Local exhaust ventilation hoods and points are required for many operations to ensure reduction of airborne concentrations of contaminants that could pose risk to employees. Hoods include, for example, laboratory fume hoods, soldering bench hoods, extractor arms, gloveboxes, and other exhausted equipment enclosures that perform a safety or health function.
EHS conducts surveys and calibrations on a schedule that depends on use and type of the hood or ventilation system. The results of all calibration, certification and other checks are recorded in an EHS Ventilation database. Additionally, most systems have stickers on them that indicate when the last check was performed.
EHS establishes minimum standards of performance for each hood or system based upon code requirements, nationally recognized standards, and good professional judgment. The performance standard for each hood is listed in the computerized record for that hood. It is the responsibility of the responsible line manager to ensure that a deficient hood is fixed, and to use the hood within its safety limits until it is fixed.
New local exhaust ventilation systems and hoods must meet the requirements of Building and Fire Codes and industry standards, and each hood must have a monitor that quantitatively displays the hood’s performance to the hood user.
Also refer to PUB-3000, Chapter 41 Ventilation, Hoods, and HEPA Filters.
HEPA Filter Testing
High-efficiency particulate air (HEPA) filters may be used to filter hazardous chemical, biological, or radioactive particles from air streams with an efficiency of 99.97 percent. HEPA filters used for safety at Berkeley Lab can be found in vacuum cleaners used to clean up dust and debris that contain asbestos, lead, or other particulates; biological safety cabinets in which biohazardous materials are handled; and in-place ventilation exhaust systems connected to lab hoods and glove boxes where radionuclides are used. LBNL tests HEPA filters to determine whether their particle removal efficiency has been maintained.
Please refer to PUB-3000 Chapter 4.6, regarding ventilation and HEPA filters