1. a) CAS numbers refer to the Chemical Abstracts Registry numbers assigned to specific chemicals, isomers or mixtures of chemicals. Some isomers or mixtures that are covered by the standards do not have CAS numbers assigned to them. The standards apply to all of the chemicals listed, whether CAS numbers have been assigned or not.
2. b) No CAS number(s) have been assigned to this chemical, to its isomers, or mixtures containing these chemicals.
3. c) CAS numbers for some of the isomers are listed: the standards apply to all of the isomers and mixtures even if CAS numbers have not been assigned.

(Source: Amended at 13 Ill. Reg. 10893, effective June 27, 1989)