White phosphorus White phosphorus is a material made from a common allotrope of the chemical element phosphorus that is used in smoke , tracer , illumination and incendiary munitions . Other common names include WP , and the slang term " Willie Pete , " which is dated from its use in Vietnam , and is still sometimes used in military jargon . As an incendiary weapon , white phosphorus burns fiercely and can ignite cloth , fuel , ammunition and other combustibles . In addition to its offensive capabilities , white phosphorus is also a highly efficient smoke - producing agent , burning quickly and producing an instant blanket of smoke . As a result , smoke - producing white phosphorus munitions are very common , particularly as smoke grenades for infantry , loaded in grenade launchers on tanks and other armored vehicles , or as part of the ammunition allotment for artillery or mortars . These create smoke screen s to mask movement , position or the origin of fire from the enemy . White phosphorus is used in bomb s , artillery , mortars , and short - range missile s which burst into burning flakes of phosphorus upon impact . History . White phosphorus is believed to have been first used by Fenian arsonists in the 19th century in the form of a solution in carbon disulfide . When the carbon disulfide evaporated , the phosphorus would burst into flames , and probably also ignite the highly flammable carbon disulfide fumes . This mixture was known as " Fenian fire " and allegedly was used by disgruntled itinerant workers in Australia to cause delayed destruction of shabby sleeping quarters . In 1916 , during an intense struggle over conscription for the First World War , twelve members of the Industrial Workers of the World , a workers union opposed to conscription , were arrested and convicted for using or plotting to use incendiary materials , including phosphorus . It is believed that eight or nine men in this group , known as the Sydney Twelve , had been framed by the police . Most were released in 1920 after an inquiry . World War I , the inter - war period and World War II . The British Army introduced the first factory - built WP grenades in late 1916 . During World War II , white phosphorus mortar bombs , shells , rockets and grenades were used extensively by American , Commonwealth , and , to a lesser extent , Japanese forces , in both smoke - generating and antipersonnel roles . The British military also used white phosphorus bombs against Kurdish villagers and Al - Habbaniyah in Al - Anbar province during the Great Iraqi Revolution of 1920 . In the interwar years , the U . S . Army trained using white phosphorus , by artillery shell and air bombardment . In 1940 , when the invasion of Britain seemed imminent , the phosphorus firm of Albright and Wilson suggested that the British government use a material similar to Fenian fire in several expedient incendiary weapons . The only one fielded was the " Grenade , No . 76 " or " Special Incendiary Phosphorus grenade " , which consisted of a glass bottle filled with a mixture similar to Fenian fire , plus some latex ( see also Molotov cocktail , Greek fire ) . It came in two versions , one with a red cap intended to be thrown by hand , and a slightly stronger bottle with a green cap , intended to be launched from the Northover projector ( a crude 2 . 5 - inch black - powder grenade launcher ) . These were improvised anti - tank weapons , hastily fielded in 1940 when the British were awaiting a German invasion after losing the bulk of their modern armaments in the Dunkirk evacuation . Instructions on each crate of SIP grenades included the observations , among other things : These weapons were generally regarded as presenting a danger to their own operators and were never deployed in combat . At the start of the Normandy campaign , 20 % of American 81 mm mortar rounds were white phosphorus . At least five American Medal of Honor citations mention their recipients using white phosphorus grenades to clear enemy positions , and in the 1944 liberation of Cherbourg alone , a single U . S . mortar battalion , the 87th , fired 11 , 899 white phosphorus rounds into the city . The U . S . Army and Marines used white phosphorus shells in 107 - mm ( 4 . 2 inch ) mortars . White phosphorus was widely credited by Allied soldiers for breaking up German infantry attacks and creating havoc among enemy troop concentrations during the latter part of the war . Incendiary bombs were used extensively by the German , British and U . S . air forces against civilian populations and targets of military significance in civilian areas , including London , Hamburg , and Dresden . Late in the war , some of these bombs used white phosphorus ( about 1 – 200 grams ) in place of magnesium as the igniter for their flammable mixtures . The use of incendiary weapons against civilians was banned by signatory countries in the 1980 Convention on Certain Conventional Weapons Protocol III . The USA signed Protocols I and II on 24 March 1995 under the Clinton Administration ( and the amended article II on 24 May 1999 ) and later Protocols III , IV , and V , on 21 January 2009 under the Obama Administration . Later