All 10 people hospitalized following exposure to toxic fumes at downtown Salt Lake City's Temple Square had been released and returned home as of Friday.
"All were evaluated and released," said Ruth Todd, a spokeswoman for The Church of Jesus Christ of Latter-day Saints.
The 10 complained of nausea, coughing and difficulty breathing after inhaling the thionyl chloride resulting from an accidental mixture of chlorine and sulfur by a janitor at the square's South Visitors Center, just before noon Thursday.
About 50 people were evacuated from the building and evaluated by paramedics at the scene. Ten people, including the janitor, were taken to the hospital for further treatment.
The South Visitors Center was reopened by 2:30 p.m. Thursday.