The OECD Environmental, Health and Safety (EHS) Programme has been helping member countries to make better use of increased knowledge of how chemicals induce adverse effects in humans and wildlife, through the so-called Adverse Outcome Pathways.

 

What's new

The OECD released three webinar video recordings on Adverse Outcome Pathways:

• Adverse Outcome Pathways Framework, Tuesday 30 April 2019
  This first webinar on Adverse Outcome Pathways (AOPs) discussed the Adverse Outcome Pathway (AOP) framework. The AOP framework is a collaborative tool that applies an innovative approach for collecting mechanistic knowledge from various sources that can eventually support chemical safety assessment.
  
  
• Adverse Outcome Pathways: Assembling and evaluating weight of evidence and quantitative understanding - Wednesday 15 January 2020
  This second webinar on Adverse Outcome Pathways (AOPs) focused on the importance of weight of evidence in the process of developing AOPs, the types and lines of evidences assembled, examples demonstrating the lines of evidence and understanding why quantitative AOPs are developed. The AOP framework is a collaborative tool that applies an innovative approach for collecting mechanistic knowledge from various sources that can eventually support chemical safety assessment.
  
  
• Adverse Outcome Knowledge Base (AOP-KB) and AOP developing tips - Thursday 30 January 2020
  The third webinar on Adverse Outcome Pathways (AOPs) focused on the core information and telecommunication technologies applications that were built to support AOP development, management and dissemination. Tools and technical tips to facilitate scientific knowledge assembling and evaluations were also presented. The AOP framework implements a collaborative and innovative approach for collecting mechanistic knowledge from various sources that can eventually support chemical safety assessment.
  
  
• Access all the presentations 
  
  
  

What is an Adverse Outcome Pathway?

The OECD launched a new programme on the development of Adverse Outcome Pathways (AOP) in 2012. An AOP is an analytical construct that describes a sequential chain of causally linked events at different levels of biological organisation that lead to an adverse health or ecotoxicological effect (see figure below). AOPs are the central element of a toxicological knowledge framework being built to support chemical risk assessment based on mechanistic reasoning.

 

Schematic representation of the AOP illustrated with reference to a number of pathways

 

Watch our video: OECD work on Adverse Outcome Pathway

 

Publications on Adverse Outcome Pathways

Access all publications on Adverse Outcome Pathways here. 

 

The AOP Development Programme

The AOP development programme is overseen by the extended Advisory Group on Molecular Screening and Toxicogenomics (EAGMST). EAGMST members are nominated by their National Coordinators; they play an active role in the development of AOPs, as well as in the internal review process.

• Find the OECD's Series on Adverse Outcome Pathways.
• The development of an AOP can be proposed by research teams in OECD countries. Form to complete and submit an AOP Project proposal.
• The users' handbook for AOP development should be followed as it provides practical guidance for developing an AOP in the AOP Wiki platform.
• The AOP workplan is updated in June and December every year.
• AOP development and review process at OECD.

Representation of the AOP Development Process

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AOP Knowledge Base and Tools

The OECD's AOP Knowledge Base tools, constantly developed and refined, are a web-based platform which aims to bring together all knowledge on how chemicals can induce adverse effects, therefore providing a focal point for AOP development and dissemination.

The e AOP Portal is the main entry point of the AOP Knowledge Base. A search engine, the Portal enables search by key words in AOP titles and key events in the AOP Wiki and Effectopedia platforms. It houses the status of all AOPs in the OECD Work Plan and the official copy of OECD endorsed AOPs.

The AOP Wiki provides a system that organises, via crowd-sourcing, the available knowledge and published research into a verbal description of individual pathways, using a user friendly Wiki interface. Information on AOP is collected in a qualitative, narrative way.

Effectopedia is an open-knowledge and structured platform able to display information on Adverse Outcome Pathways. It uses visually expressed modular structures to capture semantically annotated knowledge and algorithms together with all the supporting evidence.

Find out more

Test Guidelines Programme The OECD Test Guidelines Programme for the identification of new biomaker endpoints and in vitro test methods that are candidates to become part of OECD Test Guidelines.

Hazard Assessment Activities The OECD Hazard Assessment activities for the development of Integrated Approaches to Testing and Assessment (IATA, using AOPs as a framework. The OECD QSAR project for the identification of new methods/profilers for grouping chemicals.

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