Chemical sustainability measurment, indicators

The continuing development of available labels remains one of the most promising avenues for advances in chemical imaging in both biological and soft materials applications. Figure 3.3 illustrates the GFP-RFP varieties available today. However, they are not optimal because they require slow oxidative activation within the cells in which they are expressed and are therefore not sufficient indicators for many dynamic measurements of gene expression. Current research aims to escape this kind of problem by the development of unnatural amino acids that can be expressed as intracellular markers. This difficult area requires sustained and concerted support. 

Efforts to develop sustainability indicators and metrics have been made at various scales, ranging from global down to local community, business unit, and technology levels. In general, indicators and metrics are designed to capture the ideas inherent in sustainability and transform them into a manageable set of quantitative measures and indices that are useful for communication and decision-making. In this section, we provide an overview of sustainability indicators and metrics, especially as they relate to the chemical industry. This section will be followed by two specific case studies on the uses of sustainability metrics and indicators in product/process development in chemical companies. 

Sustainability and Performance, MIT Sloan Management Review, Winter 2003 and C. B. Cobb, Measuring What Matters Value Creation Indices in the Utilities and Chemical Industries, CBEY Center for Business Innovation. 

The replacement of hazardous chemicals with benign and inherently safer alternatives indicated by green chemistry principles is certainly a valuable measure, because a hazardous chemical that is no longer present can no longer be involved in an accident. However, from industrial point of view there are often alternative solution that reduce the risk to a sustainable level at a much lower cost than that required by completely changing the production. 

A chemical substance is safe for a certain use if it is demonstrated that it poses no risk when taking into consideration risk reduction measures that reduce exposure of man or environment [86-88]. However, this is not enough to indicate that it is also a sustainable chemical. A sustainability target consists of the development of inherently safe chemicals (ISCs), for example, without risks for human health and the environment, even without specific exposure control. 

As discussed for mass intensity indicators, energy intensity indicators are simple to calculate but give only a partial overview of sustainability, as processes outside the chemical reaction or the chemical plant are not included. In addition, no discrimination is made between renewable and non-renewable sources, which have very different implications with regard to sustainability. Finally, the energy intensity related to material production (reactants, solvents, etc.) is also not included. As a consequence, energy intensity indicators must always be accompanied by material intensity indicators, which are measured in different units and cannot be directly aggregated. 

Table 5.4 Indicators for measuring the sustainability of a chemical process.

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