This is a ready-to-use HBEL/PDE monograph template. It is the signed toxicological record that every cleaning limit and every share-versus-dedicate decision in a multi-product facility references. Replace every <<FILL: ...>> placeholder with your own specifics, and have it authored and signed by a qualified toxicologist, not by QA or the cleaning-validation team. A worked filled specimen follows so you can see the level of detail an inspector expects. Verify each cited regulation against the current source before you rely on it.
Document control header
| Field | Entry |
|---|---|
| Document title | Health-Based Exposure Limit Monograph, <<FILL: COMPOUND / PRODUCT NAME>> |
| Document number | <<FILL: HBEL-ID, e.g. HBEL-014>> |
| Version | <<FILL: version, e.g. 1.0>> |
| Effective date | <<FILL: effective date>> |
| Supersedes | <<FILL: prior version or "New">> |
| Author (qualified toxicologist) | <<FILL: name, credentials>> |
| Reviewed / approved by | <<FILL: role>> |
| Next review due | <<FILL: date or trigger>> |
1. Purpose
This monograph derives the permitted daily exposure (PDE), also called the acceptable daily exposure (ADE), for <<FILL: COMPOUND>> so it can serve as the health-based basis for cross-contamination control, cleaning-limit calculation, and the decision on whether the compound may be manufactured in shared facilities. The PDE is the maximum amount of the substance a person may be exposed to daily, over a lifetime, with no appreciable adverse health effect.
2. Substance identification
| Field | Entry |
|---|---|
| Compound / active | <<FILL: name>> |
| CAS number | <<FILL: CAS>> |
| Therapeutic class / mechanism | <<FILL: class>> |
| Clinical maximum daily dose | <<FILL: mg/day>> |
| Route(s) of clinical administration | <<FILL: oral / parenteral / inhaled / topical>> |
| Physical form and solubility (cleanability relevance) | <<FILL: notes>> |
3. Hazard identification and critical effect
Summarize the toxicological database and identify the critical effect that drives the limit (the most sensitive relevant adverse effect). State why this effect and this study were selected.
- Critical effect selected:
<<FILL: e.g. reversible hepatocellular hypertrophy>> - Pivotal study:
<<FILL: species, duration, design, reference>> - Point of departure (POD):
<<FILL: NOAEL / LOAEL / BMDL, value in mg/kg/day>> - Basis for POD choice:
<<FILL: why this endpoint is critical and most relevant>> - Pharmacological effect (if lower than the toxicological effect):
<<FILL: relevant pharmacological POD, if applicable>>
4. PDE calculation
The PDE is derived as POD times body weight, divided by the adjustment (uncertainty) factors:
PDE = (POD x BW) / (F1 x F2 x F3 x F4 x F5)
State each factor and justify it. Do not use defaults silently; a factor without a rationale is a common finding.
| Term | Value | Justification |
|---|---|---|
| POD | <<FILL: mg/kg/day>> | <<FILL: study and endpoint>> |
| BW (body weight) | <<FILL: 50 kg default>> | Guideline default unless justified otherwise |
| F1 (interspecies) | <<FILL: e.g. 5 for rat>> | <<FILL: species of pivotal study>> |
| F2 (individual variability) | <<FILL: default 10>> | <<FILL: rationale for any deviation>> |
| F3 (study duration) | <<FILL: 1-10>> | <<FILL: sub-chronic to chronic extrapolation, if any>> |
| F4 (severe effect) | <<FILL: 1-10>> | <<FILL: severity of the critical effect>> |
| F5 (LOAEL not NOAEL) | <<FILL: 1-10>> | <<FILL: applied only if POD is a LOAEL/BMDL>> |
Calculated PDE = <<FILL: value in mg/day or µg/day>>
Where a route correction is needed (for example a parenteral limit derived from an oral study), state the bioavailability assumption and the corrected PDE:
- Route correction applied:
<<FILL: yes/no; assumption; corrected value>>
5. Genotoxicity and carcinogenicity assessment
State the genotoxic/carcinogenic status explicitly, because a non-threshold mutagen is not controlled by the PDE model.
- Genotoxicity data:
<<FILL: Ames, in vitro, in vivo results>> - Classification:
<<FILL: non-genotoxic / genotoxic with threshold / genotoxic non-threshold>> - If non-threshold genotoxic, limit basis:
<<FILL: TTC default 1.5 µg/day per ICH M7 logic, or compound-specific acceptable intake with data reference>> - Sensitization / other route-specific hazard the PDE may not capture:
<<FILL: notes>>
6. Resulting limits and downstream use
| Output | Value | Notes |
|---|---|---|
| PDE (health-based limit) | <<FILL: mg/day>> | Feeds the MACO calculation |
| Limit basis for cleaning | <<FILL: HBEL-derived MACO governs; 1/1000-dose and 10 ppm may serve only as alert limits>> | Per the 2018 EMA Q&A |
| Occupational exposure banding (if derived) | <<FILL: OEB / OEL, or N/A>> | For containment design, separate from the PDE |
| Shared-facility relevance | <<FILL: e.g. low PDE, potent, favors dedicated parts>> | Informs the QRM decision |
7. Acceptance criteria for this monograph
The monograph is complete and defensible when all of the following are true:
- A qualified toxicologist authored and signed it, and the qualification basis is on file.
