Interstate 90 is back open from Post Falls to Liberty after a chemical leak had shut it down for nearly 18 hours.
A tanker semi truck was leaking vapors from a load of Trimethylamine Anhydrous, which is used for agricultural fertilizer, at the Washington Port of Entry just four miles east of Liberty Lake.
Technicians with the HAZMAT team were able to cap that leak Monday morning.
Officials shut down I-90 just before 2:30 p.m. Sunday, causing major traffic headaches for drivers.
A car that was following behind the semi truck in Idaho reported the smell of ammonia. The truck was stopped at a weigh station near Liberty Lake.
Trimethylamine Anhydrous is highly toxic, so a HAZMAT crew from the Spokane Fire Department was called in. Officials say that the substance needs a minimum perimeter of 350 feet around it. Because of that, officials decided to shut down the freeway and evacuate the Port of Entry weigh station.
While it isn't a threat right now, the chemical can can cause serious injuries and is highly flammable, so officials aren't taking any chances.