uses . White phosphorus munitions were used extensively in Korea , Vietnam and later by Russian forces in Chechnya . White phosphorus grenades were especially valued in Vietnam for destroying Viet Cong tunnel complexes as they would burn up all oxygen and suffocate the enemy soldiers sheltering inside . British soldiers also made extensive use of phosphorus grenades during the Falklands conflict to destroy Argentine positions as the peaty soil they were constructed from tended to lessen the impact of fragmentation grenades According to GlobalSecurity . org , during the December 1994 battle for Grozny in Chechnya , every fourth or fifth Russian artillery or mortar round fired was a smoke or white phosphorus round . In Iraq , the Saddam Hussein regime used white phosphorus , as well as chemical weapons that are scheduled in the Chemical Weapons Convention , in the Halabja poison gas attack during the Iran – Iraq War in 1988 , according to the ANSA news agency . Another news report said " US intelligence " called WP a chemical weapon in a declassified Pentagon report from February 1991 : Use in Iraq ( 2004 ) . In April 2004 , during the First Battle of Fallujah , a reporter from the North County Times described U . S . Marine mortar teams using a mixture of white phosphorus and high explosives to shell a cluster of buildings where Iraqi insurgents had been spotted throughout the week . In November 2004 , during the Second Battle of Fallujah , " Washington Post " embedded reporters stated that some U . S . artillery guns fired white phosphorus rounds that " create a screen of fire that cannot be extinguished with water . " Insurgents reported being attacked with a substance that melted their skin , a reaction consistent with white phosphorus burns . On November 9 , 2005 the Italian state - run broadcaster Radiotelevisione Italiana S . p . A . aired a documentary titled " Fallujah , The Hidden Massacre " , alleging that the United States ' used white phosphorus as a weapon in Fallujah causing insurgents and civilians to be killed or injured by chemical burns . The filmmakers further claimed that the United States used incendiary MK - 77 bombs in violation of Protocol III of the 1980 Convention on Certain Conventional Weapons . According to the Organization for the Prohibition of Chemical Weapons , quoted in the documentary , white phosphorus is permitted for use as an illumination device and as a weapon with regard to heat energy , but not permitted as an offensive weapon with regard to its toxic chemical properties . On November 15 , 2005 , the U . S . Department of Defense confirmed to the BBC that white phosphorus had been used as an incendiary antipersonnel weapon in Fallujah , stating " When you have enemy forces that are in covered positions that your high explosive artillery rounds are not having an impact on and you wish to get them out of those positions , one technique is to fire a white phosphorus round into the position because the combined effects of the fire and smoke - and in some case the terror brought about by the explosion on the ground - will drive them out of the holes so that you can kill them with high explosives . " Israel - Lebanon conflict ( 2006 ) . During the 2006 Israel - Lebanon conflict , Israel admitted that it had used phosphorus shells " against military targets in open ground " in south Lebanon . Israel clarified that its use of the white phosphorus bombs was permitted under international conventions . President of Lebanon Émile Lahoud claimed that phosphorus shells were used against civilians in Lebanon . The first Lebanese official complaint about the use of phosphorus came from Information Minister Ghazi Aridi . Ukraine white phosphorus train disaster . On 16 July 2007 , a train transporting 15 tanks containing white phosphorus derailed in the Lviv oblast . As a result 90 square kilometers were contaminated with a cloud of white phosphorus . In the first days 152 people were hospitalized . The disaster was described as an equivalent to the Chernobyl disaster . 16 , 000 people were checked for symptoms of chemical poisoning within a week , and Lviv residents were advised to stay inside and not to use water from wells , nor eat vegetables from their gardens or drink milk from their cows ( later this advice was revoked ) . On 18 July 2007 , it was reported that NATO was watching the toxic cloud movement . Gaza War ( 2008 – 2009 ) . In its early statements the Israeli military repeatedly denied using white phosphorus , saying " We categorically deny the use of white phosphorus " , and " The IDF acts only in accordance with what is permitted by international law and does not use white phosphorus . " It eventually admitted its use and stopped using the shells , however , saying that a " media buzz " led to its decision to do so . Numerous reports from human right groups during the war indicated that white phosphorus shells were being used by Israel in populated areas . Human Rights Watch said shells exploded over populated civilian areas , including a crowded Palestinian refugee camp and a United Nations school where civilians were seeking refuge . Additionally , Human Rights Watch said that