- The critical effect and pivotal study are stated with the rationale for their selection.
- Every adjustment factor carries an explicit justification.
- The genotoxic/carcinogenic status is stated, and non-threshold mutagens use a TTC or compound-specific basis, not a standard PDE.
- Route corrections, where relevant, are stated with their assumptions.
- A review trigger is defined so new toxicology data forces re-derivation.
8. References
EMA/CHMP/CVMP/SWP/169430/2012, Guideline on setting health-based exposure limits for use in risk identification in the manufacture of different medicinal products in shared facilities (effective 1 June 2015). EMA/CHMP/CVMP/SWP/246844/2018, Questions and Answers on implementation of risk-based prevention of cross-contamination (April 2018). EU GMP Chapters 3 and 5 (2015 revision). ICH M7(R2), Assessment and Control of DNA Reactive (Mutagenic) Impurities in Pharmaceuticals (for genotoxic compounds). ICH Q3C / Q3D adjustment-factor approach (methodological analogy for the PDE factors).
Confirm the current version and clause numbers of each reference before issue.
9. Revision history
| Version | Date | Author | Summary of change |
|---|---|---|---|
<<FILL: 1.0>> | <<FILL: date>> | <<FILL: toxicologist>> | Initial derivation. |
10. Approvals
| Role | Name | Signature | Date |
|---|---|---|---|
| Author (qualified toxicologist) | <<FILL>> | ||
| Independent toxicology review (if used) | <<FILL>> | ||
| Quality Assurance (process approval) | <<FILL>> |
Filled specimen
The following shows the monograph completed for an illustrative compound. The compound and numbers are fictional; replace them with your own.
| Field | Entry |
|---|---|
| Compound | Compound X (illustrative small-molecule active) |
| CAS number | 000000-00-0 (illustrative) |
| Therapeutic class | Kinase inhibitor |
| Clinical maximum daily dose | 200 mg/day |
| Critical effect | Reversible reduction in reticulocyte count, no severe pathology |
| Pivotal study | 26-week oral rat study, GLP, Study TX-2201 |
| POD | NOAEL 1 mg/kg/day |
| BW | 50 kg |
| F1 | 5 (rat to human) |
| F2 | 10 (human variability) |
| F3 | 1 (chronic-duration study, no extrapolation) |
| F4 | 1 (effect not severe, reversible) |
| F5 | 1 (NOAEL used) |
| PDE | (1 x 50) / (5 x 10 x 1 x 1 x 1) = 1 mg/day |
| Genotoxicity | Negative Ames and in vitro micronucleus; non-genotoxic |
| Limit basis | HBEL-derived MACO governs cleaning limits; historical 1/1000-dose retained only as an alert limit |
| Shared-facility relevance | PDE of 1 mg/day is moderate; sharing is defensible if detectability and cleanability gates pass |
In this specimen the toxicologist selected a reversible, non-severe hematologic effect as critical, applied only interspecies and human-variability factors because the study was chronic and the effect mild, confirmed the compound is non-genotoxic so the PDE model applies, and produced a 1 mg/day PDE that flows directly into the MACO calculation. That chain, from study to endpoint to factors to PDE to cleaning basis, is exactly what an inspector traces.
Common inspection findings this record prevents
- A “PDE” used in cleaning-limit calculations that no qualified toxicologist ever derived or signed.
- Adjustment factors applied with no stated justification.
- A genotoxic compound limited with a standard PDE instead of a TTC or compound-specific acceptable intake.
- A monograph that exists but was never reconciled to the cleaning limits actually in use on the floor.
- No review trigger, so the monograph goes stale as new toxicology data appears.
How to adapt this record
- Have a qualified toxicologist author and sign it; keep their qualification evidence on file.
- Fill the substance identification and pull the pivotal study and POD from the toxicology database.
- Justify every adjustment factor in the table; do not leave a default unexplained.
- State the genotoxic status explicitly and switch to a TTC/compound-specific basis if the compound is a non-threshold mutagen.
- Feed the PDE into the MACO worksheet and confirm the floor limits on the SOP match this monograph.
- Set a review trigger tied to new data and to the periodic-review cycle.