Second edition · September 2026 · regulatory cut-off 25 September 2026
Three impurity families, three limit logics: PDE, TTC and CPCA, with the source next to every number.
Q3D sets PDEs on a threshold toxicology basis; M7 sets a TTC or compound-specific AI at a theoretical 10⁻⁵ cancer risk; for N-nitrosamines, which belong to the cohort of concern, the limit is a specific AI, from data, read-across or the CPCA. A number from one logic is never used in another. This guide takes every impurity from source to limit, with the rules of the EU, the United States and other jurisdictions: 24 chapters in six parts, 227 pages in the English edition, 243 in the Italian, and 17 editable tools, for €129.
227 pages (ENG) · 243 (ITA) · A4 PDF24 chapters in six parts + 6 appendices17 editable tools: 10 Excel + 7 WordICH Q3D(R2) · ICH M7(R2) · N-nitrosamines6 jurisdictions116 sources in the register68 tracked decisions
Two separate editions: you choose the language. The guide and the toolkit exist as an English edition and as an Italian edition, identical in structure. Choose the ENG - English or the ITA - Italiano variant: the purchase gives access to the edition you choose.
Formerly sold as “Safety Guidelines ICH S”. Until September 2026 this guide was sold under that title, but its content has always covered ICH Q3D and ICH M7. The second edition adopts a title that describes the content: the ICH S series is not covered. If you bought the first edition, you receive this one at no extra cost.
The guide
24 chapters in six parts: legal force and the text that governs each impurity, ICH Q3D(R2) from scope to the calculation Options, ICH M7(R2) from (Q)SAR assessment to the control Options, nitrosamines as a part of their own, a single impurity control strategy, readiness. Every chapter follows the same path — impurity source → governing text → version and status → force in the jurisdiction → limit and its origin → company decision → document in which it is recorded → evidence — and closes with the decisions it produces.
The toolkit
17 editable tools per edition: 10 Excel workbooks and 7 Word documents, each with an instructions section stating purpose, source chapters, who completes it and who approves it. PDEs, TTC, LTL, AIs and CPCA categories sit in protected reference sheets, row by row with source, table and label; every Excel tool has a “Check” sheet that recalculates the numerical examples in the sources.
Lifetime updates
Nitrosamines are the moving topic: the CDER AI page and EMA Appendix 1 change without notice. And some dates are already set: ICH Assembly in Prague, 14–18/11/2026; Ph. Eur. Issue 13.1 applicable from 01/01/2027; ICH Q3E in draft, with Step 4 planned for mid-2027; the ICH M7 addendum on nitrosamines in development, with Step 4 planned for March 2030. When the texts change you receive the revised guide and toolkit at no extra cost.
€129, and a snapshot dated 25 September 2026
This edition is rewritten from scratch on the official sources read as of 25 September 2026, including FDA's document on the LTL adjustment for nitrosamines of 24/09/2026. Every document cited carries a status label; the register holds 116 sources with URL and access date, and the 68 decisions the guide leaves to the company are tracked with who decides and where each is recorded.
The price is €129.00. Second edition, September 2026, version 2.0, with the regulatory verification cut-off at 25 September 2026: 227 pages in the English edition, 243 in the Italian, 24 chapters, 6 appendices and 17 editable tools. If you bought the first edition, you receive this one at no extra cost.
The 17 tools in the toolkit
Ten Excel and seven Word, 17 files per edition. No operational value is preset. Periodic testing frequency, batches beyond what the source states, purge factors, (Q)SAR systems, internal alert thresholds, gap assessment weightings: they are “to be defined” placeholders, each with its decision code. PDEs, TTC, LTL, AIs and CPCA categories come from the official sources, with document and table alongside. Example rows concern Arvena Pharma, a fictitious company, and are marked EXAMPLE.
EXCEL01 · Jurisdiction Applicability Matrix
What applies, where, since when and with what force: Q3D, M7, nitrosamines and the Q3 series for the EU, US, UK, Japan, Canada and Switzerland. Statuses verified as of 25/09/2026, relevance by product and a verification log with the date of the last check.
EXCEL02 · Q3D Risk Assessment Workbook
The three Q3D steps for a product: components with mass and data per element, the contribution of each, percentage of the PDE, comparison with the 30% threshold and control plan. It does not derive PDEs for routes Q3D does not cover.
EXCEL03 · Q3D Options Calculator: Option 1, 2a, 2b, 3 and the cutaneous route
From PDEs to permitted concentrations with the equations of Q3D(R2) Section 7 and Appendix 5: volume for parenterals, cutaneous limit with the CTCL for nickel and cobalt. It calculates; the choice of Option stays with the company.
EXCEL04 · M7 Impurity Register: actual and potential
From each impurity to its M7 class, with the evidence trail: origin, database searches, two (Q)SARs, expert review, Ames, proposed and final class. No software named: the final class is the toxicologist's decision.
