IUPAC Standards Online

FREE ACCESS 2025

Secure your free access to IUPAC Standards Online until December 31, 2025 by going to https://www.degruyter.com/accessLink/IUPACor2025 for activation. You will need a user account on degruyterbrill.com to access the Online Resource; you will then have free access to all articles until the end of the year.

IUPAC Standards Online contains the IUPAC standards and recommendations taken from the journal Pure and Applied Chemistry (PAC). The International Union of Pure and Applied Chemistry (IUPAC) is responsible for establishing chemical standards that are binding at the international level for industry and academia, patent attorneys, toxicologists, environmental scientists, legislation, etc. These standards include definitions for terms, standard values, procedures, rules for the designation of substances and materials, names and properties of elements in the periodic table, and many more. This Online Resource is the only way to quickly and easily search and retrieve IUPAC standards and recommendations. Previously, this information was only available unclassified in the extensive archive of Pure and Applied Chemistry.

The current issue of Pure and Applied Chemistry can be found here.

IUPAC and De Gruyter

In addition to the IUPAC Standards Online Resource, De Gruyter is proud to co-publish with IUPAC the Society's monthly journal, Pure and Applied Chemistry, as well as the Society's quarterly news magazine, Chemistry International, and the new open access journal Chemistry Teacher International. Links to all IUPAC content available on De Gruyter Online can be found on the IUPAC & De Gruyter Home Page, as along with special content such as themed virtual issues collated from different journals and volumes.

• Practical: IUPAC standards and recommendations are easy to find
• Comprehensive: standard values and procedures, nomenclature, terminology and symbols of chemistry and materials, properties of elements, etc.
• Intelligent: thematic structure, advanced search, cross-linked entries
• The interactive periodic table of elements provides specific information on each element
• The InChI search offers targeted retrieval of information on specific chemical compounds
• No restrictions on digital rights management - unlimited number of simultaneous users at each university / institution

Here you will find instructions for searching in the IUPAC Standards Online and explanations of the individual search functions.

Search

You have two different options for searching.

Search form

The search form allows you to search using various search criteria. To do so, select the appropriate criterion in the search field and enter your search term(s) in the search field. The following search criteria are available:

1. Full Text: Searches in all entries for the entered terms. Finds all entries that contain all searched terms and therefore returns the most results. For a more specific search, the other search criteria are more suitable.
   
   The following operators can be used in the search field:
• *: Added to a string. Searches for entries including all terms that match the searched string with any addition.
• AND: Searches for entries including all the terms connected by this operator (default search function).
• OR: Searches for entries including at least one of the terms connected by this operator.
• NOT: Searches for entries including the first, but not the second of the terms connected by this operator.

These operators can be combined with each other.

2. Title: Finds all entries whose titles contain all searched terms. This search criterion can be used to search specifically for entries for particular terms. Search with truncation does not work at the moment.
3. Author: Finds all entries with authors of the searched name. Suggests up to 15 matching author names in alphabetical order as you type. This search criterion can be used to search for entries by specific authors.
4. Keyword: Finds all entries to which the searched keyword is assigned. Suggests up to 15 matching keywords in alphabetical order as you type. This search criterion can be used to search for entries that deal with a specific topic or element.
5. Type: Select a type from the drop-down menu: Article, Chemical Compound, Definition, Recommendation, Technical Report. Finds all entries of this type.
6. Publication Year: Select Exact to search for a single year, or Range to search for a range of years. Finds all entries that have been published electronically in this year or range of years.
7. Bibliography: Finds all entries whose bibliography contains all searched terms. This search criterion can be used to search for specific sources or their titles, authors, etc.
8. Element: Finds all entries that contain the searched chemical element. Suggests up to 15 matching elements in alphabetical order as you type. This search criterion can be used to search for entries in which a particular element is mentioned.
9. Entry language: Select a language from the drop-down menu. Finds all entries which are written in this language. Only english language is available for IUPAC.

Please note: The search is not case sensitive.

You have the option to apply several search criteria at the same time. To do this, click on "Add row" in the search form. This creates a second search field in which you can set another search criterion (or else the same one). You can create as many additional search fields as you like.
If you use more than one search field, the search will find all entries that match all search criteria ("Search for all of these terms"). Instead, you can also select "Search for any of these terms" above the search fields, which will cause the search to find all entries that match at least one of the searched criteria.
By clicking on "Add NOT" you create a search field to which you can assign a search criterion. Terms entered in this search field will be excluded from the search. You can add this search field as often as you like.
By combining the above functions, you are able to perform very specific searches.

Example

You want to search the IUPAC Standards Online for all entries that mention the word "DNA" and were published between 2019 and 2023. However, you want to exclude entries of the type "Technical Report" from the search. For this you use the search form as follows:

1. Create a second search field via "Add row".
2. Select the search for "all of these terms" (default option).
3. In the first search field, select the search criterion Full Text and enter the search term "DNA".
4. In the second search field, select the search criterion Publication Year, click on "Range" and enter "2019" and "2023" in the two search fields.
5. Create a third search field via "Add NOT". This is marked with a "NOT".
6. Select the search criterion Type in this search field and select “Technical Report” in the dropdown menu of the search field.
7. After clicking on "Search" you will see 10 out of 86 hits in the results list.

Browse

The browse button allows you to quickly search for scientific disciplines. The results list of a browse search can be further searched via the search form as described above.

Results list

The results that match your search are listed on one or more pages. The number of search results as well as the search criteria can be found above the results list.

Each search result consists of the title of the entry, author(s) if existent, access information, entry type, online publication date (print publication date in brackets, if applicable), the cover of the online resource as well as a button to download the PDF ("Download PDF"), if available, and a text preview showing relevant text passages and highlighting the searched term in yellow (only for Full Text search criterion).

You can access a search result by clicking on the title or cover of the online publication. If you do not have access to the database, please log in first.

The search results are sorted by relevancy (frequency and weighting of the searched terms). You can also sort by date ("New to old" or "Old to new") or by title ("A to Z" or "Z to A").
Furthermore, instead of the default 10 results per page, you can also display 20, 50 or 100 results per page.

The search results can be further restricted under "Filter Results". Various filter options are available for this:

1. Access: This option filters the search results according to who can access them. By default, "All content" is found. It is possible to filter by "Licensed content", "Open Access", "Publicly available" as well as "All available content".
2. Publication
3. Type
4. Publication Year
5. Element
6. Entry language

All filters can be combined with each other. Filtering by certain filter options excludes further certain filter options if there are no entries which match both options.