white phosphorus injuries were suspected in the cases of ten burn victims . The International Red Cross stated that phosphorus weapons had been used in the conflict but would not comment publicly on the legality of Israel ’ s use of the weapon , pending further investigation , contrary to what had been attributed to the ICRC in a number of media reports . Human Rights Watch said its experts in the region had witnessed the use of white phosphorus . Kenneth Roth , the organisation ' s executive director , added : " This is a chemical compound that burns structures and burns people . It should not be used in populated areas . " Amnesty International said a fact - finding team found " indisputable evidence of the widespread use of white phosphorus " in crowded civilian residential areas of Gaza City and elsewhere in the territory . Donatella Rovera , the head of an Amnesty fact - finding mission to southern Israel and Gaza , said : " Israeli forces used white phosphorus and other weapons supplied by the USA to carry out serious violations of international humanitarian law , including war crimes . " On 5 January the Times reported that telltale smoke associated with white phosphorus had been seen in areas of a shelling . On 12 January it was reported that more than 50 phosphorus burns victims were in Nasser Hospital . On 16 January the UNRWA headquarters was hit with phosphorus munitions . As a result of the hit , the compound was set ablaze . Many other observers , including Human Rights Watch military experts , reported seeing white phosphorus air bursts over Gaza City and the Jabalya refugee camp . The BBC published a photograph of two shells exploding over a densely populated area on 11 January . Since Protocol III , of the Convention on Certain Conventional Weapons regulates Incendiary Weapons , and shells containing White Phosphorus , may be legal even in populated areas , more information is required to determine the legality of any shell landing in populated areas . The IDF stated on 13 January 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 . " On 14 January , Israeli news sources " Haaretz " and " Ynetnews " reported that a mortar shell containing white phosphorus was fired from Gaza and exploded without damage or injury in an open space in the Eshkol area . The official foreign press spokesman for the Israeli Police , Micky Rosenfeld , stated that the shell had landed in a field near Sderot . A day after the attack , a researcher for Human Rights Watch travelled to Sderot to investigate the claim . One resident said he had heard about a mortar shell , possibly with white phosphorus , landing in a field outside of town but could not specify where . When pressed for information , Rosenfeld could give no further insight , telling Human Rights Watch that " all I have is what ' s in the press release . " Local authorities in Sderot also told the researcher that they were unaware of the attack . On 15 January , the United Nations compound , housing numerous refugees in Gaza City , was struck by Israeli white phosphorus artillery shells , setting fire to pallets of relief materials and igniting several large fuel storage tanks . A UN spokesperson indicated that there were difficulties in attempting to extinguish the fires because of the white phosphorus and stated " You can ’ t put it [ white phosphorus ] out with traditional methods such as fire extinguishers . You need sand but we do not have any sand in the compound . " Senior Israeli defense officials maintain that the shelling using white phosphorus munitions was in response to Israeli military personnel being fired upon by Hamas fighters who were in proximity to the UN headquarters , and was used for smoke . The Israeli army investigated improper use of WP in the conflict , particularly in one incident in which 20 WP shells were fired in a built - up area of Beit Lahiya . On 17 January , Peter Herby , head of the International Committee of the Red Cross Arms Unit , confirmed the use of white phosphorus weapons by Israel in Gaza , outlined the rules applicable to phosphorus weapons and explained the ICRC ' s approach to the issue . On 20 January , Paul Wood of the BBC reports from Gaza on white phosphorus use in civilian areas . Amnesty team weapon expert Christopher Cobb - Smith , who witnessed the shelling by the IDF during the conflict , reported " we saw streets and alleyways littered with evidence of the use of white phosphorus , including still - burning wedges and the remnants of the shells and canisters fired by the Israeli army . " On 26 January , after weeks of fighting in which Israel either strenuously denied it was using white phosphorus weaponry , or insisted any use was " in line with international law " , the nation ' s Ministry of Defence admitted using white phosphorus in densely populated Gaza . On 25 March 2009 , USA Based Human Rights Organization Human Rights Watch published a 71 - page report titled Rain of Fire , " Israel ’ s Unlawful Use of White Phosphorus in Gaza " and said that Israel ' s usage of the weapon was illegal . White phosphorus munitions did not kill the most civilians in Gaza – many more died from missiles , bombs , heavy