Review Articles Chemicals Regulation Assessment

Chemicals Regulation Assessment

Environmental Hazard

- Assessment of Chemicals and Products

Part I: General Assessment Principles Part II: Persistence and Degradability of Organic Chemicals* Part III: The Limits to Single Compound Assessment Part IV: Life Cycle Assessment (LCA)

* Parts llI - IV will be published in the following issues of ESPR.

Walter K16pffer

C. A. U. GmbH, Daimlerstrafle 23, D-63303 Dreieich/Frankfurt, Germany

Survey on the Series

- Abstracts of Parts I - IV

Part I: General Assessment Principles

Hazard assessment is based both on estimates of environmental ex- posure and ecotoxic, toxic, and other noxious effects. Environmental criteria are given to enable a preliminary categorization of the haz- ard posed by a chemical. Depending on the amount and quality of data, the hazard estimates may be very rough (so that large safety margins are required), or more or less satisfactory. Risk assessment (not considered in detail) requires sufficient quantitative information, not available for most chemicals. Scoring systems give first approximations if many chem- icals are to be assessed with a minimum amount of data. More elaborate hazard assessment systems are shortly discussed. A main problem of all assessment procedures are the extremely to- xic chemicals with no or very small production and the persistent chemicals without known adverse effects. Suggestions are made how to deal with these difficult cases.

Part II: Persistence and Degradability of Organic Chemicals

The criteria "Persistence" and "Degradability" are defined and ex- plained, starting from the "functional" definition of the environment. In this definition, the environment is the counterpart of the techno- sphere, which consists of all processes controlled by man. A sub- stance is persistent if there are no sinks (degradation processes). It is shown that persistence is the central and most important crite- rium of environmental hazard assessment of organic chemicals. It follows that all substances released into the environment should be degradable, preferentially into small inorganic molecules (mineral- ization). As examples for persistent substances, the polychlorina- ted biphenyls (PCB), the chlorofluorohydrocarbons (CFC), bis(2- ethylhexyl) phthalate (DEHP), and 2,3,7,8-tetrachloro-dibenzo- dioxin (TCDD) are discussed. Finally, an attempt to quantify per- sistence is made.

Part III: The Limits to Single Compound Assessment

The principles and basic assumptions of single compound assess- ment are briefly reviewed. Limitations to this approach are shown, especially with regard to complex mixtures of similar substances, substitution products, and complicated (final) products containing chemicals and materials produced by the chemical industry. A new thinking in product lines and life cycles is emerging, leading to new assessment methods. In some cases, substitution has not improved the environmental performance of products, since very similar chem- icals were used as substitutes.

Part IV: Life Cycle Assessment (LCA)

The first LCAs (or eco-balances) were carried out in about 1970 when energy saving became a topic of general concern. Further pio- neering work was performed in the 80's, but public interest has been induced only in the last few years. A modern LCA, as defined by SETAC, consists of four main com- ponents: Goal Definition, Inventory, Impact Assessment (including Valuation), and Improvement Analysis. The backbone of each LCA is the Inventory, a quantitative cradle- to-grave analysis of all relevant mass and energy fluxes related the product(s) or systems studied, including the toxic or ecotoxic emis- sions. Impact Assessment is the environmental assessment of the emissions according to a set of criteria. In the broader approach (much dis- cussed in Germany) of "Produktlinienanalyse", social and economic impacts are also considered in the Impact Assessment component. Impact Assessment also contains the "Valuation"-step which goes beyond (exact) science due the to normative and subjective factors invariably involved. Therefore, LCAs cannot replace political and economic decisions, but rather provide more rational (as opposed to emotional) and scientific foundations. The best use of LCA is the comparative assessment of products and systems serving the same purpose to improve manufacturing, waste management etc. over the whole life cycle. In order to compare dif- ferent products or systems, a "functional unit" has to be defined, allowing a fair comparison between the alternatives. All data (e.g. total energy consumption, emissions, wastes, impacts) are related to this functional unit, so that a quantitative and differentiated com- parison of different options becomes possible.

ESPR-Environ. Sci. & PoUut. Res. 1 (2) 107-116 (1994) 107 �9 ecomed publishers, D-86899 Landsberg, Germany