Basic Documentation

Table Of Contents
Laboratory Ventilation Codes and Standards
Siemens Industry, Inc. 136
Topic Requirement(s) Commentary
Components
California OSHA Division of Occupational Health & Safety (DOSH) Subchapter 7.
General Industry Safety Orders, Group 16. Control of Hazardous Substances,
Article 107. Dusts, Fumes, Mists, Vapors and Gases
5143. General Requirements of Mechanical Ventilation Systems
(3) Exhaust ducts which convey dusts, fumes, and mists shall be provided with
inspection or clean-out doors at intervals not to exceed 12 feet of horizontal running
length for ducts up to 12 inches in diameter, but the distance may be greater for larger
ducts. A clean-out door or doors shall be provided for servicing the fan and, where
necessary, a drain shall be provided. (Note: Also refer to 5154.1 below.)
(2) The air exhausted from blast-cleaning equipment, grinding, buffing, polishing
equipment and all other equipment requiring exhausting of dust or particulate shall be
discharged through dust-collecting equipment. Dust and refuse discharged from an
exhaust system shall be disposed of in such a manner that it will not result in harmful
exposure to employees.
5154.1. Ventilation Requirements for Laboratory-Type Hood Operations.
(5) Where emissions from the exhaust stack are likely to cause harmful exposure to
employees, an effective air cleaning system shall be provided. Where virulent
pathogens are likely to be released in the hood, incinerators or equally effective means
of disposal shall be provided in the exhaust system to prevent employee exposure.
5154.1. Ventilation Requirements for Laboratory-Type Hood Operations:
Inspection doors or clean-out doors in exhaust ducts…do not apply to laboratory-type
hood operations (or biological safety cabinets).
(6) Blowers exhausting laboratory-type hoods in which hazardous substances are used
shall be mounted outside the building or in service rooms outside the working area. For
hoods with single, independent exhaust systems, blowers may be mounted inside the
building provided that corrosion-resistant, sealed-joint duct-work is used.
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