The call came in around 2 p.m. at the Jewell Fruit Company warehouse. About 50 people evacuated.
Authorities shut down First Avenue from D Street to I Street for a couple of hours.
Investigators say around a hundred pounds of liquid ammonia leaked from a refrigerator valve. The malfunction sent the ammonia from the roof to the ground.
Haz Mat responded as a precaution, but didn't need to go inside the facility.
"Our initial issue was we didn't know how concentrated it was and it wasn't shut off just yet and that's what we had to get control of," said Capt. Tom Schneider, Yakima Fire spokesperson.
Crews shut off the broken valve. There's no word on the two people taken to the hospital.