Any saw mill, planing mill, shingle mill or other woodworking plant, or plant manufacturing wood products, operating in or near forest land, and burning refuse wood material outside of and/or adjacent to such mill or plant, shall enclose the area where such refuse is burned with a fireproof wall at least twelve feet (12′) in height and in diameter at least two feet (2′) greater than the longest refuse or wood material so burned by such mill or plant to prevent the escape or spread of fire therefrom; provided, however, that such mills or plants having adequately constructed and properly maintained burners, or those whose burners of any description are not so located that fire does or can escape or spread therefrom and endanger the lives and/or property of others, shall be exempt from the provisions of this section; and provided, further, that the requirements of this section shall constitute the minimum requirements for public safety, and that nothing herein contained shall be construed to prevent the operators of such mill or plant from being required to increase such protection to make the same adequate to the requirements of public safety; and provided, further, that the preceding proviso shall not be construed to require the use of a hooded burner or permanent structure.