PDE / AL / OEL Screening Calculator — Non-Mutagenic Impurities

Transparent methodology ICH aligned ECHA R.8 principles

1) Output Type & Point of Departure

Output type

PoD type

PoD unit

PoD value

Selection hierarchy: BMDL preferred; if no reliable BMDL → NOAEL; if no NOAEL → LOAEL.

2) Gas Concentration Conversion (ppm ↔ mg/m³ ↔ mg/L)

3) Inhalation Concentration → mg/kg/day

4) Body Weight Inputs

Human body weight (PDE/AL)default 50 kg

Worker body weight (OEL)default 70 kg

5) Assessment Factors (AF1–AF7)

AF1 (F1) — Species extrapolation

Calculate AF1 from body weights (surface area scaling)

AF2 (F2) — Human variability

Fixed at 10 for PDE/AL (general population). Switches to 5 for OEL (worker scenario).

AF3 (F3) — Duration extrapolation

Override AF3 (advanced; integer 1–10)

AF4 (F4) — Severity of toxicity

AF5 (F5) — Absence of BMDL/NOAEL

Override AF5

Rules: BMDL → AF5 = 1 (locked). NOAEL → default 1. LOAEL → AF5 ≥ 2 (default 5).

AF6 (F6) — Route-to-route / Bioavailability

Does the intended route differ from the PoD study route?

Select route-to-route approach

AF7 (F7) — Read-across uncertainty

6) Results & Transparency

Enter all required inputs and click "Calculate PDE/AL/OEL". The calculator will show the selected PoD, all AF values, the total factor product, the substituted equation, and the final result.

Disclaimer: This is an educational screening tool for non-mutagenic impurities, using PDE/AL-style adjustment factors and inhalation dose conversion principles aligned with ICH and ECHA R.8 guidance documents. It is intended for preliminary assessment only and does not replace expert toxicological evaluation of study design, exposure assumptions, toxicokinetics, endpoint relevance, local respiratory effects, or uncertainty. If an EU IOEL, EU BOEL, or national OEL exists, that value takes precedence for workplace risk management. For mutagenic impurities (including nitrosamines), use the separate Nitrosamine AI Calculator.