US FDA: Carcinogenic Potency Categorization Approach for Nitrosamine Impurities
Recommendation

10/11 February 2026
In January 2025, the US FDA has published in its newsroom on the CDER website the article called "Determining Recommended Acceptable Intake Limits for N-nitrosamine Impurities in Pharmaceuticals: Development and Application of the Carcinogenic Potency Categorization Approach". It is structured in the following chapters and passages:
- Background
- Materials and Methods
- Results
A) α-Hydrogen features in the format "n,n" where the lowest number of hydrogens is listed first
B) Deactivating features
C) Activating features - Discussion
- Other resources
The article clearly explains the historical background of developing and establishing the "Carcinogenic Potency Categorization Approach (CPCA)" and provides an overview of deactivating and activating features in a listed order.
The complete article "Determining Recommended Acceptable Intake Limits for N-nitrosamine Impurities in Pharmaceuticals: Development and Application of the Carcinogenic Potency Categorization Approach" can be checked in the newsroom of CDER's website.



