Operator exposure filters

Improper disposal of filter media may result in operator exposure. 

Ever-increasing environmental concerns may make it necessary to evaluate the existing process to reduce emissions, operator exposure, limit waste disposal of filter aid, or reduce wash quantities requiring solvent recovery or wash treatment. Breakdown of an old piece of equipment often provides the opportunity and justification to improve plant conditions. New grass roots designs may have the tendency to revert to industry standards. This is also the opportunity to improve conditions or substantiate the current equipment of choice. 

The vessel can also be jacketed for heating and/or cooling and the agitator blade heated. This design can now be a reactor in combination with a filter-dryer or alone as a filter-dryer (Fig. 10) (see also Chapter 17). This is particularly advantageous for dedicated production of toxic materials requiring an enclosed system. Operator exposure and product handling are minimized. 

Many filters in chemical process units are either changed very rarely or are back-flushed automatically so there is hardly any exposure. Some filters, however, require frequent manual changing or cleaning and significant exposure may occur unless operators foUow the proper procedure. The filter container should be drained of any toxic material and then flushed and purged as needed so that when it is opened there is only minimal exposure. Zero exposure is difficult to achieve in situations where a disposable paper filter cartridge may retain and slowly release a material that cannot be removed by multiple flushes and purges. 

All data recorded in the data base have been acquired from plant records. Statistical reductions of data for generation of reports or specific end use are available. Data are currently collected from four operating plants (eight units). Time clocks have been installed on components, to record actual exposure time. Event data are available on a broad variety of safety and commercial grade components including pumps, valves, transformers, diesels, filters, tanks (vessels), and heat exchangers. 

One of the unique advantages of renal cell culture rests in making possible the study of the directional aspects of drug exposure and cellular injury that operate in vivo. The technology to grow renal epithelial cells on filter inserts for this purpose has recently been made available (Figure 17.4). This potential provides the opportunity to study compounds that interact or accumulate within the renal tubular epithelium in vivo via tubular reabsorption from the luminal surface or extraction... 

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