by Answer: more often than naught.
This one is a fairly broad question, but the answer is almost always, yes. Steamed, flashed and packaged whole, crushed and chopped tomatoes are almost ALWAYS vegan. I haven’t found any brands that have non-vegan additives. Pre-packaged pasta sauces are different. Obviously, you should avoid meat and sausage additives. Some brands put cheese in even their “traditional” or “classic” sauces, like Ragu. Ragu uses romano cheese in almost all of their sauces.
In summary, most of these are going to be vegan. But be careful to check the ingredients for meat, cheese and honey. These are the usual culprits.
Some pre packaged tomato sauces also add red wine to their sauces. As we have no way of knowing whether or not this wine is vegan friendly I think it is pretty safe to assume that it’s not.
As always, you have to read labels! Some are and some are not. Lucky’s Market had a brand with chicken broth in the tomato sauce! Dairy is common too…