Target level environments

It is typical for industrial premises to have, in one space, zones with different target levels. The target levels may be determined for the whole area or locally. Often only a part of the space requires controlling of the indoor environment parameters. In addition to the main controlled zone, there may be one or more local controlled zones with target levels different from those in the main controlled zone. 

Nowadays many companies have adopted a policy of continuous improvement of working conditions. Therefore, it is desirable to create target levels for those who want to pursue more efficient control by applying the best available control technologies. There are also endeavors to create optimal working conditions in order to improve the performance and the innovativeness of a staff, and hence enhance productivity. A series of laboratory and case studies show that employee productivity is higher when the work environment is appropriate for the tasks being done.- Such efforts are typical in the advanced sector of industry. One can say that there is a transition from blue-collar to white-collar work. ... 

The target level procedure was applied to 16 common air contaminants (Table 6.19). These are common contaminants in the industrial environment, and in many cases are the most critical compounds from the viewpoint of need for control measures. The prevailing concentration data as well as the benchmark levels were taken from Nordic databases, mainly the Finnish sources, and described elsewhere.In addition, a general model for assessing target values for other contaminants is presented in the table. 

The previous procedure can be used for assessing target levels for a variety of substances in work rooms with notable contaminant emissions. A different set of target levels has already been proposed for nonoccupied environments. 

ACC member companies are required to establish company-specific goals against which progress is measured toward the common vision of no accidents, injuries, or harm to the environment. An example of one such goal is to limit the annual number of process safety incidents below a target level. 

It is interesting to note the reduction in permissible and planned SO2 emissions of the two commercial ventures, Suncor, Inc. and Syncrude Canada Limited and the proposed Alsands Project. These data are presented in Figure 5 as well as the target SO2 emission level proposed by Alberta Environment. Data are in Long Tons SO2/IOOO barrels of synthetic crude product. The proposed Alsands rate is approaching the target level of Alberta Environment but implementation of new technology will be required to meet these objectives in the future. 

Tier 2 produces site-specific target levels (SSTLs) that are protective of human health and the environment, but utilizes more site-specific data than Tier 1. This level of sophistication should address 70-80% of the sites. This more site-specific assessment involves the assumption of reasonable use exposure assumptions, considers actual beneficial uses of resources, and provides a tool for determining points of compliance. 

Used oil analysis serves as the measurement apparatus for the contamination factor. Start by establishing meaningful target levels for each of the machines, taking into account mechanical sensitivity, application and/or environment severity and the machine s criticality to production, safety, environmental protection and/or other aspects of the mission. Compare the actual performance to targeted performance and report the percentage of the machines that comply with contamination targets (Fig. 8). 

Breakpoint chlorination. Breakpoint chlorination is a historical concept where combined chlorine is reoxidized to hypochlorous acid by the addition of an excess concentration of hypochlorous acid. These are collectively referred to as combined chlorine or combined available (CAC) under the assumption that the chlorine can be re-liberated. The model used for nearly all literature cites the interaction between hypochlorous acid and ammonia. In recreational water the amount of hypochlorous acid used for a breakpoint treatment is normally ten times the concentration of the combined chlorine. However, the reaction between hypochlorous acid and more complex nitrogen compounds is not fully reversible. White (1986) showed that breakpoint water containing a mixture of combined chlorine from organic and simple ammonia failed to display the elassic dip of the breakpoint reaction. These waters displayed a plateau concentration below which no further reduction in combined chlorine occurred. The nitrogen compounds in recreational water are introduced in bather waste and from the environment and contain mostly amino acids, peptides, and proteins with little free ammonia. Practical experience has shown that this method will reduce, but not eliminate, the combined chlorine. If repeated breakpoint treatments fail to reduce the combined chlorine to the target level (0.02 to 0.05 ppm CAC) alternate treatments such as oxidation with a potassium monopersulfate or partial water replacement to dilute the chloramines must be used. 

This theory is based on the assumption that the operator is able to perceive a risk level in the environment that is related to the actual risk level through a delayed feedback. The operator adapts his or her behaviour in such a way that there is a balance between the hazards that the operator is exposed to and what he or she can accept (target level of risk). It follows from this theory that measures to reduce hazards at the workplace will be followed by changed behaviour on the part of the operators such that their perceived level of risk remains the same. The only way to improve safety is to change the operators target risk level. The risk-homeostasis theory was primarily developed for situations where people voluntarily expose themselves to accident risks such as in traffic. We must expect, however, that employees at a workplace also to some extent control the risk that they are exposed to based on their own experiences and preferences. 

Target values for thermal conditions at different design stages must also be considered. One example, for a scenario similar to regular office work, is shown in Table 8.2. The activity level and clothing insulation of the workers must always be taken into consideration when target values are chosen. Different target values other than the ones used in this table could be required, for example, for very cold and very hot and humid environments. 

R. E. Hicks, R. I. Amann, and D. A. Stahl, Dual staining of natural bacterioplankton with 4, 6-diamidino-2-phenylindole and fluorescent oligonucleotide probes targeting kingdom-level 16S rRNA sequences, Appl. Environ. Microbiol. 571 2158 (1992). 

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