Iran Chemical Overview

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Iran is one of the few countries in the world that has encountered chemical warfare (CW) on the battlefield since 1918.

Iranian troops and civilians suffered tens of thousands of casualties from Iraqi chemical weapons during the Iran-Iraq War of 1980 to 1988. As a result, Iran has strongly opposed the use and possession of chemical weapons. Iran ratified the Chemical Weapons Convention (CWC) in 1997. Nevertheless, several Western governments have accused Iran of developing and maintaining its own arsenal of chemical weapons since it ratified the CWC. Although between 1997 and 2003, U.S. intelligence agencies accused Iran of maintaining a stockpile of chemical weapons, these assessments largely changed after 2003. No effort has been made to take advantage of the challenge inspection mechanisms provided by the CWC to investigate purported Iranian chemical facilities. Moreover, none of the allegations made regarding the stockpiling of CW agents can be verified using information available in the unclassified domain.

Assessing Iran’s CW capabilities is difficult—although there is an apparent wealth of information, very little of it constitutes original material. The greater part of published information on Iran’s CW programs consists of repackaged information from a limited number of sources. The tendency to fit new information into a pre-existing framework that presumes the existence of a covert offensive CW program introduces additional problems. Ultimately, all public assessments of Iran’s alleged CW program depend heavily upon information gathered from Iranian opposition groups and Western intelligence agencies. Doubts about the validity of information publicly released by Western intelligence agencies have increased since 2003 due to investigations that revealed selective reporting, the use of unreliable or biased sources, an unwillingness to emphasize uncertainty, and a failure to properly assess the veracity or reliability of available information. ¹ Nonetheless, revelations since 2003 regarding the extent of Iran’s previously concealed civilian nuclear program do raise the question of whether Iran might indeed be hiding a CW program. To piece together an objective overview of allegations surrounding Iran and its CW capabilities, the following profile mines open source literature while taking into consideration the above-mentioned problems and limitations.

Iran has a sophisticated base for the development of a chemical warfare (CW) program that dates back to the Iran-Iraq War (1980 to 1988) – a conflict that gave Iran strong incentives for developing a robust chemical defense capability. Several unclassified allegations and reports from the 1990s until approximately 2003 suggested that Iran had developed an offensive CW program. Many of these claims described specific military capabilities related to agent stockpiles, delivery systems, and deployments that cannot be independently verified in open sources. ²

Instead, open source reports of Iranian transactions involving various dual-use materials have been interpreted as supporting claims for the existence of an offensive CW program. Iran has imported chemicals such as thiodiglycol and thionyl chloride that can be applied towards legitimate purposes such as dyes, textiles, and pesticides or could be diverted towards an illicit CW program. ³ In the mid-1990s, Iran also imported several tons of phosphorus pentasulfide, which is on the Australia Group’s watch list for controlled chemical precursors, but not on the Chemical Weapons Convention (CWC) Schedule lists. ⁴ Although this compound has several legitimate uses—including pesticide production (most notably malathion) and as an additive for lubricant oil—it is also a starting point for the production of V-group nerve agents. ^{5 6} Notably, U.S. intelligence estimates and State Department compliance reports between 2003 and 2010 do not list any specific CW agents possessed by Iran, and have removed all previous references to agent stockpiles or delivery systems. ⁷ These recent reports suggest that the U.S. intelligence community is either uncertain about or unwilling to publicly disclose the specifics of any Iranian offensive CW program.

1980 to 1988: Chemical Weapons and the Iran-Iraq War

The Iran-Iraq War of 1980 to 1988 prompted Iran’s involvement with chemical weapons. Beginning in 1983, Iran suffered the effects of increasingly effective Iraqi CW attacks, which initially involved blister agents (e.g. mustard gas), but later included nerve agents such as tabun and possibly sarin. ⁸ Estimates of the number of Iranian casualties from Iraqi CW use are not definitive, but the Iranian estimate is 60,000 casualties. ⁹