artillery , tank shells , and small arms fire – but their use in densely populated neighborhoods , including downtown Gaza City , violated international humanitarian law ( the laws of war ) , which requires taking all feasible precautions to avoid civilian harm and prohibits indiscriminate attacks . The Israeli government released a report in July 2009 that confirmed that the IDF used white phosphorus in both exploding munitions and smoke projectiles . The report acknowledged the use of exploding munitions by Israeli ground and naval forces . The report argues that the use of these munitions was limited to unpopulated areas for marking and signaling and not as an anti - personnel weapon . The Israeli government report further stated that smoke screening projectiles were the majority of the munitions containing white phosphorus employed by the IDF and that these were very effective in that role . The report states that at no time did IDF forces have the objective of inflicting any harm on the civilian population . Head of the UN Fact Finding Mission Justice Richard Goldstone presented the report of the Mission to the Human Rights Council in Geneva on 29 September 2009 , urging the Council and the international community as a whole to put an end to impunity for violations of international law in Israel and the Occupied Palestinian Territory . The Goldstone report accepted that white phosphorus is not illegal under international law but did find that the Israelis were " systematically reckless in determining its use in build - up areas " . It also called for serious consideration to be given to the banning of its use as an obscurant . Human Rights Watch claimed in its report that instead of white phosphorus , the Israeli military had a non - lethal alternative at its disposal - smoke shells produced by Israel Military Industries . In 2010 , Anchel Pfeffer of Haaretz claimed that the Israeli report to the UN included a section discussing two senior Israeli officers who were responsible for firing white phosphorus artillery shells on a United Nations compound and were reprimanded earlier that year . This was later disproved . The officers were reprimanded for permitting artillery shot in that same combat , and Israel continued to claim that its use of phosphorus in that combat was only for smoke . Afghanistan ( 2009 ) . There are confirmed cases of white phosphorus burns on bodies of civilians wounded in Afghanistan US - Taliban clashes near Bagram . The United States has accused Taliban militants of using white phosphorus weapons illegally on at least 44 occasions . In May 2009 , Colonel Gregory Julian , a spokesman for General David McKiernan , the overall commander of U . S . and NATO forces in Afghanistan , confirmed that Western military forces in Afghanistan use white phosphorus in order to illuminate targets or as an incendiary to destroy bunkers and enemy equipment . The Afghan government later launched an investigation into the use of white phosphorus munitions . Use in Yemen ( 2009 ) . Houthi fighters in Yemen claimed Saudi warplanes dropped phosphorus bombs on villages in north Yemen in November 2009 . The Saudi government denied military use of phosphorus munitions against the rebels , saying they were flares , not phosphorus . Israeli - Palestinian conflict ( 2009 – 2012 ) . In September 2010 , reports of white phosphorus mortars hitting Eshkol regional council ( Israel ) " Eshkol Regional Council head Haim Yalin told Haaretz on Wednesday that " at about 6 : 30 in the morning the mortars began landing . By noon nine mortar shell hits had been identified , including two phosphorous ( sic ) ones . " " Rocket attacks launched by militants out of Gaza into southern Israel have been reported to use white phosphorus as late as March 2011 . The " Jerusalem Post " reported that in January 2012 , two mortars were fired from Gaza into the area governed by the Eshkol Regional Council which were determined by the Israeli military to have contained white phosphorus ; the shells were reported to have landed in open fields , causing no injuries or damage . The newspaper stated that the Eshkol Regional Council filed a formal complaint with the United Nations , noting that the Geneva Conventions prohibit the use of phosphorus against civilians . The IDF has admitted to using smoke shells containing white phosphorus on several occasions during the bombardment of the Gaza Strip following the expiration of the six - month truce between Israel and Hamas . Israel has also admitted that it used Incendiary Weapons against open unpopulated areas for marking and signaling purposes . Among the places worst affected by the use of white phosphorus was the UNRWA compound in Gaza City , at which Israeli forces fired three white phosphorus smoke shells on 15 January . The white phosphorus landed next to some fuel trucks and caused a large fire which destroyed tons of humanitarian aid . Prior to this strike , the compound had already been hit an hour earlier and the Israeli authorities had been informed by UNRWA officials and had given assurance that no further strikes would be launched on the compound . In another incident on the same day