Hi Nitrosamine exchange community,
I have recently came across to one very interesting paper around the mutagenicity and genotoxicity of N-nitroso-propanolol (NNP) with various methodologies performed by the FDA.
In summary, against “some” odds NNP is positive for bacterial mutation in the Ames test, damages DNA, induces MN and is mutagenic in human cells.
Revisiting the mutagenicity and genotoxicity of N-nitroso propranolol in bacterial and human in vitro assays - ScienceDirect
With this results I would say the “lol” nitrosamines would maybe get more complex to de-risk with just “in-vitro” and how for example this corresponds to EFPIA position for beta-blockers.