S.C. Code Ann. § 63-17-1410
As used in this section:
(4) "Income" means any periodic form of payment to an individual regardless of source including, but not limited to, wages, salary, commission, bonuses, compensation as an independent contractor, workers' compensation, disability, annuity and retirement benefits, payments made pursuant to a retirement program, interest, and any other payments made by a person or an agency or department of the federal, state, or local government provided the income excludes:
(c) public assistance payments.
Any other state or local laws which limit or exempt income or the amount or percentage of income that can be withheld do not apply.