2,728. Not Everything Can Be Prohibited With a Vow
Hilchos Nedarim 1:8
Counter to the previous halacha, if a person says: “This produce is to me...” or “Species X is to me...,” “What I eat with person Y is to me pork,” or “…idolatrous,” or “…neveila and treifa,” etc., these things remain permitted and there is no vow. This is because a person doesn’t have the ability to make something that isn’t actually pork, etc. become like pork, etc.
Hilchos Nedarim 1:9
The general rule when one wants to make permitted things considered like prohibited things is that if one can prohibit such a thing with a vow, then it’s prohibited; if one can’t prohibit such a thing with a vow, then it remains permitted.