Environmental hazard assessments for chemicals are carried out to define an environmentally "safe" level at which, theoretically, the chemical will not negatively affect any exposed biota. Despite this common goal, the methodologies in use are very diverse across different countries and jurisdictions. This becomes particularly obvious when international scientists work together on documents with global scope, e.g., in the World Health Organization (WHO) International Program on Chemical Safety. In this article, we present a study that describes the extent of such variability and analyze the reasons that lead to different outcomes in deriving a "safe level" (termed the predicted no effect concentration [PNEC] throughout this article). For this purpose, we chose 5 chemicals to represent well-known substances for which sufficient high-quality aquatic effects data were available: ethylene glycol, trichloroethylene, nonylphenol, hexachlorobenzene, and copper (Cu). From these data, 2 data sets for each chemical were compiled: the full data set, that contained all information from selected peer-review sources, and the base data set, a subsample of the full set simulating limited data. Scientists from the European Union (EU), United States, Canada, Japan, and Australia independently carried out hazard assessments for each of these chemicals using the same data sets. Their reasoning for key study selection, use of assessment factors, or use of probabilistic methods was comprehensively documented. The observed variation in the PNECs for all chemicals was up to 3 orders of magnitude, and this was not simply due to obvious factors such as the size of the data set or the methodology used. Rather, this was due to individual decisions of the assessors within the scope of the methodology used, especially key study selection, acute versus chronic definitions, and size of assessment factors. Awareness of these factors, together with transparency of the decision-making process, would be necessary to minimize confusion and uncertainty related to different hazard assessment outcomes, particularly in international documents. The development of a "guideline on transparency in decision-making" ensuring the decision-making process is science-based, understandable, and transparent, may therefore be a promising way forward.

Integrated Environmental Assessment and ManagementVolume 5, Issue 1 p. 175-177 Special Series Reducing uncertainty in environmental risk assessment (era): clearly defining acute and chronic toxicity tests Torsten Hahn, Torsten Hahn Fraunhofer ITEM, Hannover, GermanySearch for more papers by this authorJenny Stauber, Corresponding Author Jenny Stauber [email protected] Centre for Environmental Contaminants Research, CSIRO Land and Water, Sydney, AustraliaCentre for Environmental Contaminants Research, CSIRO Land and Water, Sydney, AustraliaSearch for more papers by this authorStuart Dobson, Stuart Dobson Centre for Ecology and Hydrology, Monks Wood, United Kingdom, USASearch for more papers by this authorPaul Howe, Paul Howe Centre for Ecology and Hydrology, Monks Wood, United Kingdom, USASearch for more papers by this authorJanet Kielhorn, Janet Kielhorn Fraunhofer ITEM, Hannover, GermanySearch for more papers by this authorGustav Koennecker, Gustav Koennecker Fraunhofer ITEM, Hannover, GermanySearch for more papers by this authorJerry Diamond, Jerry Diamond Tetra Tech, Owings Mills, MD, USASearch for more papers by this authorChris Lee-Steere, Chris Lee-Steere Australian Environment Agency, Deakin, ACT, AustraliaSearch for more papers by this authorUwe Schneider, Uwe Schneider National Standards and Guidelines Office, Environment Canada, Gatineau, QC, CanadaSearch for more papers by this authorYoshio Sugaya, Yoshio Sugaya National Institute for Environmental Studies, Ibaraki, JapanSearch for more papers by this authorKen Taylor, Ken Taylor Existing Substances Division, Environment Canada, Gatineau, QC, CanadaSearch for more papers by this authorRick Van Dam, Rick Van Dam Environmental Research Institute of the Supervising Scientist, Darwin, AustraliaSearch for more papers by this authorInge Mangelsdorf, Inge Mangelsdorf Fraunhofer ITEM, Hannover, GermanySearch for more papers by this author Torsten Hahn, Torsten Hahn Fraunhofer ITEM, Hannover, GermanySearch for more papers by this authorJenny Stauber, Corresponding Author Jenny Stauber [email protected] Centre for Environmental Contaminants Research, CSIRO Land and Water, Sydney, AustraliaCentre for Environmental Contaminants Research, CSIRO Land and Water, Sydney, AustraliaSearch for more papers by this authorStuart Dobson, Stuart Dobson Centre for Ecology and Hydrology, Monks Wood, United Kingdom, USASearch for more papers by this authorPaul Howe, Paul Howe Centre for Ecology and Hydrology, Monks Wood, United Kingdom, USASearch for more papers by this authorJanet Kielhorn, Janet Kielhorn Fraunhofer ITEM, Hannover, GermanySearch for more papers by this authorGustav Koennecker, Gustav Koennecker Fraunhofer ITEM, Hannover, GermanySearch for more papers by this authorJerry Diamond, Jerry Diamond Tetra Tech, Owings Mills, MD, USASearch for more papers by this authorChris Lee-Steere, Chris Lee-Steere Australian Environment Agency, Deakin, ACT, AustraliaSearch for more papers by this authorUwe Schneider, Uwe Schneider National Standards and Guidelines Office, Environment Canada, Gatineau, QC, CanadaSearch for more papers by this authorYoshio Sugaya, Yoshio Sugaya National Institute for Environmental Studies, Ibaraki, JapanSearch for more papers by this authorKen Taylor, Ken Taylor Existing Substances Division, Environment Canada, Gatineau, QC, CanadaSearch for more papers by this authorRick Van Dam, Rick Van Dam Environmental Research Institute of the Supervising Scientist, Darwin, AustraliaSearch for more papers by this authorInge Mangelsdorf, Inge Mangelsdorf Fraunhofer ITEM, Hannover, GermanySearch for more papers by this author First published: 05 November 2009 https://doi.org/10.1897/1551-3793-5.1.175Citations: 3Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL No abstract is available for this article.Citing Literature Volume5, Issue1January 2009Pages 175-177 RelatedInformation