EXCEL05 · M7 Limits Calculator
From class and duration to the individual and total limit: M7(R2) Table 2 and Table 3, Addendum compounds, limits in µg/day and in ppm at the maximum daily dose. N-nitrosamines stay out: they have calculators of their own.
EXCEL06 · M7 control options and purge register
Options 1–4 per impurity, with the outcome of the M7(R2) Section 8.1 and Q&A 8.1–8.5 criteria. Purge factors are chosen by the company: no literature value is preloaded.
EXCEL07 · Nitrosamine risk evaluation
Risk evaluation per product on the EMA Q&A 4 factors — drug substance, nitrites in excipients, process, water, packaging — with potential nitrosamines, outcome and the need for confirmatory testing by jurisdiction.
EXCEL08 · CPCA calculator
From the EMA Appendix 2 flowchart to score, category and AI for the EU, Health Canada and FDA, with the ppm limit. Category 1 is 18 ng/day in the EU and Canada, 26.5 ng/day in the US; a published AI prevails over the CPCA.
EXCEL09 · Nitrosamine AI calculator
Limits by jurisdiction, multiple nitrosamines, FDA LTL, EU interim limit during CAPA, 10% and 30% thresholds, required LoQ and number of batches. AIs are entered with the source version: no full EMA, FDA or Health Canada table is embedded.
EXCEL10 · Impurity system gap assessment with dashboard
The impurity system against requirements and guidelines, with the source of every row; gaps, actions, CAPA and justified deviations are kept apart. No requirement drawn from draft texts, no preset weightings.
WORD11 · SOP Integrated impurity risk assessment and lifecycle
One procedure for Q3D, M7 and nitrosamines, from scope to monitoring: RACI, decision tree, checklists and change-control matrix. No variation procedure, no preset internal timelines.
WORD12 · Q3D Risk Assessment Report Template
The Q3D report per product, fed by tools 02 and 03, with outcome and control strategy. PDEs only from Tables A.2.1 and A.5.1; no “total heavy metals” test.
WORD13 · M7 Assessment Report Template with (Q)SAR Expert Review
The M7 report per drug substance: classes, limits, control options and statements for the dossier, with the expert review of the two (Q)SARs. A negative Ames test on the impurity leads to Class 5, never to Class 4.
WORD14 · Nitrosamine Risk Evaluation Report Template
Risk evaluation and confirmatory testing per product, with AI by jurisdiction, decision and actions. No new FDA NDSRI deadline, no LTL for the EU.
WORD15 · Supplier Impurity Questionnaire: API, Excipients, Packaging
The Q3D, M7 and nitrosamine data to request from drug substance, excipient and packaging suppliers, with methods and notification commitments, signed. No preset acceptance threshold.
WORD16 · Impurity Control Strategy Summary Template for the CTD
A single table for the three impurity families and the text for the QOS and Module 3, with the index of the impurity control file. Only CTD sections specified by the sources.
WORD17 · Impurity Inspection and Assessment Preparation Kit
The Chapter 24 questions with expected evidence and red flags, the evidence index, the mock inspection, minutes and sign-off. Questions built for teaching: no real findings.
You can use it from tomorrow morning
| The situation | What you use |
|---|
| The dossier says no element exceeds 30% of the PDE | Chapter 7 + Tools 02 and 12: the control threshold is 30% of the PDE in the drug product, with levels consistently below it; in the absence of other justification, variability is shown with data from 3 production-scale batches or 6 pilot-scale batches |
| A transdermal patch and the cutaneous route | Chapters 6 and 8 + Tool 03: for cutaneous and transcutaneous products Q3D(R2) Appendix 5 applies, cutaneous PDE = parenteral PDE × CMF; for nickel and cobalt the CTCL of 35 µg/g must also be met and, where the two limits differ, the lower applies |
| An Ames-negative impurity ended up in Class 4 | Chapter 11 + Tool 04: an adequately conducted, negative bacterial mutation (Ames) test on the impurity places it in Class 5 (M7(R2) Section 6; Q&A 6.3). Class 4 covers a structural alert shared with the drug substance or with related compounds already tested and non-mutagenic |
| We want to justify Option 4 on purge | Chapter 13 + Tool 06: risk is negligible if predicted purge brings the level below 1% of the TTC or AI; above 1%, measured purge factors must show less than 10% (M7(R2) Q&A 8.1). Batch data below 30% alone are not enough (Q&A 8.5) |
| An NDSRI with no published AI | Chapter 16 + Tools 08 and 09: the CPCA category from EMA Appendix 2. Category 1 is 18 ng/day in the EU and Canada and 26.5 ng/day in the US; categories 2–5 are the same (100, 400, 1,500, 1,500 ng/day). Limit (ppm) = AI (ng/day) / maximum daily dose (mg/day) |
