Washington Administrative Code › Title 296 - Labor and Industries, Department of › Chapter 296-78 - Safety standards for sawmills and woodworking operations › Section 296-78-71019 - Exhaust systems

Current through Register Vol. 24-14, July 15, 2024
(1) Air
			 requirements in buildings, where persons are habitually employed, must meet the
			 requirements of the general occupational health standard, WAC 296-62-100
			 through 296-62-11013.
(2) Where the
			 natural ventilation is not sufficient to remove dust, fumes or vapors that
			 create or constitute a hazard, additional means of removal must be
			 provided.
(3) All mills containing
			 one or more machines whose operations create dust, shavings, chips or slivers
			 during a period of time equal to or greater than one-fourth of the working day
			 or shift, must be equipped with a collecting system either continuous or
			 automatic in action and of sufficient strength and capacity to thoroughly
			 remove such refuse from the points of operation of the machines and the work
			 areas.
(4) Each woodworking machine
			 that creates dust, shavings, chips, or slivers must be equipped with an exhaust
			 or conveyor system located and adjusted to remove the maximum amount of refuse
			 from the point of operation and immediate vicinity.
(5) Blower, collecting and exhaust systems
			 must be designed, constructed and maintained in accordance with American
			 National Standards Z33.1 - 1961 (for the installation of blower and exhaust
			 systems for dust, stock and vapor removal or conveying) and Z12.20 - 1962
			 (R1969) (code for the prevention of dust explosions in woodworking and wood
			 flour manufacturing plants).
(6)
			 Fans used for ventilating must be of ample capacity, as evidenced by the
			 performance schedules of the manufacturers, and must be guarded when exposed to
			 contact. Hoods, dust conveyors, dust collectors and other accessary equipment
			 must be large enough to insure free intake and discharge.
(7) The outlet or discharge of all
			 ventilating equipment must be arranged so that at no time will the dust,
			 vapors, gases or other air borne impurities discharged, create or constitute a
			 hazard.
(8) Where a hood is used to
			 form a part or all of the guard required on a given machine, it must be
			 constructed of no less than ten U.S. gauge sheet metal, or if of cast iron it
			 must not be less than three-sixteenths inches in thickness.
(9) All exhaust pipes must be of such
			 construction and internal dimensions as to minimize the possibility of
			 clogging. They must be readily accessible for cleaning.
(10) All exhaust pipes must empty into
			 settling or dust chambers which must effectively prevent the dust or refuse
			 from entering any work area. Such settling or dust chambers must be so designed
			 and operated as to reduce to a minimum the danger of fire or dust
			 explosions.
(11) In lieu of a
			 general ventilating system, exhaust or blower units may be installed on the
			 dust or fume producing machine, provided the required protection is secured
			 thereby.
(12) When proper
			 ventilation is not provided, and temporary hazardous conditions are therefore
			 encountered, you must furnish approved respiratory and visual equipment:
			 Provided, however, That the exposure to such hazard must not be for more than
			 two hours duration. Protective measures and equipment must meet the
			 requirements of chapter 296-842 WAC, Respirators.
(13) Provisions for the daily removal of
			 refuse must be made in all operations not required to have an exhaust system,
			 or having refuse too heavy, or bulky, or otherwise unsuitable to be handled by
			 an exhaust system.
Statutory Authority:
				  RCW
				  49.17.010,
				  49.17.040,
				  49.17.050,
				  49.17.060. 07-03-163, §
				  296-78-71019, filed 1/24/07, effective 4/1/07; 05-03-093, § 296-78-71019,
				  filed 1/18/05, effective 3/1/05. Statutory Authority:
				  RCW
				  49.17.010,
				  49.17.040, and
				  49.17.050. 01-11-038, §
				  296-78-71019, filed 5/9/01, effective 9/1/01; 99-10-071, § 296-78-71019,
				  filed 5/4/99, effective 9/1/99. Statutory Authority:
				  RCW
				  49.17.040,
				  49.17.050 and
				  49.17.240. 81-18-029 (Order
				  81-21), § 296-78-71019, filed
				  8/27/81.