Use and Update of OECD GDs/TGs

Use of OECD Test Guidelines (TGs) and Guidance documents (GDs) 

The use phase of OECD Test Guidelines (TGs) and Guidance Documents (GDs) follows their publication on the OECD website (See the Commenting and approval phase at OECD). 

Test methods described in OECD TGs/GDs generally imply a strong understanding of scientific principles, and technical expertise in relevant experimental procedures (e.g. technical laboratory equipment). They are used to determine the physicochemical, environmental, ecotoxicological and toxicological properties of test substances, in a standardised and globally accepted manner (in countries adherent to the OECD Mutual Acceptance of Data (MAD) system).

OECD TGs/GDs are being used for different purposes, but mainly for regulatory compliance i.e. the safety testing of chemicals and their subsequent chemical notification. Indeed, methods described in OECD TGs/GDs result from an evaluation and validation of their relevance, predictability and reliability/robustness, they are free to access and use (unlike other internationally technical standards which need to be purchased). Any data produced using OECD TGs/GDs following  Good Laboratory Practice(GLP) are covered by the MAD, a multilateral agreement in which participating countries are obliged to accept the data for use in regulatory compliance. This reduces the cost of testing and reduces the number of animals used in testing. Institutions that carry out the studies (generator of data) as well as evaluators of data who work mainly for industry or regulatory authorities are familiar with the use of OECD TGs/GDs.

To facilitate the use of data produced using OECD TGs/GDs, the OECD provides OECD Harmonised Templates (OHTs) that can help produce (robust) study summaries and store the data in data management systems (e.g. IUCLID). Most of these templates are built around OECD TGs, although they are generally only created after a new/amended TG has been published. As such they are not a formal part of TG development and TG developers are not necessarily involved. As they are generally intended to serve as standard formats for summarising data contained in any study report or publication related to particular endpoints, OHTs also exist for studies that were not conducted according to current guidelines. For nanomaterials, for instance, a range of OHTs (nrs 101-113) exists for physicochemical parameters for which no OECD TG is available.

The creation and revision of the OHTs is coordinated by the OECD Secretariat and supported by the OECD Expert Group on the OECD Harmonised Templates (OHT Expert Group). Experts are nominated by national authorities, industry and observer organisations interested in chemical test reporting issues and the interface between Test Guidelines and related databases. The draft new or revised templates undergo a thorough review process before their publication. After this process, the new or revised OHTs are published on the OECD Website.

 Extracted from the NanoHarmony Training Material – From science to standards and harmonised OECD Test Guidelines
‘Importance of standardised and harmonised test methods.’

OECD TGs/GDs are also being used to generate reliable data as relevance/ predictivity and reliability/robustness of the test methods are aspects that have been demonstrated in the validation process and thus do not need to be demonstrated each time the method is subsequently used. OECD TGs/GDs thus facilitate the comparison and reuse of results within the scientific community and foster the exchange of research activities and safety strategies between stakeholders of different institutional backgrounds (e.g. Academia, Industry, NGOs).

Theoretically, OECD TGs/GDs are applicable for testing chemicals, including materials. If limitations have been identified, these are described in the respective TG (applicability domain) or specific GDs (e.g. GD 23, Guidance Document on Aquatic Toxicity Testing of Difficult Substances and Mixtures, or GD 36, Guidance on Sample Preparation and Dosimetry for the Safety Testing of Manufactured Nanomaterials). With respect to the testing of nanomaterials, specific advice is compiled by OECD under the following link: Publications in the Series on the Safety of Manufactured Nanomaterials - OECD. You are also invited to watch the NanoHarmony Webinar on the use of OECD Test Guidelines for testing nanomaterials. 

NanoHarmony Webinar - Improving the OECD Test Guidelines Process: Using TGs

Revision of OECD Test Guidelines (TGs) and Guidance documents (GDs) 

OECD TGs and GDs can be updated to keep pace with progress in material science, alternative testing approaches and countries’ regulatory needs. For example, new developments may allow the reduction of animal numbers or animal suffering (i.e., consideration of the principle of the 3Rs) for an equal or more accurate prediction of human health and environmental hazards.  One should be aware that substitute tests, modifications of endpoints in existing tests, and enhancement of existing test methods need to be validated regardless of whether tests are for chemical properties, human health or environmental effects (See validation process page for details).

The revision of an OECD TG/GD can only be carried out by following the procedures in OECD, i.e. starting with drafting and submission of a Standard Project Submission Form. The OECD's working groups of the OECD Test Guidelines Programme, composed of experts from Member countries and relevant stakeholders, are responsible for discussing, reviewing, and updating the guidelines as needed. These working groups ensure that the guidelines remain scientifically up-to-date and address relevant safety and environmental concerns.

When the desirability of deleting existing TG(s) arises from a proposal to adopt new or updated TG(s), such deletion should be integrated into the proposal to adopt the new/updated TG(s) and be reviewed, approved and endorsed according to the same procedures described in this tool and in OECD GD1 (as revised in 2009). When a proposal to delete (an) existing TG is not related to a proposal to adopt a new or updated TGs, such a proposal should be supported by a valid argument. The Secretariat will distribute the proposal and rationale for deletion to the member countries for comment. The procedures for review, approval and endorsement of the deletion of existing TGs will be the same as those described in this tool and in OECD GD1 (as revised in 2009) for the development of new, or the updating of existing TGs.

• With regard to the use of OECD TGs/GDs, no processes are involved within the framework of the OECD Test Guidelines Programme. With regard to the revision of an OECD TG/GD, the details described in the various pages of this tool are valuable for both new and revised developments.

Stakeholders like industry, regulatory authorities as well as academic researchers and NGOs, using the TG/GDs on a regular basis, are invited to give feedback to the appropriate OECD contacts (e.g. national coordinators or BIAC or ICAPO representatives) on possible improvements of the TGs/GDs.

• Regularly check for updates: The OECD is constantly working on updating and improving TGs/GDs. Make sure to periodically check the OECD website or sign up for their newsletter to stay informed about any updates, new guidelines, or changes to existing guidelines. This will ensure that you are always using the most up-to-date and relevant methods. The work plan for the OECD Test Guidelines Programme informs on ongoing activities.

• Understand the scope and applicability of OECD TGs/GDs: Each OECD TG/GD is designed for a specific purpose and to address particular hazards or endpoints. Before using a TG/GD, make sure you understand its scope and applicability to ensure that it is suitable for the chemical or material you are testing (e.g. validation reports/supporting documents published along with the OECD TGs show the performance of the test methods).

• Training and expertise: Proper implementation of OECD TGs/GDs requires adequate training and expertise in the field of chemical testing. Ensure that the personnel conducting the tests are well-trained and familiar with the guidelines as well as with any relevant national or international chemical regulations. This ensures that the results of the tests are accurate and reliable and that the testing process is compliant with the regulatory requirements.