This may be a FAQ, but I can't remember it being one ...

Someone in my company came to me with a CAS Number and wanted to know its chemical name. Although we have a book of names and numbers it is only suitable for name to number (except in some lucky cases).

I assumed it would be trivial to find a way of doing it on the WWW - but although I found a couple of sites that offered such lookup as a free service (and my thanks go to them), their databases were too small and didn't have my particular CAS Number. They were focussed on giving the data on the chemicals, and putting all that data on all those chemicals would be a Herculean task.

But I'm not asking for a database which gives all the information on the chemical - all I want is CAS Number --> chemical name. I can do the rest myself.

What is the legal status of CAS Numbers? I'd assumed that they were public property for the good of us all. So I assumed it was possible for anyone to get hold of a copy of the code so we can put it on our computers and swap easily between name and number. A simple ASCII table would be all one needs - bringing it into a simple database package would be trivial.

Thanks

Steve Steven Abbott steven@abbott.demon.co.uk http://www.autotype.com

Nothing is ever that simple. The CAS Registry System is maintained by Chemical Abstracts Service, a subsidiary of the American Chemical Society, and they charge for their products for cost-recovery (and perhaps income/profit for themselves and ACS). CAS numbers may be freely used, but I am sure there is a threshold after which you may violate CAS copyright, e.g., if you systematically incorporated a large number of these into a database used for commercial purposes. There are various CAS nomenclature files on DIALOG, STN and other major commercial online services. Also, check out the CAS fee-based files on the net (http://casweb.cas.org/). A cheaper route, but with fewer total CAS Reg. Nos. in the database, would be to use the non-royalty chemical name database from the National Library of Medicine. Regarding name-number files being simple--no way. There are now millions of compounds with numbers and often multiple, complex names in the CAS Registry files--way too big to bother put online for desktop computers (and you'd have to purchase/license this from CAS). Ron Rader Biotech. Info. Inst. biotech@bioinfo.com http://www.bioinfo.com/biotech/ chemweb: A list for Chemical Applications of the Internet. Archived as: http://www.lists.ic.ac.uk/hypermail/chemweb/ To unsubscribe, send to majordomo@ic.ac.uk the following message; unsubscribe chemweb List coordinator, Henry Rzepa (rzepa@ic.ac.uk)