Are you referring to tungsten-halogen (incandescent element) or metal halide (high intensity arc discharge)? I have investigated two warehouse fires ignited by exploding arc tubes in HID lamps. A photograph of one of the lamps is at page 191 of Kirk's 6th edition. I have never seen a fire started by an exploding tungsten-halogen lamp, but seen them ignite draperies.
Mike Learmonth, B.A.Sc., M.B.A., M.Eng., J.D., LL.B., C.F.E.I., P.Eng.
Senior Associate, Giffin Koerth Forensic Engineering
Michael A. Learmonth, B.A.Sc., M.B.A., M.Eng., J.D., LL.B., C.F.E.I., P.Eng.
Senior Associate,
Giffin Koerth Forensic Engineering and Science
40 University Avenue, Suite 800
Toronto, Ontario, Canada M5J 1T1
Phone: 416-368-1700 ext. 225
Fax: 416-368-5576