Simulate workplace exposure with ECETOC TRA
Model inhalation and dermal exposure for each component in a mixture using the ECETOC TRA 3.2 method.
The ECETOC TRA 3.2 exposure simulation calculates predicted workplace exposure levels for each substance in a mixture. It compares these against occupational exposure limits (OELs) to produce risk characterisation ratios (RCRs), helping you decide whether existing controls are adequate or need strengthening.
Run an exposure simulation
Open any product from your library and navigate to the Simulate page. The wizard has five steps.
Step 1: Set up the product
Select the Physical State (liquid or solid) and enter the Dilution (%). Use 100% for undiluted products.
Step 2: Select a component
Choose which substance in the mixture to assess. Each component shows its name, CAS number, and concentration. Components missing required data (such as molecular weight) are flagged with a warning icon.
Step 3: Enter component properties
Provide or confirm the physical properties NextSDS needs for the calculation:
- For liquids: molecular weight (g/mol) and vapour pressure (Pa)
- For solids: dustiness level (low, medium, or high)
Optionally select an OEL country and enter exposure limits: long-term inhalation (mg/m³), long-term dermal (mg/kg/day), local dermal (µg/cm²), and short-term inhalation (mg/m³). These limits are used to calculate risk characterisation ratios in the results.
Step 4: Define the use scenario
Describe how the product is used in your workplace:
- Process Category (PROC): select from 25 standard European process categories (PROC 1–25), ranging from closed processes to open spraying
- Use Type: industrial or professional
- Exposure Duration: under 15 minutes, 15 minutes to 1 hour, or over 4 hours
- Ventilation: outdoors, indoor with no ventilation, good ventilation, or enhanced (mechanical) ventilation
- Local Exhaust Ventilation: whether LEV is used for inhalation and/or dermal protection
- PPE: respiratory protection efficiency (none, 90%, or 95%) and glove efficiency (none, 80%, 90%, or 95%)
Select Calculate Exposure to run the simulation.
Step 5: Review results
The results table shows predicted exposure values and RCRs for each substance:
| Column | What it shows |
|---|---|
| 8-Hour Exposure | Predicted inhalation (mg/m³), dermal (mg/kg/day), and local dermal (µg/cm²) values |
| Short-term Exposure | Predicted inhalation and local dermal values for peak exposures |
| RCR | Risk characterisation ratio: predicted exposure divided by the OEL |
RCR values are colour-coded:
- Green (below 0.8): exposure is well within the limit
- Yellow (0.8–1.0): exposure is close to the limit
- Red (above 1.0): exposure exceeds the limit; additional controls are needed