Albert Barnes Commentary Leviticus 11:24-28

"And by these ye shall become unclean: whosoever toucheth the carcass of them shall be unclean until the even; And whosoever beareth [aught] of the carcass of them shall wash his clothes, and be unclean until the even. Every beast which parteth the hoof, and is not clovenfooted, nor cheweth the cud, is unclean unto you: every one that toucheth them shall be unclean. And whatsoever goeth upon its paws, among all beasts that go on all fours, they are unclean unto you: whoso toucheth their carcass shall be unclean until the even. And he that beareth the carcass of them shall wash his clothes, and be unclean until the even: they are unclean unto you." — Leviticus 11:24-28 (ASV)

Unclean - If the due purification was omitted at the time, through negligence or forgetfulness, a sin-offering was required. See Leviticus 5:2.