CMC & ManufacturingLast reviewed April 2026

ICH M7(ICH M7)

The ICH guideline on assessment and control of DNA reactive (mutagenic) impurities in pharmaceuticals to limit potential carcinogenic risk.

Usage Examples

The M7 assessment classified three process impurities as Class 2 requiring specification control below TTC.
Nitrosamine risk assessment followed M7 "cohort of concern" principles with AI limits in nanograms per day.

What is ICH M7?

ICH M7 (2014, revised 2017 as M7(R1)) provides harmonized guidance on identification, evaluation, and control of mutagenic impurities in drug substances and products. The scope includes impurities potentially reactive with DNA that could be carcinogenic if present above acceptable levels. M7 applies a threshold of toxicological concern (TTC) approach: 1.5 μg/day TTC for most drugs, with adjusted limits for short-duration therapy, life-threatening conditions, and specific known mutagens (the "cohort of concern").

The M7 framework: identify potential mutagenic impurities (in silico analysis, literature review, actual or predicted formation), classify (Class 1-5 based on mutagenic potential), control based on class and patient exposure, and document risk assessment. The nitrosamine emergence (2018+) expanded M7 application — nitrosamines are treated as "cohort of concern" with AI limits below standard TTC. M7 assessment is required in Module 3.2.S of the submission.

Regulatory Context

This term appears most often in cmc & manufacturing workflows where submission quality, regulatory evidence, and audit readiness depend on consistent language. It is commonly referenced alongside ICH M7, ICH Q3A, ICH Q3B.

FDAICHHealth Canada

When This Matters

The M7 assessment classified three process impurities as Class 2 requiring specification control below TTC.
Nitrosamine risk assessment followed M7 "cohort of concern" principles with AI limits in nanograms per day.

Common Mistakes

Failing to align CMC change narratives with current CFR/ICH expectations.
Submitting incomplete control strategy documentation.
Separating manufacturing and regulatory review cycles too late in execution.

Related Regulations

ICH M7ICH Q3AICH Q3B

Frequently Asked Questions

1.5 μg/day for most drugs — the dose of an unidentified impurity below which cancer risk is considered negligible. Short-duration therapies (≤1 year) may use higher TTC; life-threatening conditions with limited therapeutic alternatives may accept higher exposure with justification.

Specific classes of high-potency mutagens (aflatoxins, N-nitroso compounds, alkyl-azoxy compounds) with carcinogenic potency substantially higher than standard mutagens. TTC does not apply; individual acceptable intake limits are established per compound.

No. In silico analysis (QSAR predictions from two complementary models) and literature review can satisfy assessment for many theoretical impurities. Confirmatory analytical testing is required when in silico predicts mutagenic potential AND exposure risk is meaningful.