| The project proposes an LTL limit for a nitrosamine | Chapter 16 + Tool 09: in the US, since 24/09/2026, FDA considers that an LTL adjustment may be scientifically supported (80×, 13.3×, 6.67×), to be proposed through a supplement and not applicable to interim limits. In the EU the LTL approach is not used to calculate limits: it is allowed only as an interim limit during CAPA implementation (EMA Q&A 22) |
| Someone quotes “the 1 August 2025 NDSRI deadline” for the EU | Chapters 2 and 14 + Tool 01: in the EU there is no specific NDSRI deadline of 01/08/2025; all “call for review” deadlines have passed and CAPAs must be implemented within 3 years of publication of the AI. The date is FDA's, which announced targeted timelines not published as of 25/09/2026 |
| Can the nitrosamine test come out of the specification? | Chapter 17 + Tool 09: in the EU it may be omitted only if levels are consistently < 10% of the AI-based limit (LoQ ≤ 10%); skip testing per ICH Q6A is acceptable if a single nitrosamine stays consistently < 30% (LoQ ≤ 30%). In the US a specification is not needed if levels are ≤ 10% of the AI, with the root cause understood and the process validated |
| An inspection or assessment is coming | Chapter 24 + Tool 17: four case studies on Arvena Pharma and 24 questions an inspector or assessor may ask, each anchored to the text that makes it legitimate, with expected evidence and red flags |
Why an impurity number without a document does not hold
Three logics, no crossover. The Q3D PDE, the M7 TTC and a nitrosamine AI answer three different questions. The ICH M7(R2) TTC is 1.5 µg/day, corresponding to a theoretical excess lifetime cancer risk of 10⁻⁵; N-nitrosamines belong to the cohort of concern, the TTC does not apply routinely and limits rest on specific AIs. The guide shows, with document and table, where every number comes from and where it applies.
Neither “mandatory” nor “never binding”. In the EU scientific guidelines have no legal force but deviations must be justified; Q3D, a CHMP guideline, becomes legally binding for pharmaceutical preparations through Ph. Eur. general monograph 2619, which refers to chapter 5.20. In the US guidance documents are not binding (21 CFR 10.115) but represent FDA's “current thinking”; <232> applies to drug products with a USP monograph through General Notices 5.60.30.
Nitrosamines move, and the guide says by how much. EMA Q&A Rev.23 of 10/10/2025 with Appendix 1 Rev.13 of 01/06/2026; FDA Revision 2 of September 2024, the AI tables on the CDER page updated 24/09/2026, the LTL document of 24/09/2026. FDA announced a communication on NDSRI timelines which, as of 25/09/2026, has not been published: only the estimated duration of the Table 3 interim limits has been extended, to 01/08/2027. The ICH M7 addendum on N-nitrosamines, the future M7(R3), is in development and has no public draft: Step 4 is planned for March 2030. ICH Q3E is in draft and leaves the safety assessment of elemental leachables to ICH Q3D.
No date, no limit and no code without a source. Nine labels in two families state, at every citation, the status of the document (current, not yet applicable with its date, draft, in development, superseded) and the nature of the statement (requirement, guidance, good practice, GuideGxP elaboration). Verification cut-off 25 September 2026, a register of 116 sources, 68 decisions tracked. No statistics on inspection findings or dossier deficiencies: none is published in the official sources consulted, and the guide says so. No (Q)SAR software names, no numerical purge factors, no IARC classifications.
Inside the guide
Part I — Three families, three limit logics (chs 1–4). How to read the guide, with the nine labels and five reading paths by role; the calendar from 2006 to 2030; legal force and the jurisdiction rule, from Ph. Eur. 2619 → 5.20 to the Art. 5(3) opinion, FDA guidance and the USP; which text governs which impurity, with the boundaries towards Q3E and HBELs.
Part II — ICH Q3D: elemental impurities (chs 5–9). Scope, exclusions and element classes; PDEs, their derivation, routes of administration and what changed with R1 and R2, including Appendix 5 for the cutaneous route; the three-step risk assessment and the control strategy; from PDEs to concentrations with Options 1, 2a, 2b and 3; Q3D in the dossier and across the lifecycle.
Part III — ICH M7: mutagenic impurities (chs 10–13). Scope, actual and potential impurities, clinical development and marketed products; the assessment with databases, two (Q)SAR methodologies, expert review, Ames and Classes 1–5; limits: TTC, LTL, multiple impurities, the Addendum and the cohort of concern; control: Options 1–4, purge, periodic testing, degradation products and documentation.
Part IV — Nitrosamines (chs 14–17). The regulatory framework in the EU, US, Canada, UK, Switzerland and Japan; risk sources and risk evaluation, from nitrites in excipients to water and packaging; the acceptable intake with Appendix 1, CPCA, Enhanced Ames Test, read-across, multiple nitrosamines and LTL; testing, control and actions.
