Chemical weapon A chemical weapon ( CW ) is a device that uses chemicals formulated to inflict death or harm on human beings . They may be classified as weapons of mass destruction though they are separate from biological weapons ( diseases ) , nuclear weapon s and radiological weapon s ( which use radioactive decay of elements ) . Chemical weapons can be widely dispersed in gas , liquid and solid forms and may easily afflict others than the intended targets . Nerve gas and tear gas are two modern examples . Lethal , unitary , chemical agents and munitions are extremely volatile and they constitute a class of hazardous chemical weapons that are now being stockpile d by many nations . ( Unitary agents are effective on their own and require no mixing with other agents . ) The most dangerous of these are nerve agent s GA , GB , and VX , and vesicant ( blister ) agents which are formulations of sulfur mustard such as H , HT , and HD . All are liquids at normal room temperature , but become gaseous when released . Widely used during the First World War , the effects of so - called mustard gas , phosgene gas and others caused lung searing , blindness , death and maiming . Under the Chemical Weapons Convention ( 1993 ) , there is a legally - binding , world - wide ban on the production , stockpiling , and use of chemical weapons and their precursor s . Notwithstanding , large stockpiles thereof continue to exist , usually justified as only a precaution against putative use by an aggressor . International law on chemical weapons . Before the Second World War . International law has prohibited the use of chemical weapons since 1899 , under the Hague Convention : Article 23 of the Regulations Respecting the Laws and Customs of War on Land adopted by the First Hague Conference " especially " prohibited employing " poison and poisoned arms " ; also , a separate Declaration stated that in any war between signatory powers , the parties would abstain from using projectiles " the object of which is the diffusion of asphyxiating or deleterious gases . " The Washington Naval Treaty , signed February 6 , 1922 , also known as the Five - Power Treaty , aimed at banning CW — but did not succeed because the French rejected it . The subsequent failure to include CW has contributed to the resultant increase in stockpiles . The Geneva Protocol , officially known as the " Protocol for the Prohibition of the Use in War of Asphyxiating , Poisonous or other Gases , and of Bacteriological Methods of Warfare " , is an International treaty prohibiting the use of chemical and biological weapons . It was signed at Geneva June 17 , 1925 and entered into force on February 8 , 1928 . 133 nations are listed as state parties to the treaty — Ukraine acceded August 7 , 2003 and is the most recent member nation . This treaty states that chemical and biological weapons are " justly condemned by the general opinion of the civilised world . " While the treaty prohibits the use of chemical and biological weapons , it does not address the production , storage , or transfer of these weapons . Later treaties did address those omissions and have been enacted . Modern agreements . The Chemical Weapons Convention ( CWC ) is the most recent arms control agreement with the force of International law . Its full name is the " Convention on the Prohibition of the Development , Production , Stockpiling and Use of Chemical Weapons and on their Destruction " . That agreement outlaws the production , stockpiling and use of chemical weapons . It is administered by the Organisation for the Prohibition of Chemical Weapons ( OPCW ) , which is an independent organization based in The Hague . The OPCW administers the terms of the CWC to 188 signatories which represents 98 % of the global population . Of the stockpiles , 44 , 131 of the 71 , 194 tonnes declared ( 61 . 99 % ) have been destroyed . The OPCW has conducted 4 , 167 inspections at 195 chemical weapon - related and 1 , 103 industrial sites . These inspections have affected the sovereign territory of 81 States Parties since April 1997 . Worldwide , 4 , 913 industrial facilities are subject to inspection provisions . Use . Chemical warfare ( " CW " ) involves using the toxic properties of chemical substance s as weapons . This type of warfare is distinct from Nuclear warfare and Biological warfare , which together make up NBC , the military initialism for Nuclear , Biological , and Chemical ( warfare or weapons ) . None of these falls under the term conventional weapons which are primarily effective owing to their destructive potential . Chemical warfare does not depend upon explosive force to achieve an objective . Rather it depends upon the unique properties of the chemical agent weaponized . A lethal agent is designed to injure or incapacitate the enemy , or deny unhindered use of a particular area of terrain . Defoliant s are used to quickly kill vegetation and deny its use for cover and concealment . An agent can also be used against agriculture and livestock to promote hunger and starvation . Chemical payloads can be delivered by remote controlled container release , aircraft , or rocket . Protection against chemical weapons includes proper equipment , training , and decontamination measures . Countries with stockpiles . CWC states with declared stockpiles . Of 190 signatory nations to the CWC , state parties listed below have also declared stockpiles , agreed to monitored disposal , and verification , and in some cases , used CW in conflict . Both military targets and civilian populations have been affected — the affected populations were not always damaged collaterally , but rather at times , the target of the attack . As of 2012 , only four nations are confirmed as having chemical weapons : the United States , Russia , North Korea and Syria . India . India declared its stock of chemical weapons in June 1997 . India ' s declaration came after the entry into force of the CWC that created the OPCW . India declared a stockpile of 1044 tonnes of sulphur mustard in its possession . On January 14 , 1993 India became an original signatory to the CWC . By 2005 , from among the six nations that had declared possession of chemical weapons , India was the only one to meet its deadline for chemical weapons destruction and for inspection of its facilities by the OPCW . By the end of 2006 , India had destroyed more than 75 percent of its chemical weapons / material stockpile and was granted extension for destroying ( the remaining stocks by April 2009 ) and was expected to achieve 100 percent destruction within that time frame . On May 14 , 2009 , India informed the United Nations that it has destroyed its stockpile of chemical weapons . Iraq . The Organisation for the Prohibition of Chemical Weapons which oversees destruction measures has announced " The government of Iraq has deposited its instrument of accession to the Chemical Weapons Convention with the Secretary General of the United Nations and within 30 days , on 12 February 2009 , will become the 186th State Party to the Convention " . Iraq has also declared stockpiles of CW , and because of their recent accession is the only State Party exempted from the destruction time - line . On September 7 , 2011 Mr . Hoshyar Zebari entered the OPCW headquarters , becoming the first Iraqi Foreign Minister to officially visit since the country joined the CWC . On June 28 , 1987 , Iraqi aircraft delivered what was believed to be mustard gas in an attack against the Iranian city of Sardasht . On two separate attacks against four residential areas , victims were estimated as 10 civilians dead and 650 civilians injured . Japan . Japan stored chemical weapons on the territory of mainland China between 1937 and 1945 . The weapons mostly contained a mustard gas - lewisite mixture . The weapons are classified as abandoned chemical weapons under the CWC and Japan has started their destruction in September 2010 in Nanjing using mobile destruction facilities . Libya . Libya used chemical weapons under Muammar Gaddafi ' s regime in a war with Chad . In 2003 Gaddafi agreed to accede to the convention in exchange for " rapprochement " with western nations . At the time of the Libyan uprising against Gaddafi , Libya still controlled approximately 11 . 25 tons of poisonous mustard gas . Because of destabilization , concerns have increased regarding possibilities and likelihood that control of these agents could be lost . With terrorism as a core concern , international bodies are seeking to ensure Libya is held to its obligations under the treaty . Libya ' s post - Gaddafi National Transitional Council is cooperating with the Organization for the Prohibition of Chemical Weapons regarding the destruction of all legacy chemical weapons in the country . After assessing the chemical stockpiles the Libyan government will receive a deadline from the OPCW to destroy the weapons . Russia . Russia entered the CWC with the largest declared stockpile of chemical weapons . By 2010 the country had destroyed 18 , 241 tonnes at destruction facilities located in Gorny ( Saratov Oblast ) and Kambarka ( Udmurt Republic ) — where operations have finished — and Shchuchye ( Kurgan Oblast ) , Maradykovsky ( Kirov Oblast ) , Leonidovka ( Penza Oblast ) while installations are under construction in Pochep ( Bryansk Oblast ) and Kizner ( Udmurt Republic ) . United States . The U . S . stored its chemical weapons at eight U . S . Army installations within the Continental United States ( CONUS ) . The stockpiles were maintained in exclusion zones at the following Department of Army installations ( the percentages shown are reflections of amount by weight ) : Tooele Army Depot ( TEAD ) , Utah ( 42 . 3 % of total stockpile ) ; Pine Bluff Arsenal ( PBA ) , Arkansas ( 12 % ) ; Umatilla Depot Activity ( UMDA ) , Oregon ( 11 . 6 % ) ; Pueblo Depot Activity ( PUDA ) , Colorado ( 9 . 9 % ) ; Anniston Army Depot ( ANAD ) , Alabama ( 7 . 1 % ) ; Aberdeen Proving Ground ( APG ) , Maryland ( 5 % ) ; Newport Army Ammunition Plant ( NAAP ) , Indiana ( 3 . 9 % ) ; and Blue Grass Army Depot ( BGAD ) , Kentucky ( 1 . 6 % ) . The remaining 6 . 