a white phosphorus smoke shell landed in the al - Quds hospital in Gaza City also causing a fire that forced hospital staff to evacuate the patients . The commander of the Gaza division , Brig . Gen . Eyal Eizenberg , and the commander of the Givati brigade , Col . Ilan Malka , were later disciplined for authorized the shelling . Use in Libya ( 2011 ) . During the NATO operation in Libya , some news sources reported about alleged use of white phosphorus by NATO forces . During the uprising , shells with white phosphorus and the use of cluster bombs over Misrata by Gaddafi forces had been also reported . Smoke - screening properties . Weight - for - weight , phosphorus is the most effective smoke - screening agent known , for two reasons : firstly , it absorbs most of the screening mass from the surrounding atmosphere and secondly , the smoke particles are an aerosol , a mist of liquid droplets which are close to the ideal range of sizes for Mie scattering of visible light . This effect has been likened to three dimensional textured privacy glass — the smoke cloud does not simply obstruct an image , but thoroughly scrambles both visual and infrared radiation , interfering with infrared optics and weapon - tracking systems , serving as a protection for military forces from guided weapons such as anti - tank missiles . When phosphorus burns in air , it first forms diphosphorus pentoxide ( which exists as tetraphosphorus decoxide except at very high temperatures ) : Diphosphorus pentoxide is extremely hygroscopic and quickly absorbs even minute traces of moisture to form liquid droplets of phosphoric acid : Since an atom of phosphorus has an atomic mass of 31 but a molecule of phosphoric acid has a molecular mass of 98 , the cloud is already 68 % by mass derived from the atmosphere ( i . e . 3 . 2 kilograms of smoke for every kilogram of WP ) ; it may absorb more because phosphoric acid and its variants are hygroscopic . Given time , the droplets will continue to absorb more water , growing larger and more dilute until they reach equilibrium with the local water vapour pressure . In practice , the droplets quickly reach a range of sizes suitable for scattering visible light and then start to dissipate from wind or convection . Because of the great weight efficiency of white phosphorus smoke , it is particularly suited for applications where weight is highly restricted , such as hand grenades and mortar bombs . An additional advantage for hand smoke grenades — which are more likely to be used in an emergency — is that the WP smoke clouds form in a fraction of a second . Because WP is also pyrophoric , most munitions of this type have a simple burster charge to split open the casing and spray fragments of WP through the air , where they ignite spontaneously and leave a trail of rapidly thickening smoke behind each particle . The appearance of this cloud forming is easily recognised ; one sees a shower of burning particles spraying outward , followed closely by distinctive streamers of white smoke , which rapidly coalesce into a fluffy , very pure white cloud ( unless illuminated by a coloured light source ) . Various disadvantages of white phosphorus are discussed below , but one which is particular to smoke - screening is " pillaring " . Because the WP smoke is formed from fairly hot combustion , the gasses in the cloud are hot , and tend to rise . Consequently the smoke screen tends to rise off the ground relatively quickly and form aerial " pillars " of smoke which are of little use for screening . Tactically this may be counteracted by using white phosphorus to get a screen quickly , but then following up with emission type screening agents for a more persistent screen . Some countries have begun using red phosphorus instead . Red phosphorus ( " RP " ) burns cooler than WP and eliminates a few other disadvantages as well , but offers exactly the same weight efficiency . Other approaches include white phosphorus - soaked felt pads ( which also burn more slowly , and pose a reduced risk of incendiarism ) and PWP , or plasticised white phosphorus . Effects on people . White phosphorus can cause injuries and death in three ways : by burning deep into tissue , by being inhaled as a smoke , and by being ingested . Extensive exposure by burning and ingestion is fatal . Burning . Incandescent particles of WP cast off by a WP weapon ' s initial explosion can produce extensive , deep second and third degree burn s . One reason why this occurs is the tendency of the element to stick to the skin . Phosphorus burns carry a greater risk of mortality than other forms of burns due to the absorption of phosphorus into the body through the burned area , resulting in liver , heart and kidney damage , and in some cases multiple organ failure . These weapons are particularly dangerous to exposed people because white phosphorus continues to burn unless deprived of oxygen or until it is completely consumed . In some cases , burns are limited to areas of exposed skin because the smaller WP particles do not burn completely through personal clothing before being consumed . Smoke inhalation . Burning white phosphorus produces a hot , dense , white smoke consisting mostly of phosphorus pentoxide . Exposure to heavy smoke concentrations of any kind for an extended period ( particularly if near the source of emission ) has the potential to cause illness or death . White phosphorus smoke irritates the eyes , mucous membranes of the nose , and respiratory tract in moderate concentrations , while higher concentrations can produce severe burns . The Agency for Toxic Substances and Disease Registry has set an acute inhalation Minimum Risk Level ( MRL ) for white phosphorus smoke of 0 . 