( CNN ) -- Israel pledged to limit the use of munitions containing white phosphorus and make greater efforts to protect civilians during conflicts , in a report this week to the United Nations . The Israeli military was roundly criticized for firing white phosphorus shells over densely populated areas during the Gaza offensive that began in late 2008 . White phosphorus ignites and burns , creating white smoke when it is exposed to oxygen . Militaries use it as a smoke screen to protect troops during combat . If it comes in contact with skin , white phosphorus creates an intense and persistent burn . In making the changes , Israel said it had done nothing wrong . `` The use of smoke-screening munitions containing phosphorus during the Gaza operation ... was consistent with Israel 's obligations under the Law of Armed Conflict , '' Israel said in the report . Yet , as a result of `` the lessons learned '' in the aftermath of the Gaza offensive , the report said the Israeli military `` is in the process of establishing permanent restrictions on the use of munitions containing white phosphorus in urban areas . '' In a report entitled `` Rain of Fire : Israel 's Unlawful Use of White Phosphorus in Gaza '' released last year , Human Rights Watch said Israel 's firing of white phosphorus shells over densely populated areas during the Gaza offensive `` was indiscriminate and is evidence of war crimes . '' `` In Gaza , the Israeli military did n't just use white phosphorus in open areas as a screen for its troops , '' said Fred Abrahams , a senior emergencies researcher for Human Rights Watch . `` It fired white phosphorus repeatedly over densely populated areas , even when its troops were n't in the area and safer smoke shells were available . As a result , civilians needlessly suffered and died . '' The offensive , called Operation Cast Lead , was launched December 27 , 2008 and ended January 17 , 2009 with a ceasefire . Of the 1,453 people estimated killed in the conflict , 1,440 were Palestinian , including 431 children and 114 women , a U.N. report said . The 13 Israelis killed included three civilians and six soldiers killed by Hamas , and four soldiers killed by friendly fire , it said .
White phosphorus is used to create smoke screen for troops . The element burns when exposed to oxygen and creates an intense burn when it touches the skin . It's also a very effective weapon against tanks, aircraft carriers, ships, etc...