The OECD Harmonised Templates (OHTs) are standard data formats for reporting information used for the risk assessment of chemicals, mainly studies done on chemicals to determine their properties or effects on human health and the environment, but also for storing data on use and exposure. They are aimed at developers of database systems, as they prescribe the formats by which information can be entered into and maintained in a database. By using these templates, governments and industry are easily able to electronically exchange test study summary information.

The templates can be used to report summary test results for any type of chemical (e.g., pesticides, biocides, industrial chemicals, food/feed additives). The OECD Harmonised Templates cover endpoints and reporting elements which are grouped as follows:

Physico-chemical properties (incl. nanomaterials) - OHTs 1 to 23-5 & 101 to 113
Environmental fate and behaviour  - OHTs 24 to 40 & 401
Effects on biotic systems - OHTs 41 to 57
Health effects - OHTs 58 to 84 & 86
Pesticide residue chemistry - OHTs 85-1 to 85-10
Analytical methods - OHT 87
Efficacy - OHTs 88 & 89
Emissions from treated articles - OHT 90
Intermediate effects - OHT 201
Use and exposure information - OHTs 301 to 306
Generic elements for all OHTs

- Literature reference - Test material information                        - Reference substance - Chemical inventory

Harmonised endpoint summaries

- Physico-chemical properties (including nanomaterials)  - Environmental fate - Effects on biotic systems - Analytical methods - Health effects

Each Template is accessible online in readable format (.doc file), with associated html schema (.xsd file), and with predefined tables and executive summaries (.html files) as available. The links to corresponding OECD Test Guidelines are given where applicable. 

All OHT materials can also be downloaded at once from a single zip file which collates the 133 OECD Harmonised Templates, the 105 Harmonised endpoint summaries, and their related materials. 

For more information and technical details on Templates see: IntroductionFormat and conventions used.



NEW OHTs No. 50-3, No. 50-4, No. 50-5, and No. 75-2, 105 harmonised endpoint summaries, and format changes related to IUCLID 6v7 release now available online (July 2023)

Four new OHTs have been developed and are now available online. OHT 50-2 'Toxicity to terrestrial arthropods' has been split into three new templates to better accommodate the reporting needs of these type of studies: (1) OHT 50-3 'Toxicity to bees', (2) OHT 50-4 'Toxicity to terrestrial arthropods other than bees' and (3) OHT 50-5 'Toxicity to soil arthropods'. NEW OHT 75-2 ‘Endocrine disrupter screening- In vitro’ has been developed to report endocrine disrupter screening test guidelines. Also, 105 harmonised endpoint summary formats are now part of the OHTs suite.
In addition, updates to all OHTs have been introduced related to the standard maintenance of the format based on IUCLID users' feedback and the necessary improvements to regulatory data collection and processes (e.g., for the EU Biocidal Products Regulation (BPR), EU REACH, or the EU Regulation on the Classification, Labelling and Packaging of substances and mixtures (CLP).