A chemical directory can come in one of two different flavors, technical and commercial.

Technically Oriented Chemical Directories

This kind of chemical directory allows finding a chemical by its molecular formula, common name, or other technical specification. It is a directory for those with technical familiarity of chemicals.

Once you specify a name, formula etc. the directory takes you to a page that lists the chemicals meeting the search criteria. Against each, supplier names are also given. You can then get more details of a particular supplier, or a particular chemical.

Links would also be available for getting an offer from a particular supplier for a chemical.

Such a technically oriented chemical directories would typically have other technical features, such as chemical calculators that calculates different properties such as molecular mass from a formula or other information.

Another valuable technical feature is a property explorer that calculates drug-relevant properties from valid chemical structures. This helps identify high-risk side effects of the structure. You can identify toxicity for example.

Commercially Oriented Chemical Directories

This kind of directory lists suppliers of particular chemicals in the conventional manner. For example, you can find suppliers for absorbents, acids and so on in alphabetical order. Some directories might also allow you to find suppliers in different countries.

Forwarding a request for quotation - RFQ - to suppliers is a facility that a chemical directory might offer. At least one directory allows you to send enquiries wholesale to many suppliers with just one RFQ form. You can select the companies you want the RFQ to be sent.

There are also chemical suppliers databases in print and computer readable media formats. You can buy these databases against payment. Alternatively, you might pay a monthly or such fee and access their online databases.

While some directories charge the buyers to access their databases of suppliers, others might allow free access to buyers and charge sellers for including their information. In the latter case, only those sellers who pay for inclusion might be included in the directory, i.e., it would be a less comprehensive directory than the other kind.

Regional Chemical Directories

Regional chemical directories seek to promote the chemical industries of different regions. It would also help buyers to find sources near them, or low cost suppliers from all over the world. For examples, lower cost manufacturers in, say, India and China can supply chemicals that meet specifications at lower costs.

Conclusion

The chemical industry is discovering new formulations continuously. The chemicals have different properties and effects. Many might be drugs that can have side effects along with specific curative properties.

To serve users in this industry, chemical directories need to incorporate some unique features. Thus you can find directories where you can search for chemicals by their molecular formula or CAS number, as well as by name.

The technically oriented directories might also provide chemical calculators and details of reactions based on the chemical structure.

Then there is the conventional chemical directory where you find suppliers for each kind of chemical, whom you can contact directly or through the directory publishers.