Exhaust hood glove boxes

Plutonium solutions that have a low activity (<3.7 x 10 Bq (1 mCi) or 10 mg of Pu) and that do not produce aerosols can be handled safely by a trained radiochemist in a laboratory fume hood with face velocity 125—150 linear feet per minute (38—45 m/min). Larger amounts of solutions, solutions that may produce aerosols, and plutonium compounds that are not air-sensitive are handled in glove boxes that ate maintained at a slight negative pressure, ca 0.1 kPa (0.001 atm, more precisely measured as 1.0—1.2 cm (0.35—0.50 in.) differential pressure on a water column) with respect to the surrounding laboratory pressure (176,179—181). This air is exhausted through high efficiency particulate (HEPA) filters. 

One w ay to minimize or eliminate exposure to contaminants is to have a completely closed box wdth a glass or plastic panel to look through and gloves mounted in one or more walls. This type of local exhaust hood makes it possible to have a completely shielded workplace available nearly anyw here. 

In all laboratory experiments and procedures, it is important that hazards be controlled or managed primarily by engineering measnres, snch as a laboratory hood, local exhaust ventilation, or a glove box. Ventilated enclosures can often be used for weighing chemicals. Best practices also include having a laboratory under negative pressure with respect to the adjacent hallway so that hazardous chemical vapors are kept in the laboratory. In same cases, such as with the use of radioactive materials, personal hand, foot, or full-body monitors may be needed to control the spread of material into areas outside controlled laboratory facilities. 

The characterization of the engineering controls that are relevant to the exposure to be monitored (i.e., local exhaust hoods, enclosures, glove boxes, lab hoods, HEPA vacuums, etc.)... 

Use a glove bag or dry box inside a fume hood to work with curie levels of tritium. Pass exhaust air from the glove bag or dry box through a prefilter and tritium trap (e.g., a water bubbler). The tritium concentration exhausted through the fume hood should not exceed 0.2 microcuries per cubic meter. 

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