(a) An employer may provide the information required by Section 8 with respect to an entire mixture, considered as a whole, instead of with respect to each toxic substance contained in such mixture, provided that:
     (1) Toxicity testing information exists on the entire mixture or adequate information exists to form a valid judgment of the hazardous properties of the entire mixture; and
     (2) Provision of information on the entire mixture will be as effective in protecting employee health as the provision of information on each toxic substance contained in the mixture.
     (b) This Section shall become effective with respect to any toxic substance upon filing, unless a later effective date is specified in the rule, pursuant to Section 4(e).