توپ سیستم طبقه بندی آسیاب
SECTION-3 - NC State University. hazard ball mill vials used with reactive materials may not be opened by hand. It is listed under the category "known to be carcinogens " in the Annual Report on . perchlorates in ventilation system ductwork. Perchloric . Class 3B and 4 lasers can present a variety of hazards to both personnel operating the lasers.