Paul D. Howe1, Trevor T. Griffiths2, Stuart Dobson1 & Heath M. Malcolm3 1 CEH Monks Wood, Abbots Ripton, Huntingdon, Cambridgeshire U.K.; 2 QinetiQ, Fort Halstead, Sevenoaks, Kent U.K.; 3 CEH Edinburgh, Bush Estate, Penicuik, Midlothian U.K. Introduction Screening level summary reports have been produced, as part of a SERDP contract, on the known human and ecological toxicology, and environmental mobility (aquatic and terrestrial) of compounds used in selected pyrotechnic formulations. Persistence, bioaccumulation and toxicity criteria (as outlined below) were used to identify the formulations which would be used in a computer combustion model. The combustion products have now been reviewed.

Glyphosate-based weed control products are among the most widely used broad-spectrum herbicides in the world. The herbicidal properties of glyphosate were discovered in 1970, and commercial formulations for nonselective weed control were first introduced in 1974 (Franz et al. 1997). Formulations of glyphosate, including Roundup® Herbicide (RU)1 (Monsanto Company, St. Louis, MO), have been extensively investigated for their potential to produce adverse effects in nontarget organisms. Governmental regulatory agencies, international organizations, and others have reviewed and assessed the available scientific data for glyphosate formulations and independently judged their safety. Conclusions from three major organizations are publicly available and indicate RU can be used with minimal risk to the environment (Agriculture Canada 1991; USEPA 1993a; WHO 1994). Several review publications are available on the fate and effects of RU or glyphosate in the environment (Carlisle and Trevors 1988;Smith and Oehme 1992 ; Malik et al. 1989;Rueppel et al. 1977; Sullivan and Sullivan 1997;Forestry Canada, 1989). In addition, several books have been published about the environmental and human health considerations of glyphosate and its formulations (Grossbard and Atkinson 1985; Franz et al. 1997). In addition, RU and other glyphosate formulations have been selected for use in a number of weed control programs for state and local jurisdictions in the United States. Many of these uses require that ecological risk assessments be conducted in the form of Environmental Impact Statements or Environmental Assessments. These documents are comprehensive and specific to local use situations. Documents are available for risk assessments in Texas, Washington, Oregon, Pennsylvania, New York, Virginia, and other states (USDA 1989;USDA 1992;USDA 1996;USDA 1997;USDI 1989; Washington State DOT 1993).