Permitted Daily Exposure (PDE) / Acceptable Daily Exposure (ADE)

A scientifically derived health-based exposure limit used in pharmaceutical risk identification, including cross-contamination and shared-facility assessments.

What PDE means

A substance-specific daily exposure threshold.

The EMA health-based exposure limit guideline describes PDE as a substance-specific dose that is unlikely to cause an adverse effect if an individual is exposed at or below the dose every day for a lifetime.

A PDE is derived from a structured review of available pharmacological and toxicological data. The assessment identifies critical effects, selects an appropriate point of departure, and applies adjustment factors to address relevant uncertainties.

HazardIdentify relevant pharmacological and toxicological effects

PODSelect NOAEL or another justified point of departure

AdjustmentAccount for extrapolation and uncertainty

Core derivation logic

What goes into a PDE assessment?

Hazard identification

Review relevant non-clinical and clinical information, including pharmacology, repeat-dose toxicity, carcinogenicity, genotoxicity, reproductive/developmental toxicity and known clinical adverse effects, as applicable.

Critical-effect selection

Identify the most relevant adverse or clinically meaningful effects and select the point of departure that appropriately represents the critical effect.

Adjustment factors

Apply justified uncertainty / assessment factors for areas such as interspecies extrapolation, human variability, study duration and severity of toxicity, where appropriate.

Clinical dataGood-quality human data can be highly relevant and may influence the basis of a health-based limit.

RouteRoute-to-route extrapolation may require correction where bioavailability differs materially.

OutputThe final value should be justified in relation to the intended use, exposure context and applicable framework.

Pharmaceutical use

Why companies use PDE / ADE values.

Health-based exposure limits can be used to identify and manage risks from residual active substances in shared manufacturing environments and can support carryover or cleaning-validation acceptance criteria.

The exact terminology and implementation can differ by organisation and jurisdiction; the underlying toxicological rationale should remain explicit.

Scientific documentation

What a ToxWriter assessment can cover.

Hazard and pharmacology review
Critical-effect and point-of-departure rationale
Adjustment-factor justification
Route and clinical-data considerations
Final health-based exposure limit documentation

Primary references

EMA HBEL / PDE guideline ICH Q3C(R9) — Residual solvents ICH Q3D(R2) — Elemental impurities ICH impurity-risk and OSHA references

The EMA HBEL guideline is relevant to substance-specific HBEL/PDE derivation for shared-facility risk identification. ICH Q3C and Q3D provide PDEs for residual solvents and elemental impurities, respectively; those impurity-specific values have a defined scope.

Request PDE / ADE support

Share the API and intended exposure context.

We can scope the toxicological assessment and documentation needed for the intended manufacturing or regulatory use.

Contact ToxWriter →