Index-based approach

VTT PUBLICATIONS 384 Inherent safety in process plant design. An index-based approach Anna-Mari Heikkila... 

Heikkila AM. Inherent safety in process plant design an index-based approach. Espoo, Finland VTT Pubhcations 384, Technical Research Centre of Finland 1999. 

Heikkila, A.-M., Inherent safety in process plant design—an index-based approach, Ph.D. thesis, VTT Automation, Espoo, Finland, 1999. 

Heikkila, A-M. 1999. Inherent Safety in Process Plant Design. An Index-Based Approach. VTT Publications, Espoo, 384. 

Harvey, O.R., Kuo, L.-J., Zimmerman, A.R., Louchouam, P., Amonette, J.E., Herbert, B.E., 2012. An index-based approach to assessing recalcitrance and soil carbon sequestration potential of engineered black carbons (biochars). Environmental Science Technology 46 (3), 1415-1421. http //dx.doi.org/10.1021/es2040398. 

To assess tlie overall potential for noncarcinogenic effects posed by more dian one chemical, a liazard index (HI) approach has been developed based on EPA s Guidelines for Healdi Risk Assessment of Chemical Mixtures. This approach assumes that simultaneous subtlu eshold exposures to several chemicals could result in an adverse healtli effect. It also assumes tliat tlie magnitude of the adverse effect will be proportional to tlie sum of the ratios of the subtlireshold exposures to acceptable exposures. The non cancer hazard index is equal to tlie sum of the hazard quotients, as described below, where E and tlie RfD represent the same exposure period (e.g., subclironic, clironic, or shorter-term). 

Pharmaceutical cGMPs for the 21st century A risk based approach. US Food and Drug Administration, www.fda.gov/cder/gmp/index.htm... 

Coonradt and coworkers (13) use an empirical hydrogenation activity index based on the aromatle-naphthene ratio In the hydrocracked product. This approach does not provide an Independent measure of catalytic properties. However, It has the advantage that activities are measured under actual hydrocracking conditions and changes in catalytic properties with catalytic aging can be observed. 

More simply Pichon et al. [149] detected the core of S. ambofaciens et P. roqueforti pellets by series of openings. The hairiness of annular zones, as well as the own of clumps was characterized by a complexity index based on the number of holes and the perimeter of the pellet and its holes. The openings approach was also used by Tamura et al. [106] for pellet core detection, but their classification between filament and clumps is based on A/P2. The classification of S. virginiae morphology by Yang et al. [150] into three classes relies exclusively on the Oval Major Axis (OMA) defined by ... 

Component-based approach. This is an option if the mixture composition can be determined, for example, by means of chemical analysis, and if a mixture model is available that can predict the mixture effects. The mixture model can either be simple, for example, summation of PEC/PNEC ratios over all compounds into a hazard index (HI) moderately complex, for... 

The logic and consequences of such an approach are discussed, with background definitions and terminology as a starting point. Close attention is paid to the concept of measurement uncertainty as providing a single-number index of accuracy inherent in the procedure. The appropriateness of the uncertainty-based approach to analytical measurement is stressed in view of specific inaccuracy sources such as sampling and matrix effects. And methods for their evaluation are outlined. The question of a clear criterion for analytical procedure validation is also addressed from the standpoint of the quality requirement which measurement results need to meet as an end-product. 

An index based on the sum or average of bioassay end-points is the simplest to devise. In some instances it may be desirable to combine tests of acute lethality with sublethal tests in order to include a spectrum of organisms and/or responses. Indices are easier to construct if toxicity end-points are first translated into toxic units. The numerical values then can be summed like the chemical properties of a sample. An alternative would be to classify results on an ordinal scale (e.g. 0-10) based on the observed severity of effect. The approach is more subjective, but at least it incorporates expert judgement that should enter the assessment of data at some point. A ranking scale allows any kind of environmental measurement to be included in the index. 

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