Passive charcoal badges

The sorbent tube is placed near the worker s breathing zone, and the outlet of the tube is attached to a calibrated personal sampling pump. A known volume of air is drawn through the tube. Alternatively, several passive charcoal badges are currently commercially available. No sampling pump is required for these devices,... 

Health and Safety. Remover formulas that are nonflammable may be used in any area that provides adequate ventilation. Most manufacturers recommend a use environment of 50—100 parts per million (ppm) time weighted average (TWA). The environment can be monitored with passive detection badges or by active air sampling and charcoal absorption tube analysis. The vapor of methylene chloride produces hydrogen chloride and phosgene gas when burned. Methylene chloride-type removers should not be used in the presence of an open flame or other heat sources such as kerosene heaters (8). 

Advantages and disadvantages of thermal desorption are listed in Table 9.3. (Charcoal badges are also available which require no pump these are termed passive samplers .) Instruments are also available to give direct readout of atmospheric levels of pollutant. 

B. Passive Monitors—Ethylene oxide diffuses into the monitor and is collected in the sampling media. The DuPont Pro-Tek badge collects EtO in an absorbing solution, which is analyzed colorimetrically to determine the amount of EtO present. The 3M 350 badge collects the EtO on chemically treated charcoal. Other passive monitors are currently being developed and tested. Both 3M and DuPont have submitted data indicating their dosimeters meet the precision and accuracy requirements of the proposed ethylene oxide standard. Both presented laboratory validation data to 0.2 ppm (Exs. 11-65, 4-20, 108, 109, 130). 

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