43 Pa. Stat. § 301
It shall be the duty of any corporation, manufacturing establishment or colliery, to retain from and out of the wages or earnings of any person by them employed, on his written order, any contribution or voluntary subscription by such person, made in monthly or other payments, for the support of any hospital or other charitable institution, and the sum so retained to pay over upon demand to such hospital or other charitable institution; and any payment so made shall be as valid as if paid to the person by whom said wages or earnings were earned: Provided, That the hospital or charitable institution claiming the same shall give notice in writing at least ten days before the time for the payment of said wages or earnings to such corporation, manufacturing establishment or colliery, of the name or names of the person or persons by them employed, who have subscribed to the support of such hospital or charitable institution, and the amount by them severally subscribed, and when or how often payable, and how long to continue, and file said subscription with said corporation, manufacturing establishment or colliery.
43 P.S. § 301