We used an occupational exposure model to evaluate the CM. See below the information extracted of the model and the entities/attributes plotted to accommodate the model inputs/outputs.
We will include this in the template shared by Jasper.
Advanced REACH Tool (ART)
General
• Model type: mechanistic-statistical model
• Domain: occupational
• Population: individual worker
• Exposure route: inhalation (in worker's personal breathing zone)
• Substance / product: powders, solid objects, low-volatile liquids, volatile liquids
• Model components: sources, local control influence region (LCIR), source enclosure, near-field, far-field, personal enclosure, surfaces, receptor
•
Inputs
• Exposure duration (in minutes per activity per shift)
• Locations: Indoors or outdoors
• Distance from emission source: Near-field (<1m) / Far-field
• Sources: Described as “Activity classes” that are applied to describe scenarios for solids and liquids:
o Solid objects, e.g. fracturing & abrasion (2 scenarios)
o Powders & granules, e.g. transfer of powders (7 scenarios)
o Liquids, e.g. spray application of liquids (6 scenarios)
• Principal modifying factors (exposure factors / determinants)
o Activity emission potential, e.g. use rate, pressure, agitation, dropping height
o Substance emission potential, e.g. weight fraction, dustiness, volatility
o Local controls, e.g. local exhaust ventilation
o Segregation of sources
o Dilution, e.g. mechanical room ventilation
o Separation, e.g. personal enclosures
o Surface contamination / fugitive emissions
o Secondary sources, e.g. additional emission source in vicinity
•
Outputs
• Air concentration in worker's personal breathing zone (excluding effect of respiratory protection)
• Estimated exposures: dust, vapours and mists
• Estimates a combination of near-field exposure (NF) and far-field exposure (FF) incl. secondary sources
• Metrics: mg/m3
• Estimated inhalation exposure
o Activity
o Shift (incl. multiple activities per shift and time of non-exposure during a work shift)
o Longterm
• Percentile: 50, 75, 90, 95, 99
• Confidence interval: inter-quartile, 80, 90, 95
• We are not including the direction or type of relationships in the arrows for now.
• As indicated with the dashed line, using the occupational models there seems to be a direct link between Emission source – Exposure event – Estimated exposure level – Exposure target.
Some deviations on current conceptual model
• Rather explicitly define Exposure level as a Predicted exposure level. Consider adding Outcome type to indicate the granularity level of an exposure level
• We miss ‘exposure factors’ – especially linked with the emission source and substance
• A clear definition of emission source is required – in relation to exposure sources and pathways.
• We haven’t added ‘Scenario’ for now – not sure if it useful since it is a combination of various entities and attributes.
• Definition of a substance (ART defines classes not chemicals)
We used an occupational exposure model to evaluate the CM. See below the information extracted of the model and the entities/attributes plotted to accommodate the model inputs/outputs. We will include this in the template shared by Jasper.
Advanced REACH Tool (ART)
General • Model type: mechanistic-statistical model • Domain: occupational • Population: individual worker • Exposure route: inhalation (in worker's personal breathing zone) • Substance / product: powders, solid objects, low-volatile liquids, volatile liquids • Model components: sources, local control influence region (LCIR), source enclosure, near-field, far-field, personal enclosure, surfaces, receptor •
Inputs • Exposure duration (in minutes per activity per shift) • Locations: Indoors or outdoors • Distance from emission source: Near-field (<1m) / Far-field • Sources: Described as “Activity classes” that are applied to describe scenarios for solids and liquids: o Solid objects, e.g. fracturing & abrasion (2 scenarios) o Powders & granules, e.g. transfer of powders (7 scenarios) o Liquids, e.g. spray application of liquids (6 scenarios) • Principal modifying factors (exposure factors / determinants) o Activity emission potential, e.g. use rate, pressure, agitation, dropping height o Substance emission potential, e.g. weight fraction, dustiness, volatility o Local controls, e.g. local exhaust ventilation o Segregation of sources o Dilution, e.g. mechanical room ventilation o Separation, e.g. personal enclosures o Surface contamination / fugitive emissions o Secondary sources, e.g. additional emission source in vicinity •
Outputs • Air concentration in worker's personal breathing zone (excluding effect of respiratory protection) • Estimated exposures: dust, vapours and mists • Estimates a combination of near-field exposure (NF) and far-field exposure (FF) incl. secondary sources • Metrics: mg/m3 • Estimated inhalation exposure o Activity o Shift (incl. multiple activities per shift and time of non-exposure during a work shift) o Longterm • Percentile: 50, 75, 90, 95, 99 • Confidence interval: inter-quartile, 80, 90, 95
• We are not including the direction or type of relationships in the arrows for now. • As indicated with the dashed line, using the occupational models there seems to be a direct link between Emission source – Exposure event – Estimated exposure level – Exposure target. Some deviations on current conceptual model • Rather explicitly define Exposure level as a Predicted exposure level. Consider adding Outcome type to indicate the granularity level of an exposure level • We miss ‘exposure factors’ – especially linked with the emission source and substance • A clear definition of emission source is required – in relation to exposure sources and pathways. • We haven’t added ‘Scenario’ for now – not sure if it useful since it is a combination of various entities and attributes. • Definition of a substance (ART defines classes not chemicals)