Argonite was a combination of argon and nitrogen. Seventeen parts per million was within safety margins for Deep Space 9's air supply.
In 2373, Julian Bashir told Benjamin Sisko he was concerned with how much argonite was seeping into the station's air supply. (DS9: "Doctor Bashir, I Presume")
Argonite is trademarked and owned by Ginge-Kerr.