(a) A proprietary solvent is any article made with any other ingredients combined with the ingredients in the minimum ratios prescribed in this section. A proprietary solvent shall be made with S.D.A. Formula No. 1 or 3-A containing, for every 100 parts (by volume) of alcohol:
(1) No less than 1 part (by volume) of one or any combination of the following: gasoline, unleaded gasoline, heptane, or rubber hydrocarbon solvent, and
(2) No less than 3 parts (by volume) of one or any combination of the following: ethyl acetate (equivalent to 85% ester content, as defined in Sec. 21.106 of this chapter), methyl isobutyl ketone, methyl n-butyl ketone, tert-butyl alcohol, sec-butyl alcohol, nitropropane (mixed isomers), ethylene glycol monoethyl ether, or toluene.
(b) If this article contains more than 4% by weight of methyl alcohol, the label shall have a skull and crossed bones symbol and the following words: ``danger,'' ``poison,'' ``vapor harmful,'' ``May be fatal or cause blindness if swallowed,'' and ``Cannot be made nonpoisonous.''