SALT LAKE CITY — At least 56 people have been affected by a "significant" spill of sulfur dioxide at Thatcher Chemical Wednesday morning.
The incident was reported just after 9 a.m. at the chemical manufacturing and distribution plant, 1905 W. Fortune Road (1270 South). A rail car with a hose on it that was transporting sulfur dioxide was hit by a second rail car for an unknown reason, causing the hose to start spraying the toxic gas.
Approximately 300 to 400 gallons of the sulfur dioxide spilled from the rail car, according to Salt Lake Fire Division Chief Ryan Mellor. Originally, the fire department reported that about 1,000 gallons had spilled.
Once the chemical hit the ground it created a plume of gas. But officials said the gas dispersed quickly.
The vapors from the chemical, which are significantly heavier than air, went to a retaining pond built for such incidents and some vapors followed the irrigation canal, Mellor said. Most of the people who reported being affected by the sulfur dioxide were located along the canal, Mellor said.
At least two people were transported to local hospitals in unknown conditions for potential exposure, Mellor said. Others were either treated at the scene or drove themselves to the hospital. Most experienced symptoms such as burning throats and breathing problems.
An official at Intermountain Medical Center said eight people were still receiving treatment at the facility Wednesday afternoon, but all should recover fully.
By midmorning Wednesday, the only dangerous levels of the chemical were coming from the retaining pond, Mellor said. Some people along the irrigation canal might feel a slight irritation in their throats if they are downwind or downstream from the spill, he said, but staying indoors would resolve the problem.
By noon, Mellor said, the vapors had dissipated and people at nearby businesses and residents would be able to go outside with no problems.
The Utah Department of Environmental Quality notified residents in the area of 2200 South and 1900 West they should go indoors if they felt burning in their throat or eyes. DEQ officials said they would be conducting "follow up in the coming days to investigate what happened and if any permits were violated."2 comments on this story
The DEQ reported that Thatcher has had no violations in its last five inspections.
However, the company did experience nearly a dozen incidents at the facility between 1990 and 2010, according to DEQ records, including in 1991 when a sulfur dioxide leak forced the evacuation of more than 13,000 people and sent 300 to area hospitals.
Significant accidents also were noted in 2003, when hydrochloric acid forced the evacuation of 100 employees and nearby residents, and in 2004 when a tank containing sodium thiocarbonate exploded.
Contributing: Dan Rascon, Mike Headrick