Impact categories

Selection of impact categories, category indicators, and models... 

The sum of indicator values obtained when multiplying all emissions assigned to that impact category by their respective characterization factors is called the category indicator result. The indicator moles of may, for instance, be the sum of contributions from sulfur dioxide, nitrogen oxides, and hydrogen chloride, and there is a characterization factor for each of them relative to the indicator. 

An indicator result could, for instance, be compared to the total indicator value in an area, or to the average indicator value per inhabitant per year. Other common methods are to compare with national reduction targets and with damage costs from emissions and resource depletion. Sometimes these are weighed across impact categories made by expert panels. However, some studies using this technique would not meet the requirement of transparency for the weighting process set by ISO. 

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

The boundary for LCA is substantially broader than that for mass balancing (Introduction). Impact categories of LCA are for example global warming, ozone depletion. 

The determination of the significant issues helps to structure the results from the LCI or LCIA phases according to the goal and scope of the study. Figure 7.3 demonstrates the reasons for the results obtained in the LCIA phase by means of two selected impact categories GWP and HTP. 

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 goal of the LCA is to understand the impact of the existing fluid milk supply chain on energy usage and GHG emissions, as well as the other impact categories provided that data are available, and to use the information as a roadmap for improvements to the process. The LCA also provides an environmental benchmark to identify points where improvements to the fluid milk supply chain may be made. 

With the LCA analysis, the impact categories - the impact on climate, water pollution and air pollution - are mostly evaluated. Whereas, impacts such as biodiversity or pesticide toxicity are seldom evaluated because of methodological problems [34]. The LCA study consists of four basic stages Definition of objectives and the scope, Inventory, Impact assessment and Interpretation [32]. 

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 results were calculated using the SIMA Pro software. To obtain the necessary results, the Recipe Midpoint (H) Europe method has been chosen as a characterization model. Results come from the climate change impact category and they are expressed in kg of a carbon dioxide equivalent (C02e). 

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

The data situation for additives in LCIA seems to be somewhat better than for the LCI [4]. Characterization factors exist for a number of additives and for a number of impact categories. Nevertheless, the fist is nowhere near complete. Especially for the impact categories of human toxicity and ecotoxicity, impact factors are missing. Approaches exist to calculate such factors based on substance characteristics. In this volume, LCIA factors are derived for a large number of additives based on such approaches [5]. The lack of such factors, therefore, seems to be less of a problem for including additives in LCA case studies than the lack of LCI data. 

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. 

Impact categories (model outputs) eco-toxicity impacts and/or human toxicity impact... 

Principal characteristics Impact categories Exposure routes Fate, exposure and effect... 

Principal characteristics Impact categories Exposure routes Fate, exposure and effect Chemical considered Media considered Spatial variation Source code availability Model availability Dynamic or steady-state Availability for sensitivity and uncertainty analyses... 

For the impact assessment, the midpoint method EDIP97 [15] was used, and the following impact categories were included ... 

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