Replied by Rob (Seattle ) on 07/23/2022
Orthopoxvirus is a genus of viruses in the family Poxviridae and subfamily Chordopoxvirinae. Vertebrates, including mammals and humans, and arthropods serve as natural hosts. There are 12 species in this genus. Diseases associated with this genus include smallpox, cowpox, horsepox, camelpox, and monkeypox.
Orthopoxviruses are enveloped with brick-shaped geometries and virion dimensions around 200 nm wide and 250 nm long
BHT is known to inactivate enveloped viruses, do it is a reasonable assumption that it would be beneficial for Smallpox