Wood waste means untreated wood and untreated wood products, including tree stumps (whole or chipped), trees, tree limbs (whole or chipped), bark, sawdust, chips, scraps, slabs, millings, and shavings. Wood waste does not include:
(1) Grass, grass clippings, bushes, shrubs, and clippings from bushes and shrubs from residential, commercial/retail, institutional, or industrial sources as part of maintaining yards or other private or public lands;
(2) Construction, renovation, or demolition wastes; and
(3) Clean lumber.
40 CFR § 60.2265
Terms used but not defined in this subpart are defined in the Clean Air Act and subpart A (General Provisions) of this part.