Mass. Gen. Laws ch. 149, § 121: Nonapplicability of statutes relating to emery and buffing machinery

Section 121. The two preceding sections shall not apply to grinding machines upon which water is used at the point of grinding contact, nor to solid emery wheels used in sawmills or in planing mills or in other woodworking establishments, nor to any emery wheel six inches or less in diameter used in establishments where the principal business is not emery wheel grinding.