Life impact categories

Life Cycle Assessment (LCA) considering the impact category global warming... 

The results within the impact category GWP illustrate the great influence of both, the supply of chemicals (33% batch and 37% Conti wc, resp.) and the energy demand during synthesis (42% batch and 28% Conti wc, resp.) along the whole process chain. The disposal of the chemical refuse as well has a significant impact (23% both, batch and Conti wc). In the case of the worst-case scenario, the influence of the supply of the reaction device amoimts to 10% (assumed hfe time of the micro-structured devices 1 week) decreasing to 3% in Conti Scl (assumed life time of the micro-structured devices 3 month). 

The life cycle impact assessment (LCIA) is used to assess the results of the LCA and evaluate the impact on the environment in the various impact categories. These impact categories include, for example, human health, GWP, energy, water use, eutrophication, ozone depletion, aquatic toxicity, and land use (ISO, 2006b). LCA may focus on one or more impact categories. The results may be normalized, weighted, and aggregated in optional steps of the LCIA for comparison to political objectives, for example. In addition, sensitivity analyses are often conducted over the entire LCA to evaluate the variation in the results due to selected factors. 

The inventory results should be presented in clear form, how much and what substances from the environment enter the system and how much get out. These results serve for subsequent life cycle impact assessment [48], The aim of the life cycle impact assessment is to measurably compare the environmental impacts of product systems and to compare their severity with new quantifiable variables identified as impact category. The impact categories are areas of specific environmental problems such as global warming, climate changes, acidification, eutrophication, ecotoxicity and others. Already in the phase of definition of the LCA study scope, it is necessary to describe what impact category will be applied and which of their environmental mechanisms will serve as a basis for impact assessment [46],... 

The second step and the focus of this chapter was to evaluate the emission load of individual foods from the list of most common foods. There was used the simplified Life Cycle Assessment method in which only the Climate change Impact category was assessed. Detailed description of the LCA methodology is shown in the literature review, the following text describes practical method implementation.Food emission load evaluation using the LCA method... 

The life cycle impact assessment (LCIA) may be restricted to one or a few impact categories, where additives do not contribute much. 

As mentioned above, there are characterization factors for a number of different impact categories, e.g. acidification, eutrophication, climate change, human toxicity and ecotoxicity. However, characterization factors are missing for many additives, especially for human toxicity and ecotoxicity, which makes it difficult to assess the potential impact that a product will cause during its entire life cycle. A major reason that characterization factors are often missing is the lack of data regarding substance properties, such as physical chemical properties and toxicity. 

The aim of the Life Cycle Impact Assessment (LCIA) is to facilitate the interpretation of the results of the inventory analysis. The result of the inventory analysis is an emission profile for each alternative system. In this study the emission profile is the total of all emissions to air, water and soil from the grave-to-cradle chain for the use of cushion vinyl floor covering, including the up chain processes, like electricity production and the down chain processes, like the incineration and landfill of the waste. Such an emission profile may consist of hundreds of emissions and extractions. In LCA impact assessment the total of interventions (emissions, extractions) of a process chain is evaluated in terms of environmental problems (impact categories). 

Figure 2 shows the weighted impact scores of the use of 1 m2 cushion vinyl floor covering, broken down into environmental impact categories and Life Cycle stages. 

Impact, ceramics, 5 630 Impact analysis activities, EIA, 10 236 Impact analysis, EIA, 10 240t Impact assessment types, 10 230, 231t Impact categories, in life cycle assessment, 14 817-818... 

The SSG was created in this manner to give a broad overview of the EHS performance profile of solvents and highlight any areas that would have major issues to eliminate, mitigate, or manage. The most recent addition to the SSG was the LCA score. The LCA score is based on a life cycle inventory (LCI) of each solvent and includes the impact categories shown in Table 3.6. The unique aspect of the LCA score is that it is based on a very comprehensive list of factors which contribute to a solvent s environmental impact, which includes the waste generation from... 

