Table of contents Text S1. Terminology according to ECHA R.14 3 Text S2. Data requirements for exposure modeling and emission source characterization 4 Text S3. Generation rate 6 Text S4. Air mixing flow rate between NF and FF, β 7 S4.1 Brief description of a Near-Field/Far-Field (NF/FF) model 7 S4.2 Approximation methods 7 S4.3 Approximation methods applicability for powder pouring measurements 8 S4.4 Setting the mean random air speed and near field volume flow rate 8 References 9 Appendix S1. Simulation of NF flow rate 10 Appendix S2. No. 1: Observed scenario 12 Appendix S3. No. 2: G range increased by ×2 15 Appendix S4. No. 3: β decreased by ×2 18 Appendix S5. No. 4: AER reduced by ×5 to 0.4 to 1.6 1/h 21 Appendix S6. No. 5: A small room (Vroom = 100 m3) 14 Appendix S7. No. 6: NF including LEV at 9.6 m3/min 27 Appendix S8. No. 7: A large room (Vroom = 10 000 m3) 31 Appendix S9. No. 8: Worst-case: G increased, β decreased, AER decreased and small room 34 (Vroom = 100 m3)

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