Steering Group on Exposure
Mitigation that identified
nanomaterial environmental
and consumer exposure
models and tools and their
importance as they relate to
the enhancement of the
regulatory risk assessment of
nanomaterials.
2017 Proposal
Canada proposed projects to
compile and evaluate
available tools and models to
be lead by Environment and
Climate Change Canada
(ECCC), and Health Canada
2019 Compilation
ECCC began the compilation
of available tools and models
for the assessment of
environmental exposure to
manufactured nanomaterials
produced a list of priority
models for evaluation
2020 Evaluation
Evaluation of the applicability
of the compiled models to
regulatory exposure
assessment of manufactured
nanomaterials
2021 Report
2021/12/02
5 /20

6. Purpose
2021/12/02
To provide guidance on the availability and the
applicability of environmental exposure modeling
tools that may be used for regulatory risk assessment
of manufactured nanomaterials.
• To identify the existing tools and models for estimating the
environmental exposure to nanomaterials
• To enhance comprehension and determine the reliability of
the tools
• To enhance the transparency and decision-making power
of exposure assessments
• To provide an organized compilation of input parameter data
6 /20

7. Process
2021/12/02
Objective 1:
Inventory and
prioritization of
modeling tools
• 24 tools identified  10 tools prioritized for evaluation
• prioritized according to criteria such as domain, scope, kinetics, supporting
documentation, and availability of input parameters.
Name Type*
DPMFA MFA
LearNano MFA
nanoRelease MFA
SimpleBox4 EFM
nanoFate EFM
MendNano EFM
Rhone/Rhine River
nanonanoDUFLOW River
WASP8 River
WASP7 River
*3 types of models - Materials Flow
Analysis (MFA) models,
Environmental Fate Models (EFM)
and spatially explicit river models
7 /20

8. 8 /20
MFA vs EFM vs River
2021/12/02
Atmospheric dispersion
Deposition
Sedimentation
Biosolids application/
discharge to soil
Industrial
releases
Household
products
Long-range
transport
Leaching to
groundwater
Release from
wastewater
treatment
Surface water
recharge
River
MFA
EFM

9. Process
2021/12/02
Objective 2:
Evaluation
and analysis
• Functional Assessment
• 2 tools rejected due to a lack of source code (8 tools now considered)
• Assessment of model functionality and input parameters
• Statistical analysis
• Uncertainty and sensitivity analysis
• Data Requirements
• Recommendations/Report
• Recommendations on the practicality of each model to environmental risk assessment
Final report
Name Type*
DPMFA MFA
LearNano MFA
nanoRelease MFA
SimpleBox4 EFM
nanoFate EFM
MendNano EFM
Rhone/Rhine River
nanonanoDUFLOW River
WASP8 River
WASP7 River
FUNCTIONAL ASSESSMENT
Contained two sub components to
analyze the selected models:
Mechanistic
Assessment:
• Computer
requirements
• Installation
• Usage
Theoretical
Assessment:
• Assumptions
• Algorithms
• Input Parameters
• Model Output
STATISTICAL ANALYSIS
Uncertainty
analysis:
• Monte Carlo
Simulations
(MCS)
Systematic
sensitivity analysis
• standardized
sensitivity score
9 /20

10. 1. Background and Purpose
2. Inventory and Prioritization of tools and models
3. Methodology
4. Assessments and Analyses
5. Recommendations
6. Conclusion
10 /20
The Report – Sections Overview
2021/12/02

11. • This section is useful for finding summary information
about the tools and models that were compiled or
evaluated.
• Provides details on:
– The compilation of tools and models
– The model types in the inventory (MFA, EFM, River)
– The criteria for prioritization of tools and models for evaluation
– A summary of the models prioritized for evaluation
11 /20
The Report – 2 Inventory and Prioritization of tools
and models
2021/12/02

12. • This section is useful to answer questions about how the
models were evaluated
• Describes the details of the methodologies for:
– The functional assessment:
• Applicability Criteria
• Difficulty Scale
– The statistical analysis:
• Selection of tested parameters and description of scenarios
• Uncertainty analysis
• Sensitivity analysis
12 /20
The Report – 3 Methodology
2021/12/02

13. 13 /20
The Report – 4 Assessments and Analyses:
Functional Assessment Example From DPMFA
2021/12/02

14. 14 /20
The Report – 4 Assessments and Analyses:
Uncertainty Analysis Example From DPMFA
2021/12/02

15. 15 /20
The Report – 4 Assessments and Analyses:
Sensitivity Analysis Example From DPMFA
2021/12/02

16. 16 /20
The Report – 4 Assessments and Analyses:
Sensitivity Analysis Example From DPMFA
2021/12/02

17. • This section is useful to choose a model for an exposure
assessment
• Recommendations for models based on:
– Functional assessment
– Uncertainty analysis
– Sensitivity analysis
• Overall recommendations
17 /20
The Report – 5 Recommendations
2021/12/02

18. 18 /20
The Report – 5 Recommendations
2021/12/02

19. • Includes a text-based summary of the results and general
conclusion of the current study
• Recommendations for further analysis in future studies
involving the models that were evaluated
• WPMN is considering preparing an operational guidance
document for the use of the models presented in this
report in risk assessment
19 /20
The Report – Conclusion

20. Thank you!
Questions?
Contact: nanotechnology-nanotechnologie@ec.gc.ca
Click the moose to link to the report, or…
https://www.oecd.org/chemicalsafety/testing/series-testing-assessment-publications-number.htm
Report on the series on testing and assessment # 345
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