6 % was located on Johnston Atoll in the Pacific Ocean . Currently stockpiles have been eliminated at Johnston Atoll , APG , NAAP , UMDA , PBA TEAD . , and ANAD . PUDA will begin elimination during FY 2015 , and complete in FY 2017 . BGAD will be last to complete this elimination which tentative dates have not been set . The U . S . policy on the use of chemical weapons is to reserve the right to retaliate . First use , or preemptive use , is a violation of stated policy . Only the president of the United States can authorize the first retaliatory use . Official policy now reflects the likelihood of chemical weapons being used as a terrorist weapon . Syria . Prior to September 2013 , Syria was one of only 7 states which are not party to the Chemical Weapons Convention . However , it is party to the 1925 Geneva Protocol prohibiting the use of chemical weapons in war but has nothing to say about production , storage or transfer . Syrian officials have stated that they feel it appropriate to have some deterrent against Israel ' s similarly non - admitted nuclear weapons program when questioned about the topic , but only on July 23 , 2012 , the Syrian government acknowledged for the first time that it had chemical weapons Independent assessments indicate that Syrian production could be up to a combined total of a few hundred tons of chemical agent per year . Syria reportedly manufactures Sarin , Tabun , VX , and mustard gas types of chemical weapons . Syrian chemical weapons production facilities have been identified by Western nonproliferation experts at approximately 5 sites , plus one suspected weapons base : In July 2007 , a Syrian arms depot exploded , killing at least 15 Syrians . Jane ' s Defence Weekly , a U . K . magazine reporting on military and corporate affairs , believed that the explosion happened when Iranian and Syrian military personnel attempted to fit a Scud missile with a mustard gas warhead . Syria stated that the blast was accidental and not chemical related . On July 13 , 2012 , the Syrian government moved its stockpile to an undisclosed location . In September 2012 , information emerged that the Syrian military had begun chemical weapons tests and was reinforcing and resupplying a base housing these weapons located east of Aleppo in August . On March 19 , 2013 , news emerged from Syria indicating the first use of chemical weapons since the beginning of the Syrian uprising . On August 21 , 2013 , testimony and photographic evidence emerged from Syria indicating a large - scale chemical weapons attack on Ghouta , a populated urban center . On October 14 , 2013 , Syria officially acceded to the Chemical Weapons Convention . Non - CWC states with stockpiles . Israel . Although Israel has signed the CWC , it has not ratified the treaty and therefore is not officially bound by its tenets . The country is believed to have a significant stockpile of chemical weapons , likely the most abundant in the Middle - East , according to the Russian Foreign Intelligence Service . In a 1983 CIA Report , it was stated that Israel , after " finding itself surrounded by front - line Arab states with budding CW capabilities , became increasingly conscious of its vulnerability to chemical attack . . . undertook a program of chemical warfare preparations in both offensive and protective areas . . . In late 1982 a probable CW nerve agent production facility and a storage facility were identified at the Dimona Sensitive Storage Area in the Negev Desert . Other CW agent production is believe to exit within a well - developed Israeli chemical industry . " In 1992 , El Al Flight 1862 crashed on its way to Tel Aviv and was found to be carrying CWC schedule 2 chemical , which is a precursor to the production of sarin nerve gas , a prohibited chemical weapon of mass destruction prohibited by the CWC . Israel insisted at the time that the materials were non - toxic . This shipment was coming from a US chemical plant to the IIBR under a US Department of Commerce license . In 1993 , the U . S . Congress Office of Technology Assessment WMD proliferation assessment recorded Israel as a country generally reported as having undeclared offensive chemical warfare capabilities . North Korea . North Korea is not a signatory of CWC and has never officially acknowledged the existence of its offensive CW program . Nevertheless , the country is believed to possess a substantial arsenal of chemical weapons . It reportedly acquired the technology necessary to produce tabun and mustard gas as early as the 1950s . In 2009 the International Crisis Group reported that the consensus expert view was that North Korea had a stockpile of about 2 , 500 to 5 , 000 tonnes of chemical weapons , including mustard gas , sarin ( GB ) and other nerve agent s . Framework For Elimination of Syrian Chemical Weapons . An agreement was reached September 14 , 2013 called the Framework For Elimination of Syrian Chemical Weapons ; leading to the elimination of Syria ' s chemical weapon stockpiles by mid - 2014 . Manner and form . There are three basic configurations in which these agents are stored . The first are self - contained munitions like projectiles , cartridges , mines , and rockets ; these can contain propellant and / or explosive components . The next form are aircraft - delivered munitions . This form never has an explosive component . Together they comprise the two forms which have been weaponized and are ready for their intended use . The U . S . stockpile consisted of 39 % of these weapon ready munitions . The final of the three forms are raw agent housed in one - ton containers . The remaining 61 % of the stockpile was in this form . Whereas these chemicals exist in liquid form at normal room temperature , the sulfur mustards H , and HD freeze in temperatures below . Mixing lewisite with distilled mustard lowers the freezing point to . Higher temperatures are a bigger concern because the possibility of an explosion increases as the temperatures rise . A fire at one of these facilities would endanger the surrounding community as well as the personnel at the installations . Perhaps more so for the community having much less access to protective equipment and specialized training . The Oak Ridge National Laboratory conducted a study to assess capabilities and costs for protecting civilian populations during related emergencies , and the effectiveness of expedient , in - place shelters . Disposal . The stockpiles , which have been maintained for more than 50 years , are now considered obsolete . Public Law 99 - 145 , contains section 1412 which directs the Department of Defense ( DOD ) to dispose of the stockpiles . This directive fell upon the DOD with joint cooperation from the Federal Emergency Management Agency ( FEMA ) . The Congressional directive has resulted in the present Chemical Stockpile Disposal Program . Some places where chemical weapons were tested , such as the San Jose Project in Panama , were not included in the disposal program . Thousands of mines on the island are still full of chemical gas and can be set off by passersby . Historically , chemical munitions have been disposed of by land burial , open burning , and ocean dumping ( referred to as Operation CHASE ) . However in 1969 , the National Research Council ( NRC ) recommended that ocean dumping be discontinued . The Army then began a study of disposal technologies , including the assessment of incineration as well as chemical neutralization methods . In 1982 , that study culminated in the selection of incineration technology , which is now incorporated into what is known as the " baseline " system . Construction of the Johnston Atoll Chemical Agent Disposal System ( JACADS ) began in 1985 . This was to be a full - scale prototype facility using the baseline system . The prototype was a success but there were still many concerns about CONUS operations . To address growing public concern over incineration , Congress , in 1992 , directed the Army to evaluate alternative disposal approaches that might be " significantly safer " , more cost effective , and which could be completed within the established time frame . The Army was directed to report to Congress on potential alternative technologies by the end of 1993 , and to include in that report — " any recommendations that the National Academy of Sciences makes . . . " . In June 2007 the disposal program achieved a milestone reaching 45 % destruction of the chemical weapon stockpile . The Chemical Materials Agency ( CMA ) releases regular updates to the public regarding the status of the disposal program . By October 2010 , the program had reached 80 % destruction status . Lethality . Chemical weapons are said to " make deliberate use of the toxic properties of chemical substances to inflict death " . At the start of World War II it was reported in newspapers that " entire regions of Europe " would be turned into " lifeless wastelands " . However , chemical weapons were not used to the extent feared . An unintended chemical weapon release occurred at the port of Bari . A German attack on the evening of December 2 , 1943 , damaged U . S . vessels in the harbour and the resultant release of mustard gas inflicted a total of 628 casualties . The U . S . Government was highly criticized for exposing American service members to chemical agents while testing the effects of exposure . These tests were often performed without the consent or prior knowledge of the soldiers affected . Many Australian service personnel were also exposed as a result of the " Brook Island trials " carried out by the British Government to determine the likely consequences of chemical attack in tropical conditions , about which little was then known . Some chemical agents are designed to produce mind altering changes rendering the victim unable to perform their assigned mission . These are classified as incapacitating agents and lethality is not a factor of their effectiveness . Unitary versus binary weapons . Unitary munitions are opposite of binary munitions . Binary munitions contain two , unmixed and isolated chemicals which do not react to produce lethal effects until mixed . This usually happens just prior to battlefield use . In contrast , unitary weapons are lethal chemical munitions which produce a toxic result in their existing state . The majority of the chemical weapon stockpile is unitary and most of it is stored in one - ton bulk containers .