I think they should be safe
The crunchy ones are quite popular with cats though,not sure about the soft ones(my mind did a bit of a goof!).
As a bit of a tip for those in the US with Publix stores nearby,they might carry Blue Buffalo products including the Kitty Cravings(not Yums,my brain goofed as mentioned already,in particular these are really cost effective since the bag is 5 oz compared to 2 oz in a pet store which almost costs $3 yet the 5 oz in Publix if you can get that is around $3).
Edit:Accidentally got messed up with products!Sorry,my brain's not focused at the moment
The soft treats(Kitty Yums)might still be safe but I'll double check.I know the crunchy(Cravings I believe)should be safe though which are what I was thinking of earlier!After a double check they should be safe though.
The only major issue I could think of would be gelatin,but in treats(not chews,which would get used daily,hence why Greenies aren't a good idea)it shouldn't be too bad.