When it comes to API risk assessment, one needs to consider not just the main reaction steps but also the chemistry involved in the reagents, solvents, and impurities for both Amines and Nitrosating agents sources. Before jumping to conduct confirmatory testing purge calculations can be performed to measure the true risk of nitrosamines forming.
In the post below, Schlingemann et al (@schlinjo1975) clearly utilize these tools and validate their results for the API risk assessment evaluation
Good discussions to help you navigate and answer your question related to water.