Emergency responders say a chlorine incident that prompted dozens of homes to be evacuated in Montgomery County on Thursday morning had been placed under control.

The evacuations occurred after an odor of chlorine was reported at about 8:45 a.m. in the area near Clearfield and Woodlyn avenues in Lower Providence Township, according to township officials.

About 50 homes were evacuated. People were able to take temporary shelter at the Lower Providence Fire Company.

The odor came from MAWA Inc., gas cylinder services business formerly known as the ER Joseph Company, on Woodlyn Avenue.

Chlorine became airborne while a tank was being cleaned, officials said.

The tank was capped and the area was ventilated, the township said.

Four people were taken to an area hospital for evaluation after complaining of dizziness.

Some in neighboring areas, including West Norriton Township, were asked to shelter in place for part of the morning due to the strong chemical odor during ventilation efforts.

The evacuations and shelter-in-place orders were lifted by noon, and emergency crews cleared the scene at 12:45 p.m.

The incident remains under investigation by township officials, the Department of Environmental Protection and the Occupational Safety and Health Administration.