The weak international response, particularly by the United Nations, to Iraqi use of chemical weapons against Iranian forces left Iran increasingly bitter about what it perceived to be a double standard in the enforcement of international agreements. Many Iranian officials concluded that their country had to develop the ability to retaliate in kind to deter chemical weapons use. In a 1987 interview, the Iranian representative to the United Nations (UN) stated that “…if the Iraqi regime does not take any steps in putting an end to the crimes of the Iraqi regime, we will retaliate in kind, and in that case, we will certainly announce it.” ¹⁰

Others within the clerical Islamic regime publicly condemned any use of chemical weapons on moral grounds, calling them un-Islamic. ¹¹ However, there has been official confirmation that Iran at one point pursued offensive CW capabilities. In November 1998, Iranian Ambassador Mohammad R. Alborzi, Director General of the Iranian Foreign Ministry, delivered a statement to the Conference of the States Parties (CSP) to the CWC in The Hague, The Netherlands. In his statement, he admitted for the first time that Iran had once possessed CW, in the waning years of the Iran-Iraq War. But he claimed that, “…following the establishment of [the] ceasefire, the decision to develop chemical weapons capabilities was reversed and the process was terminated.” ¹²

Some reports suggest that Iran may have employed those CW agents on a small scale during the 1980s war with Iraq; however, an intensive review of the open literature (including UN reports based on field investigations from that era) provides insufficient evidence to support this conclusion. ¹³ During the 2003 invasion of Iraq, U.S. forces discovered internal Iraqi intelligence reports that discussed Iranian use of CW agents against the Iraqis along with the capture of 141 CW mortar rounds, which were presented to the United Nations. According to the UN inspectors, the rounds’ storage containers tested positive for mustard gas, but tests on the contents of the munitions were inconclusive. ¹⁴ There are also unconfirmed allegations that Iran sent chemical munitions to Libya in exchange for Scud B ballistic missiles. Iraqi intelligence reports from the war cite Egyptian sources that claimed to have uncovered the deal. ¹⁵ CW munitions uncovered by Libyan rebels during the 2011 Libyan Civil War have reportedly been traced back to Iran. ¹⁶

1988 to 2003: Potential Chemical Warfare Capabilities

Although Iran admitted to previously pursuing an offensive CW capability—its initial report to the OPCW declared a single CW production facility—it has not provided any public accounting of the details of that program. Beyond the confirmation by OPCW inspectors that the facility was closed and demolished prior to entry into force of the CWC, little public information exists regarding Iran’s possible continued pursuit of CW capabilities. What evidence does exist must come from analysis of instances in which Iran imported bulk quantities of precursors for chemical warfare agents. According to Jane’s, the Federal Republic of Germany (West Germany) allegedly exported dual-use chemical materials and technology to Iran during the 1980s. ¹⁷ The mustard gas precursor thiodiglycol was of particular interest to the Iranians. In 1989, U.S. authorities clamped down on the chemical company Alcolac International Inc., of Baltimore, Maryland, which illegally shipped almost 120 tons of thiodiglycol to Iran. ¹⁸

India is also heavily implicated in exports of CW materials to Iran. The State Trading Corporation of India conceded in 1989 that it had sold over 60 tons of the nerve agent precursor thionyl chloride to Iran, and a shipment of an additional 257 tons was planned. ¹⁹ A decade later, the press reported chemical warfare implications in a 1997 multi-million dollar deal that India cut with Iran to construct an advanced chemical plant near Tehran, at Qazvim. ²⁰ India was also purportedly involved in a botched sale to Iran of phosphorous pentasulfide, a chemical that could be utilized in pesticides or in the nerve agent VX. In 1998, reports indicated that China successfully concluded a similar arrangement with Iran for the sale of 500 tons of phosphorus pentasulfide. ²¹

Other states have become involved in CW-related sales as well. In 1997, Nahum Manbar – an Israeli – was convicted of attempting to sell the technology and equipment necessary to produce mustard gas, as well as the knowledge necessary to produce tabun (a nerve gas), to Iran during the early 1990s. ²² Though it is unclear whether his attempted sale was successful, Manbar was sentenced to 15 years in prison. Several years after his sentencing, a former MI6 agent, Richard Tomlinson, published a book in which he claimed that Manbar was actually working on behalf of Mossad, Israel’s intelligence service. However, MI6, the CIA, and Mossad all deny his claims. ²³

