This article is very interesting. Please check it.
The comments were in response to the agency’s request for public input on how it should regulate NDSRIs, to help inform safety assessments. Most of the comments from the pharmaceutical industry, including lobbying groups such as the PhRMA, AAM and CHPA, as well as several individual drugmakers, requested a testing reprieve for at least another six months.
AAM: The number of outstanding scientific questions as well as the state of completion of the work across the industry to date suggest that it is unrealistic to establish a deadline less than a year away to complete all of the work to assess the hazards of nitrosamines in drug products and take appropriate remedial action.
PhRMA: In considering the extension date, it is important to understand that it will take until the end of 2023 for the HESI to complete a body of work related to the Ames test, which is intended to inform the optimal Ames protocol for N-nitrosamine hazard identification. This is expected to be an important element of the risk assessment framework which will be used to set AIs and prioritize NDSRIs for further in vivo testing.
CHPA: Request an extension beyond the current deadline of October 1, 2023.
Many members have submitted proposed AI for NDSRIs and are still waiting on FDA feedback.
I strongly think that ten years is what it will take to resolve this issue fully. Agencies are now understanding how little we know about these and once the pandora’s box has opened, we need to deal with everything that has come out. We need to get the public’s confidence back in medicines, have people believe that they have not been consuming carcinogens in drugs. While the EMA guidance is some help, it is not a solution. It is an emperical calculation based on the already published data. We need real data and for that 10 years is possilby optimum. It was also possibly thought that when one asks for 10 years, they may at least get 5 years. 
