Naiffer, the link you provided to the toxplanet CPDB web-site does provide TD50 values, a study data summary, and literature references to their carc studies. And yes this is a static database. The FDA has determined that the CPDB carc studies for NMPA were not robust enough so that a rat TD50 value could be used. Consequently, they defaulted to the TD50 value for NDEA. NDMA is the most widely studied nitrosamine. The Nitrosamine SAR workgroup is developing monographs for NDMA as well as other popular nitrosamines. Hopefully, these will be published later this year.