"Grade designations for glass epoxy laminates are: G10, G11, FR4 and FR5. Of these FR4 is the grade most widely in use today. G-10, the predecessor to FR-4, lacks FR-4's self-extinguishing flammability characteristics."
Donc non, le FR4 serait du G10 ininflammable et le FR5 (comme "flam resistant" ?) serait du G11 ininflammable :
http://www.liren01.com/ProductShow.asp?ArticleID=201Et d'après eux :
http://www.boedeker.com/ilamg_p.htm, la différence entre G10 et G11 serait : "G-10 is slightly stronger while G-11 is a better insulator and can take higher temperatures."