The following information is from 1992-95 ASA Newsletter files and an ASA paper presented to the CBMTS-Industry I in 1998.

Yugoslav Chemical Warfare Capability. Mostar's History of Chemical Weapon Research, Development, Production: What, When, Where, How Much?

In October 1992, ASA was the very first to report on the Mostar CW Research, Development and Production facility. The former Yugoslavia had managed to develop its chemical weapons program in such a high degree of secrecy that not even the Stockholm International Peace Research Institute (SIPRI), which prided itself on having one of the best CW data bases in the world, had ever even mentioned in its annual reports that Yugoslavia was working on such a program. The very large “Mostar” CW plant, which covered some 52 hectares in the village of Potoci, 10 kms northeast of Mostar, was ideally suited to the secrecy of the program.

The Military Technical Institute, Belgrade, started its CW production in the Mostar facility in 1958. The plant had been designed for the synthesis of all known CW gases to meet the requirements of the Yugoslav Army (JNA). It was equipped with safety and protection devices, detectors and decontaminating agents. Rigorous and continuing training were instituted at the plant.

The plant was comprised of the following: poison gases production facilities, synthesis and analysis labs, underground and above ground storage, test animals (including breeding and rearing facilities), workshops (mechanical, electrical and construction), and, an emergency dispensary.

In terms of administration and R&D, the plant was a branch of the Institute for Technical and Medical Protection in Belgrade. Its average employment was 100 personnel and 95% of the employees were civilian.

During the early stages of the war in Croatia and Bosnia-Herzegovina and knowing that the Mostar CW production facility would fall under the jurisdiction of Bosnia, the JNA ordered the facility to be dismantled and relocated to Lucani in early 1992. By JNA decree, the plant ceased all operations as of 1 January 1992. To preserve the plant’s capabilities, and to ensure the Muslims and Croats did not have future access, all professional papers including studies, analyses, files and records had been taken to Belgrade by July 1991. In January and February 1992, the plant and equipment were disassembled by a group of engineers and technicians from Belgrade.

The JNA Chemical Weapons Development Program

The JNA chemical weapons development program was started with basic/applied research and with limited production of sarin, designated as HM-502 and sulfur mustard designated as HM 501, at a facility within the Prva Iskri complex at Baric. By 1965 the JNA had also begun their in-depth research into the production of sarin and sulfur mustard. Based on this research, designs were made for production of sarin and mustard at 200 kg/day. These programs were completed in the period 1966-69.

By 1970, Yugoslavia had bought and installed production equipment at Mostar with the goal of an annual production of 40 tons of sarin and 30 tons of sulfur mustard. Although chemical research continued towards reaching the production goals as stated, this part of the production facility did not come on line until 1976.

Earlier, in the period 1965-67, a program was also underway for the production of methylphosphonyldichloride (MFDK) at 180 kg/day. This project was completed in 1968 at Lucani within the M. Biagojevic Powder Mill. All three CW plants were undergoing trials during 1969 and 1970.

A phosgene gas line had also been installed at the Mostar facility in 1959 and through 1965 had produced 15 tons of phosgene. In 1965 this whole production line was relocated to the M. Zakic military facility at Krusevac.

During the period 1975-1977, research was carried out on the production of CS tear gas and a 200 kg/day production facility was put into operation in 1978. The technological design included the preparation of CS-1 formula for which a 200 kg/h triturator was procured.

Beginning in 1976, Yugoslavia produced laboratory research amounts of chemical agent for use in testing 155 mm artillery projectiles, MLRS rockets, aerial bombs of various sizes and step mines (sarin filled). The Mostar laboratory was also at this time experimenting with the development of Adamsite, bromosilcyanide, cyanogen chloride, diphenylcyanosarin, chloropicrin and diphosgene and possibly other chemicals. In 1977 a project was initiated to develop a production capability for BZ at 5 kilos per day.

The 1980 to 1984 research programs included BZ and nerve gas production at 5 kg/day and chloropicrin at 10 kg/day. Other nerve gases; soman, VX, tabun, armin, DFP; blister agents, nitrogen mustard, lewisite; and blood agents (cyanogen chloride) were produced in laboratory quantities only.

In October 1993 ASA reported on Krusevac and its related training area of Jastrebac, both in Serbia, and what these locations meant to the CW capabilities picture. The Jastrebac project (1976 to 1988) involved the production of sarin and sulfur mustard for projectile filling and static and dynamic tests performed on Mt. Krivolak in Macedonia. These tests demonstrated the feasibility for introducing chemicals into armaments, i.e., shells, missiles, aircraft bombs and land mines.

