B. Blackman was a Human Starfleet officer in the 22nd century.

In 2154, he was listed as an Environmental Systems officer on the dedication plaque of the Columbia NX-02. (ENT: "Affliction", dedication plaque)

In January of 2155, he was listed as an ECLSS officer on directory placards at Starfleet Command's Fleet Operations Center, Sol Sector. His office was located in room #3532. (ENT: "Demons", directories)

This character was only mentioned in writing.
He was named for costume designer Bob Blackman, who worked on Star Trek: The Next Generation, Star Trek: Deep Space Nine, Star Trek: Voyager, and Enterprise, as well as Star Trek Generations.