In the past, Jane’s and other sources alleged that Chinese companies were involved in sales of CW technology to Iran; as a result, several Chinese companies and individuals have faced U.S. sanctions. In 1995, the U.S. State Department announced sanctions against Asian-Ways, Ltd., World Co (Hong Kong) Ltd., and Mainway International Ltd. for supplying Iran with “nerve gas technology.” ²⁴ According to U.S. press accounts citing a top secret CIA report dated October 2, 1996, China sold Iran nearly 400 metric tons of carbon disulfide, a precursor to riot control and nerve agents. ²⁵ Despite these sales, there is no clear evidence that Iran has produced tear gas or other riot control agents. In 1997, the U.S. State Department sanctioned two additional Chinese companies for selling Iran CW-related precursors and equipment. ²⁶ The U.S. State Department has also sanctioned several individuals, including Chinese national Qingchang (Q.C.) Chen, for allegedly supplying Iran with material linked to CW. ²⁷

In 2000, the U.S. government passed the Iran Nonproliferation Act, followed in 2005 by extended guidelines that led to the renaming of the measure to the Iran and Syria Nonproliferation Act. Pursuant to this act, the United States has sanctioned numerous entities and individuals in several countries, particularly India and China, for the export of dual-use materials to Iran.

In 2000, the CIA estimated that Iran “[possessed] a stockpile of at least several thousand metric tons of weaponized and bulk agent.” ²⁸ In 2002, a CIA unclassified report claimed that Iran’s stockpile of CW agents reportedly included blister, blood, and choking agents, and possibly nerve agents. ²⁹ According to several observers, Iran allegedly developed this capability with aid from Western individuals and companies, as well as from other nations, such as India and China. ³⁰

2003 to the Present: Varying Assessments

While Iran’s history of possible CW-related imports suggests a possible offensive chemical weapons program, since 2003 U.S. intelligence assessments have refrained from definitive conclusions. Prior to that date, intelligence estimates included specific assessments of Iran’s CW program, including the agents Iran allegedly stockpiled. The last of these more detailed reports, issued in 2003, stated that Iran “may have already stockpiled blister, blood, choking, and possibly nerve agents-and the bombs and artillery shells to deliver them-which it previously had manufactured.” ³¹

In 2004, however, the Director of National Intelligence stated that “Iran is a party to the CWC. Nevertheless, during the reporting period it continued to seek production technology, training, and expertise from foreign entities that could further Tehran’s efforts to achieve an indigenous capability to produce nerve agents.” ³² In 2007, the U.S. intelligence community stated that: “Iran maintains the capability to produce CW agent in times of need and conducts research that may have offensive applications.” ³³ Gone was the specificity that had been the hallmark of past U.S. intelligence assessments, suggesting at a minimum that the threat level was being reconsidered. ³⁴ Subsequent reports have followed this general pattern. A 2011 CIA report of a similar nature assessed that “Tehran continues to seek dual-use technologies that could advance its capability to produce CW agents.” ³⁵ It furthermore judged that “Iran is capable of weaponizing CW agents in a variety of delivery systems,” but gave not indication that Iran had done so. ³⁶

Iran has also apparently sought materials for a chemical weapons defense capability, which the CWC allows. In 1997 China sold Iran 40,000 barrels of calcium-hypochlorite, a chemical and biological decontaminating agent. ³⁷ Iran also reportedly purchased respirators from Spain, protective gear from South Korea, and atropine auto-injectors from the Netherlands. ³⁸

Whether or not Iran has a stockpile of poison gas, Iran has extensive weaponry that could be adapted to deliver CW agents. In 1996, Jane’s cited various reports that Iran had “developed 155mm artillery shells, mortar rounds, aerial bombs for chemical fill, and possibly chemical warheads for Scuds.” ³⁹ Jane’s and other news outlets circulated reports that Iran utilized mines as delivery systems for chemical agents. ⁴⁰ Iran’s Shahab missile is also believed to be capable of carrying chemical warheads. ⁴¹ Similarly, Iran has been developing unmanned aerial vehicles, which some experts claim could be used for delivery of chemical or biological agents. ⁴²