LCIA provides indicators for the interpretation of the inventory data in terms of contributions to different impact categories. The indicator results of an LCIA facilitate the evaluation of a product, and each stage in its life cycle, in terms of climate change, toxicological stress, noise, land use, water consumption, etc. The scope of the evaluation is, with some exceptions, limited to impacts at a regional and global scale. 

The overall indicator results of an LCIA reflect cumulative contributions to different impact categories that are summed over time and space. Unlike some other assessment approaches, these indicator results usually do not reflect risks or impacts at any particular location or point in time. The consumption of resources and the generation of wastes, emissions, etc., often occur in a product s life cycle ... 

For wastes and emissions, the inventory data in eqn (1) are in terms of the mass of each substance that is released into the environment associated with the functional unit. For example, the mass of the different chemicals released into the environment that are associated with all of the life cycle stages related to providing packaging for 1 m of packaged and delivered product. The characterization factors in eqn (1) therefore linearly express the contribution to an impact category of releasing a unit mass (e.g., 1 kg) of an emission into the environment. 

It is important to additionally account for differences in potential toxicological consequences (severity, damage, or impact) in the comparison. Characterization factors can be expressed in terms of metrics such as DALYs (disability adjusted life years) for human health, for example. The results for toxicological impacts can be directly cross-compared with those of DALY-based indicators for other impact categories, such as for climate change. 

The quantitative assessment of environmental impacts can be made using life-cycle assessment (LCA) methodology, which accounts for both inputs and emissions. LCA can be used to identify the major environmental impact categories and the sources of those impacts within a chemical processing plant. LCA can also be used to identify the major contributions to environmental impact within a product s life cycle. Impact scores derived from LCA can be used along with economic assessment scores and social indicators to provide indicators of overall sustainability of processes and products. Economic assessments are often limited through failure to account for all internal costs and especially the external costs associated with waste. 

Figure 3 Results of a cradle to grave life cycle comparison of five environmental impact categories of the traditional chemical (solid bars) and both the Bacillus subtilis and Ashbya gossypH-based microbial riboflavin production processes (checker board bars).

Thus, we can see that the studies published on bioplastics generally look at different impact categories, and rarely with the same computational methods. In addition, we need to take account of the fact that the goals and scopes of the studies are also variable, as are the functional units defined (simple lifecycle inventories as well as complete LCAs can be fonnd some studies are performed from cradle to factory gate for pellets or finished products, whereas other studies also integrate one or more end-of-life scenarios). In such conditions, it is understandable that it is not easy to write a coherent summary of publications relating to LCA of bioplastics in order to provide a simple response to the question Are bioplastics green plastics ... 

From Table 13.5, it is evident that if the cotton bags are not reused, this wUl pose a very severe threat to the environment, and if they are used 173 times (as determined by this particular study), the environmental impacts are significantly reduced. From the life cycle impact assessment results, it was noticed that the material extraction and production contributed to almost more than 98% to all the impact categories (this might be... 

FIGURE 61.3 LCA midpoint and endpoint impact categories. (From UNEP/SETAC LCI, Towards a life cycle sustainability assessment Making informed choices on products, Job Number DTI/1412/PA, Stockholm, 86p, 2011 Jolliet, O. et al., Int. J. Life Cycle Assess., 8(6), 324, 2003.)... 

The methodological and scientific framework for impact assessment is still being developed. Models for impact categories are in different stages of development. There is subjectivity in the life cycle impact assessment phase such as the choice, modelling and evaluation of impact categories. Therefore, transparency is critical to impact assessment to ensure that the assumptions are clearly described and reported. 

LCIA operates on the inventory of elementary flows for the product life cycle (input of resources and output of emissions) into potential impacts on the environment. These inventory flows are translated into scores for indicators that represent impact on human health, natural environment, and natural resources within a number of predefined impact categories (EC-IRC 2011). 

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