SPRINGFIELD, Ore. -- A PeaceHealth urgent care clinic is temporarily closed after a mysterious odor made some workers sick.

An employee at the Gateway facility said the problem has occurred repeatedly over the last eight to nine months. The employee describes it as a waxy, chemical smell.

Workers have complained about headaches and nausea. During that period, the clinic has closed and reopened at least three times.

The employee said they've tried to improve ventilation and have added new sensors. At this time, it's not known what's causing the odor and why people have been sickened by it.

PeaceHealth confirmed the problem, saying they are working with investigators to solve the issue.

"PeaceHealth acted swiftly to temporarily close the Gateway Urgent Care clinic after caregivers reported an unusual odor," a spokesperson said. "We have been working closely with SAIF Corp. experts to test the building's equipment and air quality. That testing is ongoing."

During the closure, the spokesperson said patients can receive care at urgent care locations on West 11th Avenue and at the Valley River Center. 

Businesses in the same building as the Gateway urgent care facility said they have not been impacted and have had crews come out to check.