Ferrous Sulfate: Industry Analysis The ferrous sulfate , also known as the Green Vetriol or Copperas since the middle ages, essentially provides iron needed by the body. The ferrous sulfate market is booming in places where the population is high and is growing quickly, for instance China, India and U.S.A. Asia is a major stakeholder in the ferrous sulfate market and produces roughly around 80% of ferrous sulfate produced in the world.