All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
If the aforementioned person had a wet dream and ejaculated during sleep, then it is obligatory on him to perform Ghusl (ritual bath), but the semen is pure according to the most preponderant opinion of the scholars, and this is the view that we adopt here in Islamweb. Therefore, neither the hand nor anything else becomes impure by touching semen.
According to the view that the semen is impure, it is only obligatory to wash the hand, or garment, or anything else that you are definitely certain that they have been stained by semen. As for the body or belongings of the person who had a wet dream, that have not been stained by semen, then they remain pure according to the principle, which is the purity of those places and bedding until one is certain that they have become impure.
Ar-Rawdh and its footnote reads:
“If one doubts about the impurity of water, or other pure things such as a garment and a vessel, then he acts according to the principle.” [End of quote]
For more benefit that semen is pure, please refer to Fatwa 428017.
Allah knows best.