I can give it to you from personal experience.
Having ammonia at >1.0ppm will wipe out your tank, everything. And having >100ppm nitrate will not bother your fish at all, but will cause problems with inverts.
Similarly nitrite at >1.0ppm will wipe out your livestock, while I have seen FO systems that are running great for years with >150ppm nitrate.
Nitrate in SW is not highly toxic, ammonia and nitrite is.