Updated Wednesday 1:28 p.m. Seven people were hospitalized Tuesday after an acid spill at a dialysis center that shares a building with the Yale School of Nursing.

Around 5:30 a.m., workers at the privately-run dialysis center spilled several gallons of an acid mixture used to clean dialysis equipment, the New Haven Register reported. The workers tried to ventilate the area after the spill, but in doing so, they allowed fumes to spread throughout the building. When other workers and patients arrived later in the morning, several complained of nausea, abdominal pains and throat irritation.

The seven people hospitalized have since been released from local hospitals.