My organization is looking to replace our old a 40 cal arc flash suits. Currently all of our suits are of the 1-piece coverall design. For heat stress concerns, I am interested in replacing them with 2-piece jacket & pant style gear. However, a concern has been brought up regarding a possible "chimney effect" where the arc flash could rise up the jacket. I can find no such text anywhere supporting or refuting this concern. My thoughts were that if this were possible, there would not be NFPA 70E certified 2-piece arc flash suits. Has anyone ever run into this concern or have any information I can use to refute this?