Iran also reportedly possesses a number of cruise missiles such as the Kh-55 Granat, which are well-suited to deliver chemical or biological warheads. Received from Ukraine in approximately 2001, these cruise missiles could conceivably be configured for the delivery of CW agents, but experts debate whether Iran has the means to launch the actual missiles. ⁴³ The September 2007 claims from Jane’s and other international news sources that a CW-related explosion occurred at a Syrian military facility when Iranian and Syrian engineers attempted to fit a chemical warhead onto a Scud missile have been disputed. ⁴⁴ There are some accusations that cooperation between Iran and the Syrian government on chemical weapons continued through the Syrian Civil War. In January 2012, the Turkish government claimed to have halted a convoy of Iranian trucks en route to Syria because of suspicions that they carried military equipment. ⁴⁵ Soon after the incident, former British Prime Minister David Cameron charged Iran with providing the Syrian regime with weapons and stated “there have been interceptions of some shipments by Turkey which are particularly interesting.” ⁴⁶ Several Israeli sources went further, contending that the convoy was carrying CW material in addition to conventional weapons. They based their accusations on a report by the Turkish newspaper Taraf, which was shut down by the Turkish government after the attempted coup in 2016. ⁴⁷ Iran has strongly rejected the claims that it is sending any weapons to Syria. ⁴⁸

Officially, Iran has consistently denied possession of chemical weapons. After the adoption of UN Security Council Resolution 1540 in April 2004, Iran continued to maintain that it did not possess such weapons. In a note to the UN Security Council in 2006 regarding its implementation of Resolution 1540, Iran’s representatives stated that “the Islamic Republic of Iran, as a State party to all international legal instruments banning WMD, does not possess WMD and considers these kinds of weapons as inhumane, immoral, illegal, and against its very basic principles.” ⁴⁹ Within the framework of the CWC and under the auspices of the Organization for the Prohibition of Chemical Weapons, Iran has hosted training sessions on the medical aspects of chemical warfare. ⁵⁰ In the international arena, Iran consistently points to its adherence to the CWC and denies any secret CW program.

Iran has continued to import potential CW agent precursors; however, since these chemicals have legitimate civilian applications, such imports are not conclusive evidence that Iran is developing or maintaining a CW program. Between 1997 and 2013, the United States sanctioned a variety of international companies in relation to Iran’s WMD programs, including the Chinese firms Zibo Chemet Equipment Company, Liyand Chemical Equipment Company, and the Nanjing Chemical Industries Group. ⁵¹ According to the U.S. State Department, these companies have either “engaged in chemical weapons proliferation” ⁵² or in “activities…having the potential to make a material contribution to weapons of mass destruction (WMD) or cruise or ballistic missile systems.” ⁵³ Though the specific reason for the sanctions against Zibo Chemet, for example, is unclear, the company is “a major manufacturer of gas-lined chemical equipment.” ⁵⁴ Glass-lined, corrosion-resistant equipment was often employed in the production of CW agents, and at one time its use in the chemical industry was uncommon. Now, it is an increasingly important component in facilities for the production of pesticides and fertilizers using modern processes. Similar statements can be made concerning the other Chinese firms;—the equipment that they manufacture has dual-use civilian applications as well.

Despite a lack of evidence suggesting CW-related activities, many Western states view ongoing efforts to increase the size and sophistication of the Iranian chemical industry with suspicion. Past accusations, however, should be balanced against the dearth of reliable open source information, more recent and less definitive intelligence assessments, and the fact that CWC inspections of Iranian facilities have not revealed any evidence of an illicit CW program. Furthermore, the Congressional Research Service deems it unlikely that Iran would transfer any chemical or biological weapons to non-state actors for fear of international backlash. ⁵⁵