White Phosphorus Libel
This slanderous accusation is false. In the past the international Red Cross has said that Israel has fired white phosphorus shells in its offensive in the Gaza Strip, but has no evidence to suggest it is being used improperly or illegally.
The comments came after a human-rights organization accused the Jewish state of using the incendiary agent, which ignites when it strikes the skin and burns straight through or until it is cut off from oxygen. It can cause horrific injuries.
The International Committee of the Red Cross urged Israel to exercise “extreme caution” in using the incendiary agent, which is used to illuminate targets at night or create a smoke screen for day attacks, said Peter Herby, the head of the organization’s mines-arms unit.
“In some of the strikes in Gaza it’s pretty clear that phosphorus was used,” Herby told The Associated Press. “But it’s not very unusual to use phosphorus to create smoke or illuminate a target.
We have no evidence to suggest it’s being used in any other way.
“In response, the Israeli military said Tuesday that it “wishes to reiterate that it uses weapons in compliance with international law, while strictly observing that they be used in accordance with the type of combat and its characteristics.”Herby said that using phosphorus to illuminate a target or create smoke is legitimate under international law, and that there was no evidence the Jewish state was intentionally using phosphorus in a questionable way, such as burning down buildings or consciously putting civilians at risk

Hamas using white phosphorus on humans on purpose.
https://www.ynetnews.com/articles/0,7340,L-4169835,00.html
white phosphorus is legal if used to illuminate.
“uses of white phosphorus, such as illuminating a battlefield, are not prohibited.”
https://www.who.int/news-room/fact-sheets/detail/white-phosphorus