EB Green is a type of heavy duty tape used by the UNSC. It is extremely resilient, and emerald green in color. During the Battle of Reach, Fredric-104 used it to secure a M41 Rocket Launcher into the hull of a Banshee flier. It was also used by the Spartans to tape gear such as magazines on their armor.
EB Green is quite likely to be Duct Tape which would follow the US Submarine Fleet's practice of calling Duct Tape EB Green.