How It’s Used Sulfur dioxide (aka sulfurous anhydride, sulfurous oxide) is a colorless gas with a choking or suffocating odor. Its use as a fumigant dates back to ancient Greece. Note this passage from The Odyssey, where Odysseus says: “Bring sulfur, old nurse, that cleanses all pollution, and bring me fire, that I may purify … Continue reading Sulfur Dioxide—and Sulfur Dioxide Monitoring Instrumentation