Chemical Hygiene Plan - Queensborough Community College ...

8) Connect suction or aspirator flasks to an overflow collection flask that contains a
disinfectant (the aspirated materials can then be discarded down the sanitary sewer).
Couple the flasks to an inline hydrophobic or HEPA filter designed to protect the vacuum
system.
9) When the work is completed, remove all items within the cabinet. Do not use the interior
of the BSC as a storage area since stray organisms may become “trapped” and
contaminate the cabinet. Clean all the interior surfaces of the cabinet with a suitable
disinfectant. Let the blowers operate for at least five minutes with no activity inside the
cabinet, to purge the BSC of contaminants.
10) Investigators should remove their gowns and gloves and thoroughly wash their hands
with soap and water before exiting the laboratory.
9.8 Use of Ultraviolet Lights in the BSC
Ultraviolet lights are a common accessory of many BSCs. These lamps are regarded as biocidal
devices “protecting” the operator from exposure to infectious agents, and experimental materials
from contamination. However, the actual effectiveness of UV light in providing this “sterile”
environment is unclear. Additionally, there are potential occupational hazards that carry
significant risks (e.g., serious eye and skin injury) associated with the use and misuse of these
lamps. Ultraviolet lamps must be periodically tested to ensure that the energy output is adequate
to kill microorganisms. The radiation output should be at least 40 microwatts/cm 2 at 254 nm
when measured with a UV flux meter placed in the center of the work surface. Dust that
accumulates on the surface of the lamps (UV light is unable to penetrate through dust or other
materials), can affect the output performance of the lamps. Microorganisms adhering to floating
dust particles or other fixed objects are also “protected” and unaffected by UV illumination.
The effective life spans of the lamps are relatively short and the bulbs are expensive to replace.
However, ultraviolet damage to the eyes and skin can occur well after the output of the lamps has
dropped below the biocidal level. As a result, EHS does not recommend the use of UV lights to
maintain a clean working environment. Instead, a more effective strategy to reduce or eliminate
contamination utilizes well-practiced microbiological procedures, good aseptic techniques,
operational procedures as outlined in this manual, and thorough decontamination procedures
before and after BSC use.
9.4 Glove Boxes
Glove boxes (or glove boxes) are sealed enclosures designed to protect the user, the process or
both. They are usually equipped with at least one pair of gloves attached to the enclosure. The
user manipulates the materials inside using the gloves. Typically, a glove box has an
antechamber that is used to take materials in and out of the box.
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