Austenitic stainless steels (SS), utilized extensively in coastal environments due to their enhanced corrosion resistance, are susceptible to localized corrosion and stress corrosion cracking (SCC) when exposed to chloride environments and sufficient stresses. One potential scenario under which SCC may pose a concern is the storage and eventual transport of spent nuclear fuel (SNF) in SS canisters. The SS canisters are stored in many locations across the United States and may be subjected to corrosion from brines formed by deliquescence of salt aerosols of varying compositions. Recently, the compositions of salts collected from the surface of SNF interim storage canisters at four different storage sites have been evaluated; these represent both coastal and inland sites, and widely differing compositions. The observed salt chemistries vary from laboratory salts commonly used in corrosion testing (i.e., NaCl, MgCl2, and artificial seawater). Herein, we evaluate the relative corrosivity of the brines through polarization scans, exposure tests, and modeling efforts. The results of this study are discussed in terms of potential canister degradation and improved methods to determine the corrosivity of field-relevant environments. SNL is managed and operated by NTESS under DOE NNSA contract DE-NA0003525. This document is SAND2023-02443C.