HOME SITEMAP CONTACT US

• Newsletter.1 - HEROIC – An Introduction
• Newsletter.1-We are HEROICs and how we work
• Newsletter.1 - Focus on HEROIC partners
• Newsletter 2 Strengths, weaknesses/limitations, opportunities, and threats (SWOT): analysis of the "as is" situation in RA
• Newsletter 2 The accessibility of available data: the Tox-Hub platform
• Newsletter 2 Focus On Heroic Partners
• Newsletter 3 Focus On Heroic Partners
• Newsletter 3 Examination and inventory of endpoints, data and models available for hazard and exposure assessment
• Newsletter 4 integrated risk assessment of chemical mixture
• Newsletter 4 Focus On Heroic Partners
• Newsletter 5 HEROIC consultation workshop on expert elicitation
• Newsletter 5 Expert Workshop on Extrapolation for Hazard Assessment
• Newsletter 5 Stakeholders consultation on potential socio-behaviour factors
• Newsletter 5 Focus on Heroic partners
• Newsletter 6 HEROIC roadmap to the white paper on policy and technical recommendations
• Newsletter 6 HEROIC Expert workshop on extrapolations in integrated exposure assessment, Paris, January 21-22, 2014
• Newsletter 6 HEROIC Focus on Heroic partners
• Newsletter 6 HEROIC Expert roundtable on socio-behavioural factors in risk analysis policy making
• Newsletter main page

Newsletter 4 Integrated Risk Assessment Of Chemical Mixture

The integration of human risk assessment (HRA) and environmental risk assessment (ERA) in a single process, could also be extended from hazard and exposure assessments for single chemicals to realistic situations of exposure to multi-component mixtures of chemicals.

An updated inventory of existing approaches and methodologies for assessing the toxicity of chemical mixtures and cumulative risks was prepared within the framework of WP3, taking into account recent reviews and discussion papers on methodological and regulatory aspects of the subject, proposals for novel approaches, new comprehensive books on mixture toxicology, new proposals for tiered regulatory approaches for mixture risk assessment and the recent Communication from the European Commission on the issue

Regulatory approaches to the problem of mixture toxicity fall into three basic categories: experimental whole mixture testing, component-based mixture toxicity modelling, and safeguarding against unwanted mixture effects by means of assessment factors.  As an update of the state-of-the art report on mixture toxicity that was prepared in 2009 for the European Commission, we examined all new scientific concepts and models, as well all current regulatory approaches to the issue. On occasion of the first HEROIC workshop, the resulting inventory was discussed with a panel of invited experts, with the aim to identify those new approaches that may become fit for regulatory purposes in the near future, and more specifically to identify those methodologies that lend themselves for an integrated approach that combines human and environmental risk assessment of chemical mixtures in a coherent procedure.

During recent years, several European, American and internal organisation have proposed different generic frameworks for assessing the risks from exposure of humans or wildlife to multi-component chemical mixtures. These are important steps forward, but the experts agreed that none of the proposals already fits all regulatory needs. A number of developing methodologies were considered to be potentially helpful for improving the process, such as the TTC approach (Threshold of Toxicological Concern) for human risk assessments or the SSD concept (Species Sensitivity Distribution) for ecotoxicological mixture risk assessments. Other novel approaches appear to be promising form a scientific perspective but were considered to be far away from being fit for regulatory purposes, such as the application of the so-called omics-approaches or the DEB theory (Dynamic Energy Budget), for instance.

For more detailed information please contact: Michael Faust (faust@fb-envico.com).