by Steven A. Smith [SASMITH@MIDWAY.UCHICAGO.EDU]
For optional detail, white phosphorous fragments often cauterize themselves into wounds, putting themselves out. When the victim is opened up to surgically remove the fragment, the white phosphorous re-ignites, and can be propelled from the wound by the resultant steam created, creating a hazard for medical personnel as well as the victim. GM's discretion on how to play this. I'd consider it a rare event, resulting on an 8- per fragment which hits. Fragments which cauterize themselves cease doing burn damage and do not bleed.
My $.02. I've seen WP artillery rounds, and dummy grenades, but I've never had the opportunity to use one. The manuals are quite explicit about not being with 30 meters of one when it goes off, though. One more thing, WP is also colloquially referred to as Willie Pete.