【正文】 FOREWORD Concise International Chemical Assessment Documents (CICADs) are the latest in a family of publications from the International Programme on Chemical Safety (IPCS) – a cooperative programme of the World Health Organization (WHO), the International Labour Organization (ILO), and the United Nations Environment Programme (UNEP). CICADs join the Environmental Health Criteria documents (EHCs) as authoritative documents on the risk assessment of chemicals. International Chemical Safety Cards on the relevant chemical(s) are attached at the end of the CICAD, to provide the reader with concise information on the protection of human health and on emergency action. They are produced in a separate peerreviewed procedure at IPCS. CICADs are concise documents that provide summaries of the relevant scientific information concerning the potential effects of chemicals upon human health and/or the environment. They are based on selected national or regional evaluation documents or on existing EHCs. Before acceptance for publication as CICADs by IPCS, these documents undergo extensive peer review by internationally selected experts to ensure their pleteness, accuracy in the way in which the original data are represented, and the validity of the conclusions drawn. The primary objective of CICADs is characterization of hazard and doseresponse from exposure to a chemical. CICADs are not a summary of all available data on a particular chemical。 rather, they include only that information considered critical for characterization of the risk posed by the chemical. The critical studies are, however, presented in sufficient detail to support the conclusions drawn. For additional information, the reader should consult the identified source documents upon which the CICAD has been based. Risks to human health and the environment will vary considerably depending upon the type and extent of exposure. Responsible authorities are strongly encouraged to characterize risk on the basis of locally measured or predicted exposure scenarios. To assist the reader, examples of exposure estimation and risk characterization are provided in CICADs, whenever possible. These examples cannot be considered as representing all possible exposure situations, but are provided as guidance only. The reader is referred to EHC While every effort is made to ensure that CICADs represent the current status of knowledge, new information is being developed constantly. Unless otherwise stated, CICADs are based on a search of the scientific literature to the date shown in the executive summary. In the event that a reader bees aware of new information that would change the conclusions drawn in a CICAD, the reader is requested to contact IPCS to inform it of the new information. Procedures The flow chart shows the procedures followed to produce a CICAD. These procedures are designed to take advantage of the expertise that exists around the world – expertise that is required to produce the highquality evaluations of toxicological, exposure, and other data that are necessary for assessing risks to human health and/or the environment. The IPCS Risk Assessment Steering Group advises the Coordinator, IPCS, on the selection of chemicals for an IPCS risk assessment based on the following criteria: ? there is the probability of exposure。 and/or ? there is significant toxicity/ecotoxicity. Thus, a priority chemical typically ? is of transboundary concern。 ? is of concern to a range of countries (developed, developing, and those with economies in transition) for possible risk management。 ? is significantly traded internationally。 ? has high production volume。 ? has dispersive use. The Steering Group will also advise IPCS on the appropriate form of the document (., EHC or CICAD) and which institution bears the responsibility of the document production, as well as on the type and extent of the international peer review. The first draft is based on an existing national, regional, or international review. Authors of the first draft are usually, but not necessarily, from the institution that developed the original review. A standard outline has been developed to encourage consistency in form. The first draft undergoes primary review by IPCS to ensure that it meets the specified criteria for CICADs. The second stage involves international peer review by scientists known for their particular expertise and by scientists selected from an international roster piled by IPCS through remendations from IPCS national Contact Points and from IPCS Participating Institutions. Adequate time is allowed for the selected experts to undertake a thorough review. Authors are required to take reviewers39。 ments into account and revise their draft, if necessary. The resulting second draft is submitted to a Final Review Board together with the reviewers39。 ments. At any stage in the international review process, a consultative group may be necessary to address specific areas of the science. Advice from Risk Assessment Steering Group Criteria of priority: ? there is the probability of exposure。 and/or ? there is significant toxicity/ ? ecotoxicity. Thus, it is typical of a priority chemical that ? it is of transboundary concern。 ? it is of concern to a range of countries (developed, developing, and those with economies in transition) for possible risk management。 ? there is significant international trade。 ? the production volume is high。 ? the use is dispersive. Special emphasis is placed on avoiding duplication of effort by WHO and other international anizations. A prerequisite of the production of a CICAD is the availability of a recent highquality national/regional risk assessment document = source document. The source document and the CICAD may be produced in parallel. I