A possible chemical exposure was reported at 4:45 a.m. and the affected man was brought to the hospital, located at 751 S. Bascom Ave., San Jose fire Capt. Cleo Doss said.
Hospital spokeswoman Joy Alexiou said the man was brought in by ambulance after he had been exposed to the substance. He was not decontaminated before he went into the emergency room.
Out of an abundance of caution, the emergency room was shut down and no patients or ambulances were admitted starting around 8 a.m., Alexiou said.
A hazardous materials team responded around that same time to check the hospital and make sure the area was safe for patients, Doss said.
Just after 9:45 a.m., fire crews said there was no evidence of a hazardous substance in the emergency room and normal hospital operations resumed, Alexiou said.
She said the man who was exposed to the substance is in fair condition and is expected to survive.