Upon offering employment to a prospective employee, each employer shall inform the prospective employee of any chemicals, toxic substances, radioactive materials or any other substances which he uses or produces in the manufacture of any item, product or material, or which he uses or produces for purposes of research, experimentation or treatment, which the employer should have reasonable cause to believe will cause birth defects or constitute a hazard to an individual’s reproductive system or to a fetus when the individual is exposed to any of such substances in the course of his job assignment. Such information shall be made available to current employees who are exposed to such hazards.