LOWER PROVIDENCE TWP., Pa. (CBS) — Several people were taken to the hospital and approximately 50 homes were evacuated after a strong chemical odor went airborne in a Montgomery County neighborhood Thursday.

The incident happened shortly before 9 a.m. in the area of Clearfield and Woodlyn Avenues in Lower Providence Township.

According to investigators, several residents began complaining of a strong chlorine-type smell.

Officials said four people were taken to the hospital as a precaution after complaining of dizziness.

According to Lower Providence Township officials, the source of the odor was determined to be the ER Joseph Company on Woodlyn Avenue, where the cleaning of a tank caused the chlorine to become airborne. The tank was capped, isolating the source.

Because emergency personnel needed to vent the area, residents in the surrounding area were advised to shelter-in-place for a short period of time. All restrictions were lifted by noon.

All active scene operations ended at 12:45 p.m.

The incident remains under investigation.