Green benchmarking

In this chapter, we focus on strategies, tools and metrics that help chemical choosers to green their chemical product inventories and to benchmark progress. The term chemical chooser applies to those who purchase chemicals for use in the development of formulated products or those who purchase formulated chemical products for use in their use in activities such as maintenance, repair and operations. Most product manufacturers are chemical and material choosers in contrast to chemical or raw material manufacturers who process, synthesize and supply chemicals as raw materials. 

All of the hazard and benchmark criteria developed for the Green Screen are presented in the report, along with information on government and other precedents for classification that were used to help establish the thresholds. The hst of hazard categories and threshold values used to define levels of concern in the Green Screen are presented in Table 8.1. 

The Green Screen defines four benchmarks on the path to safer chemicals ... 

Figure 8.3 The Green Screen for Safer Chemicals Benchmarks. Reproduced with permission of Clean Production Action.

Benchmark 2 continues the emphasis on persistence, bioaccumulation, and toxicity, but at lower threshold values. In addition. Benchmark 2 includes flammability and explosiveness. It is anticipated that many chemicals will not move past Benchmark 2 because of the broad scope of hazards and challenging threshold values included in the Green Screen. 

Benchmark 4 Prefer - Safer Chemical. Only organic chemicals with low inherent toxicity to humans and wildlife, that do not bio accumulate, and rapidly and completely degrade to benign degradation products or metabolites reach Benchmark 4. These are chemicals that would meet the principles of green chemistry that relate to hazard. 

The Green Screen includes a chemical s breakdown products, that is, metabolites and degradation products in a hazard assessment because they may be more hazardous than the parent compound. The final benchmark for a parent chemical is the lowest benchmark achieved by either it or its breakdown products. For example, if a parent chemical achieved Benchmark 2, but its breakdown product achieved Benchmark 1, the final benchmark for the parent chemical is Benchmark 1. Thus the degradation product or metabolite of a chemical is considered equivalent to the parent compound with respect to its benchmark unless it can be demonstrated that the breakdown product is insignificant (i.e., transient, not actually formed, etc.). 

The Green Screen is a much needed method for comparing and benchmarking chemicals based on hazard. Green Screen assessments can be incorporated into broader alternatives... 

Defining positive as the absence of hazard. Using Clean Production Action s Green Screen, the ideal chemicals are defined as those that have low hazard for all relevant hazard endpoints as exemplified by Benchmark 4. While it is anticipated that the majority of chemicals will not ciurently reach Benchmark 4, it is stiU important to have a vision of what good (and... 

The results of the application concluded that of the three flame retardants, RDP was the only flame retardant to pass all criteria under Benchmark 1 of the Green Screen. Based on... 

The Green Chemistry Institute (GCl) Pharmaceutical Roundtable has used the Process Mass Intensity (PMl) [12], defined as the total mass used in a process divided by the mass of product (i.e. PMl = E factor -i- 1) to benchmark the environmental acceptability of processes used by its members (see the GCl website). The latter include several leading pharmaceutical companies (Eh Lilly, GlaxoSmithKline, Pfizer, Merck, AstraZeneca, Schering-Plow, and Johnson Johnson). The aim was to use this data to drive the greening of the pharmaceutical industry. We believe, however, that the E factor is to be preferred over the PMl since the ideal E factor of 0 is a better reflection of the goal of zero waste. 

The OsPar Convention for the North East Atlantic has set the generational goal of eliminating hazardous emissions within one generation, or by the year 2020. Such a timeline has also been adopted by the Swedish government in their new chemical policy and this provides a benchmark by which the transition to green chemistry and safer materials can be measured. No other country has detailed such a clear set of criteria and goals to achieve a nontoxic future. ... 

Early pioneers in green chemistry included Trost (who developed the atom economy principle) and Sheldon (who developed the E-Factor). These measures were introduced to encourage the use of more sustainable chemistry and to provide some benchmarking data to encourage scientists to aspire to more benign synthesis. 

These results are helpful in providing some benchmark figures which, as new green chemistry/technology options increase in the future, can be expected to be improved on for the compounds that are at the beginning of their development programme. 

With the enormous breadth of the chemical sciences, it was necessary to divide chemistry into 11 areas, each of which is also extremely broad. Undoubtedly, some areas have been left out. The U.S. standing in green chemistry/engineering, sustainability, and energy production was not addressed because the subjects are being covered extensively in the related benchmarking study of U.S. chemical engineering research. 

In addition, it is designed to identify safer chemicals based upon the best available data (be it experimental or analog data) and to inform decisions by businesses, governments, as well as individuals concerned with the risks posed by chemicals. At the heart of the Green Screen are four benchmarks that define a path to preferred chemicals that are safer and healthier for humans and the environment. 

Finally it has modules or tools for evaluating alternatives based on concerns for human health and the environment, social justice, economic feasibility or technical performance. As part of an alternatives assessment framework, the Green Screen is designed, as illustrated in Figure 1,for benchmarking chemicals (not materials or products). 

The vision of a non-toxic environment is embedded into the Green Screen through the focus on hazards (and not risks), the setting of threshold values for defining levels of concern for chemical hazards, the setting of benchmarks, and in the interpretation of evidence of harm from experimental data. Our goal is to promote the development of products made from chemicals and materials that meet the highest levels of environmental health performance. 

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