Part V — Integration and governance (chs 18–21). A single impurity control strategy per product, with one file and one change control; the laboratory: methods, limits of quantitation and data; in the CTD, what goes where; texts on the move — Q3E, Q3C(R10), the M7 addendum on nitrosamines, Q6(R1), the EU pharmaceutical reform — and how to monitor them.
Part VI — Readiness and verification (chs 22–24). Recurring errors in six families, each measured against a cited official text; gap assessment of the impurity system; four case studies in the format problem → risk → decision → activities → documentation → evidence → outcome, and 24 questions an inspector or assessor may ask, with expected evidence and red flags.
Plus 6 appendices. The register of 116 sources with URL and access date; the status matrix by jurisdiction; the 68 decisions, each with who decides, on what basis and where it is recorded; the sheets of the 17 tools; the glossary; the reference tables — Q3D(R2) PDEs, M7(R2) classes and limits, Addendum compounds, CPCA — transcribed with source and section.
Read the extract before you buy
The free extract is made of real pages from the book, not a sales summary: 21 pages in the English edition, 21 in the Italian. It contains the regulatory status box with the dates to note, the full table of contents with the real page numbers, the map of which text governs which impurity from Chapter 4, the two equations of Q3D Section 7 with the worked example on Options 1, 2a and 2b from Chapter 8, a complete case study from Chapter 24 — an NDSRI with an AI from the CPCA and two limits, EU and FDA, handled in a single specification — and the sheets of the 17 tools.
Specifications
| Format | A4 PDF — 227 pages (ENG edition) · 243 pages (ITA edition) |
| Edition | Second edition · September 2026 · version 2.0. Rewritten from scratch; supersedes the first edition, sold as “Safety Guidelines ICH S”. |
| Structure | 24 chapters in six parts + 6 appendices |
| Scope | ICH Q3D(R2) and elemental impurities; ICH M7(R2) with its Addendum and Q&As and mutagenic impurities; N-nitrosamines and NDSRIs; ICH Q3A, Q3B and Q3C as the framework. |
| Out of scope | ICH S series and general toxicology; extractables and leachables (ICH Q3E) and E&L studies; HBELs and cleaning limits (Cleaning Validation guide); pharmacopoeial texts as such; method validation (ICH Q guide); CTD structure (ICH M guide); variations and supplements (Regulatory Affairs guide). |
| Jurisdictions covered | European Union, United States, United Kingdom, Japan, Canada and Switzerland |
| Toolkit | 17 editable tools per edition: 10 Excel workbooks and 7 Word documents |
| Languages | The guide and the toolkit exist as an English edition and as an Italian edition, identical in structure: choose the ENG - English or the ITA - Italiano variant. |
| Sources | Register of 116 official sources, with body, title, code, version, URL and access date |
| Decisions | 68 tracked decisions: what is decided, who decides, on what basis, where it is recorded |
| Regulatory cut-off | 25 September 2026 |
| Free preview | 21 pages (ENG edition) · 21 pages (ITA edition) |
| Price | €129.00 |
| Delivery and licence | Instant download after purchase. Individual use, internal to the purchasing company. Digital product: nothing is shipped. |
Who it is for. QA and QPs, Regulatory Affairs and CMC, process chemists, analytical laboratories, toxicologists, supply chain and supplier qualification, consultants. It is written for people who sign a Q3D risk assessment, an M7 assessment or a nitrosamine risk evaluation, or have to defend one in front of an assessor or an inspector, and need to know which table every number comes from, in which version and where it applies.
Who it is not for. It does not cover the ICH S series or general toxicology. It is not the extractables and leachables guide, nor the Cleaning Validation guide for HBELs, nor the pharmacopoeias guide. It does not reproduce the text of the guidelines, which should be kept at hand. And it is not legal or toxicological advice: derived values, such as a PDE for a route Q3D does not cover or an AI calculated from a TD50, are decisions for a qualified toxicologist.
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GuideGxP guides do not replace official regulations (ICH, European Commission, EMA, EDQM, FDA, USP, MHLW/PMDA, Health Canada, Swissmedic, MHRA): they are operational support tools, and users remain responsible for applying the regulations in force correctly in their own company context. Keep the official texts of ICH Q3D(R2), ICH M7(R2) and the nitrosamine Q&As and guidance at hand while reading: this guide does not replace them and is not legal or toxicological advice. The regulatory status described is the one verified as of 25/09/2026: the CDER nitrosamine AI page and EMA Appendix 1 change without notice and must be re-checked before each use, and the status of draft texts and texts in development must be re-verified after the ICH Assembly in Prague (14–18/11/2026). ICH guidelines have no legal force of their own: binding force comes from regional implementation, which this guide states jurisdiction by jurisdiction. Digital product: nothing is shipped.
