(1) Closing. The permanent shutting down of operations at any establishment for any reason other than the employer has filed for bankruptcy in accordance with Federal bankruptcy laws or as the result of an involuntary closing as defined in Section 9-1501(4).

(2) Employer. Any person, corporation or other entity which employs or has employed at any time in the proceeding twelve (12) month period at least fifty individuals and has operated an industrial, commercial or business enterprise in the City of Philadelphia for more than six (6) months prior to the proposed date of closing or relocation, but does not include the Commonwealth of Pennsylvania, the City of Philadelphia or nonprofit corporations.

(3) Establishment. Any factory, plant, office, facility, or other working place of an employer, but does not include a construction site, or other work place intended as a temporary work place.

(4) Involuntary Closing:

(a) Any closing pursuant to a court order; or

(b) Any closing caused by fire, flood, or natural disaster, a national emergency, acts of war, civil disorder, or industrial sabotage.

(5) Relocation. The transfer of all or substantially all of an employer's operation from one establishment to another existing or proposed establishment owned or operated by the employer or parent corporation or subsidiaries thereof, located outside the City of Philadelphia unless such relocation is to an establishment within reasonable commuting distance from the first establishment.