Imam Sideeq Hassan Khan mentioned a beautiful point when refuting those who say that everything that is prohibited is Impure.
“If it was that the mere prohibition of something necessitates its impurity, then similar to the statement of Allah Ta’alaa:
حُرِّمَتْ عَلَيْكُمْ أُمَّهَاتُكُمْ
Prohibited upon you are your mothers
Until the end of the verse,
(Then similar to it) would be a proof upon the impurity of the aforementioned females in the verse!!”
[Ar Rawdatun Nadiyaa 1/80]
Thus alcohol, dead meat, and blood aren’t impure due to the fact that they are prohibited to consume.
Majid Jawed Al-Afghanee