Environmental Hazards and Risk

There are a number of ways to approach the assessment of the environmental risk that may be associated with a process. Whatever strategy might be chosen, however, some general risk areas should be part of the overall assessment. First, the inherent hazard, fate, and effects of the materials in the process need to be determined and assessed from an environmental perspective. Second, the potential for any process or unit operations releases need to be identified and evaluated. Third, environmental impacts from transportation, storage, and disposal options associated with the materials used in the process need to be identified and evaluated. Finally, the environmental life cycle impacts of producing those materials need to be collected and assessed. 

It should be understood that to develop process metrics based on a credible risk assessment will require a considerable number of tests to assess appropriately the potential environmental hazards associated with the process and the materials used in the process. One typically needs to screen compounds to assess their environmental hazard and their tendency for persistence, bioaccumulation, and toxicity. Depending on how a compound is ultimately used, environmental testing might lead you to the conclusion that it is best to avoid the commercial production of a particular compound. Alternatively, you might devise a process that uses the compound but controls the environmental risk to acceptable levels. For the latter case, performing a process-specific risk assessment would be imperative to assess the impact of the inherent hazard and environmental fate and effects of a given chemical or set of chemicals. In addition, the unique characteristics of the process, available treatment, and volumes will need to be taken into consideration. 

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World Bank (1997). Environmental Hazard and Risk Assessment. In Environmental Assessment Sourcebook. Update No. 21. Washington, DC World Bank. 

Ecological and toxicological association of the dyestuff manufacturing industry (ETAD). E 3022 Environmental hazard and risk assessment in the context of EC directive 79/831/ from 31 May 1991. 

Nabholz, 3.V. 1991. Environmental hazard and risk assessment under the United States Toxic Substances Control Act. Sci. Total Environ. 109/110 649-665. 

Facilitate the use of available evaluations of health and environmental hazards and risks from chemicals ... 

Predictive QSARs are studies aimed at providing estimates for endpoints and parameters required in environmental hazard and risk assessment. This is a demanding goal, which should be strived for only if the principal shortcomings of the approach are considered, otherwise there is the danger of running into scientifically obscure imponderables. 

The data sets required for the assessment of environmental hazard and risk resulting from the use of chemicals include information on persistence, accumulation, mobility and ecotoxicity. The basic concept of environmental risk assessment is a comparison of the levels of exposure and toxicity (Part 3). An evaluation is made of the probability that the exposure level of potential contaminants may exceed effective, toxic concentrations in the environmental compartment of concern. The severity of the impact is also taken into consideration. The respective exposure and effects concentrations are determined from experimental or, if not available, QSAR data (Nendza, Volmer and Klein, 1990). For that, compound-specific data are required in addition to information on the release rates and the environmental scenario of concern ... 

Application of QSARs in Environmental Hazard and Risk Assessments... 

The considerable lack of experimental data for the fate and effects assessment of environmental contaminants requires the provisional use of substitutes. For this purpose, QSAR estimates are superior to the alternative of using uniform default values, which do not allow differentiation and ranking of the potential hazards of diverse chemicals. QSAR data-quality requirements for assessing environmental hazards and risks have to be evaluated relative to the quality of the available experimental data and the relevance of the accuracy of the individual data for subsequent hazard and risk classifications. Within these assessment schemes, several factors are usually ignored for the sake of scientific precision and standardization. The simplifications of the real world apply, regardless of whether experimental or calculated input data are used ... 

The information necessary for the assessment of environmental hazard and risk, resulting from the use of chemicals, is preferably obtained from field monitoring and laboratory studies, but often it has to be supplemented by estimates based on various modelling techniques. The input data set required for risk assessments comprises data on the persistence, accumulation, mobility and ecotoxicity of chemicals as well as detailed information on the particular environment, to estimate in stepwise fashion the exposure concentration and the toxic levels for a regional scenario (Figure 9.1). 

Strategy based on preventive actions, when the company is concentrating on the prevention of environmental hazards and risks. 

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