Sawmills, planing mills and other woodworking plants shall be equipped
with refuse-removal systems which will collect and remove sawdust and shavings
as produced; or suitable metal or metal-lined bins provided with normally
closed covers or automatically closing covers shall be installed at or near
such machines, and shavings and sawdust shall be swept up and deposited in
such bins at sufficiently frequent intervals as to keep the premises clean.
The burning of shavings, sawdust and refuse material shall be permitted
only under boilers, in furnaces or in properly constructed incinerators or
refuse burners; provided that these materials may be burned in the open if
surrounded by a metal or other wall at least six feet high and distant at
least 50 feet from any building or storage of lumber. All stacks shall be
provided with suitable spark arresters.