<Tr> <Th> Inventory </Th> <Th> Scope </Th> <Th> Format </Th> <Th> No. of entries (if fixed No. of entries) </Th> </Tr> <Tr> <Td> European Inventory of Existing Commercial Chemical Substances (EINECS) </Td> <Td> Substances, excluding polymers, that were recorded as being commercially available in the EU from 1 January 1971 to 18 September 1981 . These were considered registered under Article 8 (1) of the Dangerous Substances Directive (67 / 548 / EEC). They are considered phase - in substances under the REACH Regulation . </Td> <Td> 2xx - xxx - x 3xx - xxx - x </Td> <Td> 100,102 </Td> </Tr> <Tr> <Td> European List of Notified Chemical Substances (ELINCS) </Td> <Td> Substances notified under the Dangerous Substances Directive Notification of New Substances (NONS) that became commercially available after 18 September 1981 . </Td> <Td> 4xx - xxx - x </Td> <Td> 4,381 </Td> </Tr> <Tr> <Td> No Longer Polymers (NLP) </Td> <Td> The definition of polymers was changed in April, 1992 with the result that substances previously considered to be polymers were no longer regarded as polymers . Consequently, a list, called the NLP - list (No Longer Polymer), was made of such substances that were not covered by the polymer definition but were placed on the market between after 18 September 1981 and 31 October 1993 . </Td> <Td> 5xx - xxx - x </Td> <Td> 703 </Td> </Tr>

What is a ec number for a chemical