Section 111670 shall not apply to coal tar hair dye, that is conspicuously labeled as follows:
"Caution-this product contains ingredients that may cause skin irritation on certain individuals and a preliminary test according to accompanying directions should first be made. This product must not be used for dyeing the eyelashes or eyebrows; to do so may cause blindness."
The labeling shall also bear adequate directions for such preliminary testing.
Ca. Health and Saf. Code § 111675