Help for Searching Common Chemistry
You can quickly and easily confirm a chemical name, or CAS Registry Number® from this database of common, everyday chemicals.
You can search for substances in Common Chemistry in one of 2 ways:
- CAS Registry Number
- Chemical Name
CAS Registry Number Look Up
Type in a CAS Registry Number in the Registry Number search box.
A CAS Registry Number includes up to 10 digits which are separated into 3 groups by hyphens. The first part of the number, starting from the left, has up to 7 digits; the second part has 2 digits. The final part consists of a single check digit. The general format is xxxxxx-yy-z.
For example, 58-08-2 is the CAS Registry Number for caffeine.
If you type in a continous numeric string without hyphens, the application will insert hyphens at the expected positions and attempt a Registry Number look up.
A check digit algorithm helps to ensure you are using a mathematically valid CAS Registry Number. If you type in an invalid number you will receive an error message and be asked to try your search again.
Each CAS Registry Number (often referred to as a CAS Number):
- Is a unique numeric identifier
- Designates only one substance
- Has no chemical significance as a number
Since the CAS Registry Number is a unique substance identifier, when you search by Registry Number you are in effect doing a simple look up. The Registry Number will either be in the Common Chemistry database or it will not.
Fragment or substring searching is Not supported for Registry Number search.
Chemical Name Searching
Type in a chemical name or name fragment in the Chemical Name search box.
This can be a complete name such as "aspirin" or a name fragment such as "acetoxybenzoic". A name fragment will likely result in multiple search results, so it will help to be as precise as you can be.
In this example, at least one of the search results for "acetoxybenzoic" will be the record for aspirin since 2-acetoxybenzoic acid is a synonym for aspirin. Note that both chemical names map to the same CAS Registry Number!
To run an exact chemical name search, enter your search term in the Chemical Name text box and then select the Exact Chemical Name Match check box option.