Borren is one of the Aschen assigned to the negotiations between representatives of the Aschen and Earth. While visiting Volia, SG-1 came into contact with the Volians who introduced them to the Aschen, with one of them being Borren.
Borren quickly informed SG-1 about the Aschen Confederation and offered Earth a beneficial relationship with in it. After informing Stargate Command about the Aschen, SG-1 was ordered to continue negotiations with the Aschen, with the negotiations being led by Ambassador Joseph Faxon.
These negotiations were conducted with Aschen ambassador Mollem, assissted by Borren. It was however eventually revealed, that the Aschen might not be the honorable people they seem to be, when Dr. Daniel Jackson and Teal'c find information about the recent past of the Volians and a dubious cure which the Aschen provided to them during a pandemic.
Major Samantha Carter and Faxon eventually trick Borren into revealing that this cure caused sterility, leading Mollem to attempt to launch a Biogenic weapon against Earth. From his reaction it seemed that Borren was unaware of what happened to the volians mostly likely due to his likely lower status as evidenced by the color of his suit.
Mollem on the other hand was fully aware and on realizing that the Aschens plan had been discovered, orders Borren to apprehend the two, and proceeds to try to launch a bio weapon on earth by dialing the Volian gate.
Both Carter and Faxon attempt to escape through the Stargate after being imprisoned into the negotiations room, but when Borren reenters the room, Faxon sacrifices himself to engage Borren, keeping him occupied, and giving Carter the opportunity to escape. What happened to Borren afterwards is unknown. (SG1: "2001").
Note: Aschen fashion consists predominantly of identical grey uniform-like tunics. These uniforms are of varying shades of grey, which appears to denote rank role or status in Aschen society.