For the purposes of sections 178.900 to 178.960 the following words mean:
(1) "Department", the department of elementary and secondary education;
(2) "Disabled persons", a lower range educable or upper range trainable developmentally disabled or other disabled person sixteen years of age or over who has had school training and has a productive work capacity in a sheltered environment adapted to the abilities of persons with a developmental disability but whose limited capabilities make him or her nonemployable in competitive business and industry and unsuited for vocational rehabilitation training;
(3) "Sheltered workshop", an occupation-oriented facility operated by a not-for-profit corporation, which, except for its staff, employs only persons with disabilities and has a minimum enrollment of at least fifteen employable persons with disabilities;
(4) "Staff", employees of a sheltered workshop engaged in management, work procurement, purchasing, supervision, sales, bookkeeping, and secretarial and clerical functions.