Worland Volunteer Fire Department -07/07/2017 WFD was called to Smet Recycling on HWY 20 North for a report of an unknown type of fire. Upon arrival we found that the fire was a sulfur mound that had been ignited. Despite the beautiful flames, burning sulfur creates a hazardous gas called sulfur dioxide. WFD was able to position apparatus in a safe location and lay in a line to extinguish the fire. We captured the video, while in full PPE and wearing SCBA's during a size up of the situation, as crews were setting up for suppression.** Update / Response to comments and questions: Burning sulfur creates sulfur dioxide (SO2) gas that has a very strong, choking odor. The fire was burning in a “bowl” shaped area, allowing all runoff to be collected in the fire area. A minimal amount of water was used to cool the surface of the sulfur and reduce the temperature below the molten stage. Adding water to an SO2 gas creates sulfurous acid, (not to be confused with sulfuric acid) which can be related to “acid rain”. Apparatus and personnel placement as well as careful monitoring of the weather conditions in relation to smoke and chemical plume is very important. The deposits in rural Washakie County are leftover from the Texas Gulf Sulfur Plant that operated north of Worland in the 1950’s. Much of the sulfur is mixed heavily with soil and is not 100% sulfur concentrate. This is a type of fire that is not common but needs to be addressed and dealt with safely and quickly. Fortunately the WFD has Hazmat Technicians and we have an understanding of this as we deal with H2S and SO2 on a somewhat regular basis.Video recorded by Brandon Yule, Captain, Worland Volunteer Fire Department.