chemBlink Search Help

Search for chemicals by product name, CAS Registry Number, or molecular formula. Use the separate Supplier search to find companies. The same name-search tips also apply to Safety Data Sheets (SDS).

1. Product Name

Enter a complete chemical name or a known synonym. Names are not case-sensitive, and differences in spaces, hyphens, and most punctuation are ignored in the regular name search.

For example, ethyl alcohol and ethyl-alcohol are treated alike. You may search in English or Chinese.

Looking for part of a name? The regular search matches indexed names, not arbitrary words within a longer name. If the desired chemical is missing, click Extended Search on the results page. This searches for the text anywhere within stored names and synonyms:

• hydrochloric can find hydrochloric acid.
• Prussian can find Prussian Blue.

Extended Search may take several seconds. It is optional and is available when the regular name search finds no results or displays a list of matches. It is also available for SDS name searches.

2. CAS Registry Number

Enter the complete CAS number, including both hyphens, for example 64-17-5. The number must have a valid format and check digit.

Partial CAS numbers such as 17-5 are not supported. Some alternative CAS numbers may be found through existing CAS mappings, but CAS searches do not use partial or fuzzy matching.

3. Molecular Formula

Enter a molecular formula using correctly capitalized element symbols and numbers, for example H2O, C6H12O6, or NaCl. Element order does not matter: the search standardizes elemental composition before matching.

For more complex substances, formulas may include parentheses and dot-separated components, such as CuSO4.5(H2O). Supported repeating units may include a variable suffix, for example (C4H8O)n.

Coefficients apply only to the immediately following element or parenthesized group. For example, 3(H2O) means three water units (H6O3), while 3H2O means six hydrogen atoms and one oxygen atom (H6O). Use parentheses whenever a coefficient applies to an entire group.

Use a comma (European decimal separator) for non-integer numbers in formulas. A period (.) separates formula components, so write 1,5(H2O), not 1.5(H2O).

Formula searches use exact matches of standardized compositions or indexed formula components, not partial text matching. Entering only part of a formula does not automatically find every formula containing those characters.

4. Supplier

Select the Supplier search and enter all or part of a company name or website domain, such as sigma. Supplier searches are separate from chemical product searches and allow partial matches.

Tip: For the fastest results, start with a complete CAS number, molecular formula, or chemical name. Use Extended Search only when a name search does not show the chemical you need.