RTEC RTECS Number

(a limit field)

ab1254000 in rtec

gb* in rtec

This is one of the fields contained within the Substance Identifiers and Basic Chemistry superfield (ZID) which itself is associated with the Substance Identifiers and Basic Chemistry message field (ID).

The RTECS (Registry of Toxic Effects of Chemical Substances) number is a unique identifier assigned by NIOSH (US National Institute of Occupational Safety and Health) to every chemical substance in the RTECS database. Each such substance is identified a by 9 character sequence of which the first 2 characters are alphabetic while the remainder are numeric.

Each identifier varies directly with the alphabetic sequence of the name, so that toluene, for example, has a higher number than benzene and the identifier is assigned alphabetically and numerically to each RTECS substance. It is not intentionally related to the compound's toxicity or structure, although compounds with alphabetically similar names and, in some cases therefore, similar structures are grouped together.

Thus, the second search example given above finds all compounds containing chromium whereas the first search reveals a single substance record, namely that for acenaphthylene. Using RTECS numbers (as with CAS numbers) is particularly useful in narrowing down a search.