02 mg / m³ , the same as fuel - oil fumes . By contrast , the chemical weapon mustard gas is 30 times more potent : 0 . 0007 mg / m³ . Oral ingestion . The accepted lethal dose when white phosphorus is ingested orally is 1 mg per kg of body weight , although the ingestion of as little as 15 mg has resulted in death . It may also cause liver , heart or kidney damage . There are reports of individuals with a history of oral ingestion who have passed phosphorus - laden stool ( " smoking stool syndrome " ) . Its extreme toxicity is due to the generation of free radicals , especially in the liver , where they accumulate and are not easily metabolized . Arms control status and military regulations . There are multiple international laws that could be seen to regulate white phosphorus use . Article 1 of Protocol III of the Convention on Certain Conventional Weapons defines an incendiary weapon as ' any weapon or munition which is primarily designed to set fire to objects or to cause burn injury to persons through the action of flame , heat , or combination thereof , produced by a chemical reaction of a substance delivered on the target ' . The same protocol prohibits the use of said incendiary weapons against civilians ( already forbidden by the Geneva Conventions ) or in civilian areas . The convention also defines weapons which are not to be considered to be incendiary weapons . Examples are : ( i ) Munitions which may have incidental incendiary effects , such as illuminants , tracers , smoke or signalling systems ; ( ii ) Munitions designed to combine penetration , blast or fragmentation effects with an additional incendiary effect . Weapons containing White Phosphorus , but are not Incendiary Weapons , are not regulated by the above protocol . However , the use against military targets outside civilian areas is not explicitly banned by any treaty . The convention is meant to prohibit weapons that are " dependent on the use of the toxic properties of chemicals as a method of warfare " ( Article II , Definitions , 9 , " Purposes not Prohibited " c . ) . The convention defines a " toxic chemical " as a chemical " which through its chemical action on life processes can cause death , temporary incapacitation or permanent harm to humans or animals " ( CWC , II ) . An annex lists chemicals that fall under this definition and WP is not listed in the Schedules of chemical weapons or precursors . In an 2005 interview with RAI , Peter Kaiser , spokesman for the Organisation for the Prohibition of Chemical Weapons ( an organization overseeing the CWC and reporting directly to the UN General Assembly ) , questioned whether the weapon should fall under the convention ' s provisions : Kaiser was a staff spokesman for the Organisation for the Prohibition of Chemical Weapons . The OPCW , using member votes , creates Schedules of chemical weapons or dual - use chemicals of concern and white phosphorus is not in any of these schedules . The Convention on Certain Conventional Weapons , not the Chemical Weapons Convention , goes on , in its Protocol III , to prohibit the use of all air - delivered incendiary weapons against civilian populations , or for indiscriminate incendiary attacks against military forces co - located with civilians . However , that protocol also specifically excludes weapons whose incendiary effects are secondary , such as smoke grenades . This has often been read as excluding white phosphorus munitions from this protocol , as well . Several countries , most notably Israel , are not signatories to Protocol III . The legal position however , is not the only consideration in any war . For instance , concerning the U . S . use of white phosphorus in Iraq , the British Liberal Democrat foreign affairs spokesman Sir Menzies Campbell , said Military regulations . Within the US Army , there appears to be conflicting advice on the use of WP against humans . According to the field manual on the Rule of Land Warfare , " The use of weapons which employ fire , such as tracer ammunition , flamethrowers , napalm and other incendiary agents , against targets requiring their use is not violative of international law . " However , the 1999 " ST 100 - 3 Battle Book " , a student text published by the US Command and General Staff College at Fort Leavenworth , states that " It is against the law of land warfare to employ WP against personnel targets . " At the same time , other field manuals discuss the use of white phosphorus against personnel . Though white phosphorus is still used in modern armed conflict , its use in incendiary weapons is regulated by international humanitarian law , or the law of war .