What makes some types of sashimi safe to eat? How do you know if it is safe to eat? Meaning, how do I know if I go to buy some salmon, that it would be safe to eat raw? I had been buying salmon from Costco and preparing sashimi for myself, until a friend of mine who is a chef, told me that I shouldn't do that unless it is sashimi grade fish. I asked Costco, but they had no idea if their fish is sashimi grade. How can I tell what qualifies to eat raw and safely?