Minn. Stat. § 325F.28
No person shall remake or renovate any article of bedding unless all the material to be used in such remade or renovated bedding shall first be thoroughly sterilized and disinfected by the methods set out herein, or by any other approved sterilization method:
(3) Formaldehyde and sulphur concurrently in a moist atmosphere for a period of not less than ten hours. Formaldehyde gas shall be generated from the use of one pint of formaldehyde solution, 37 percent to each 1,000 cubic feet of air space, or through the use of any of the high class commercial fumigators which generate an equivalent quantity of gas. Sulphur shall be from the burning of three pounds of sulphur for each 1,000 cubic feet of air space. The moist atmosphere shall be produced by thorough sprinkling of the floor of the room with warm water just prior to the process of disinfection.
The room shall be provided with a separate air inlet and also an exhaust connection, and shall be equipped with tight dampers or closure gates which can be operated from the outside of the room. Rooms for disinfection of bedding materials shall be made gas or steam tight. Shelving for loose bedding materials shall be of lattice or other open construction.
Solid shelves of a type to prevent passage of gas through the materials shall not be permitted.