Things Are Back To Normal At The Us Nitrogen Plant In Greeneville After A Nitric Acid Release. It Happened Around 6:30 Last Night. The Leak Was Quickly Contained And No Workers Were Injured. The Hazardous Material Team Spent About Three Hours Testing The Air Quality, And Deemed It Safe For Workers To Return. Officials Don’t Know How Much Nitric Acid Was Released But Described It As A Hazardous Material That Would Put Anyone In Danger Should They Be Impacted By It. Us Nitrogen In Greeneville, Produces Liquid Ammonium Nitrate.