The following projectiles were tested within the Jastrebac program: 122 and 155 mm shells, 128 mm missiles, BAD-100 aircraft bombs (smoke bombs) and land or step-on mines. Shells were filled with sarin and mustard; other munitions were with filled sarin. The 152 and 155 mm shells were filled with 3.5 L of sarin or sulfur mustard, 122 mm shells with 1.8 L and 128 mm missiles with 2 L sarin, aircraft bombs with 20 L sarin and step on mines from 0.3 to 0.6 L sarin. Experiments were made with winged missiles filled with 4 L sarin, but, due to problems with rocket motors, further development ceased.

Chemical Weapons Stockpiling Program

Within the Jastrebac program, a CW production facility was put into operation in the 1986-87 time frame. During its trial operation it produced 250 sarin filled 122 mm shells which were put into storage as CW reserve. The 1991-95 production schedule called for storing 4,800 sarin filled 122 mm shells and 1,000 mustard filled 122 mm shells. A planned storage area was built at Hadzici near Sarajevo. For this purpose 40 tons of MFDK, the principal precursor in the production of sarin, was produced in 1988-89. In early 1992, the entire quantity was returned to Lucani. Taken away were also the other precursors needed for synthesis of sarin and sulfur mustard. At the Vogosce UNIS plant, 122 mm shells were made ready for transport to Mostar as early as 1990.

The Yugoslav government had planned for the 1990 - 95 time frame to begin production at annual levels of 3,000 MLRS rockets filled with sarin and one hundred 155mm artillery shells to be filled with sulfur mustard. Additionally some one hundred short range missiles were to be filled with mustard.

This plan was not completed in its entirety and in 1991 destruction of some of the chemical weapons began when the JNA began working on destruction of older stores of nerve agent. During this initial destruction period, some 220 rockets, 15 artillery projectiles and a quantity of unfilled munitions were destroyed.

From January to March 1992, the JNA began work on dismantling their CBW research facility in Mostar, about 40 km southwest of Sarajevo. It was then transported to Lucani in southern Serbia. At about this same time, the four leading civilian scientists and managers working on the CBW programs at Mostar decided to terminate their employment and they left. This seriously jeopardized the ability of the relocated facility to come back on line prior to early and mid 1993, even though all equipment was in place. A caution recognized is that these four individuals may not have been working on the only CBW programs within Yugoslavia, and, perhaps experts from Belgrade were working on other programs, not connected to Mostar. This would have left a cadre of experts who could have initiated the CW programs much earlier.


The former Yugoslav Army did work and perhaps still does work on the synthesis and production of nerve agents, sarin, plus mustard and BZ. Production had been underway for a quantity of MLRS, 155mm artillery, aircraft bombs, spray systems, aircraft spray units and grenades as weapons for these agents. These weapons had been standardized and were ready for distribution. Equipage to the forces had begun on the MLRS, 155mm artillery, hand and rifle grenades. This equipage could be assumed to be still underway. In 1991, and with the onset of war, plans for CW production were severely curtailed.

Some quantities of nerve and mustard agents were destroyed; how much remains is a question. An expert from Belgrade believes nerve agent production could not have been immediately available. However, the assumption held by several of the former Mostar management/science personnel is that the Yugoslavs/Serbians have been and are presently producing at least laboratory amounts of nerve and mustard for testing with all weapon systems. There remains a question as to the Yugoslav disposition of 30+ tons of CH3POCl2 that were sent to Mostar from Lucani and then back to Lucani as the Mostar plant was being disassembled. The production of CS and BZ was reportedly underway in Kruselak, near Belgrade. Hand and rifle grenades for CS have been produced.

All required equipment, documentation and required chemicals for production and weaponization of chemical agents, were relocated to and were supposedly in place at Lucani and Belgrade in 1992. Although several of Mostar’s top managers did not relocate to Yugoslavia, some of the Mostar personnel had in fact done so. The Military Technical Institute, Department for Technical and Medical Protection in Belgrade, had the potential, in conjunction with the returning Mostar professionals, to reassemble the facilities and resume CW production. Was the program reactivated? As of this time, the FR Yugoslavia is one of the very few countries in the world that has neither ratified nor even signed the Chemical Weapons Convention.

Perhaps, with reason.

99-2, issue no. 71

For the Professional in Government and Industry with an interest in Nuclear, Biological and Chemical Defense, Disarmament and Verification; Emergency and Disaster Medical Planning; Industrial Health and Safety; and Environmental Protection
="*%">For the Professional in Government and Industry with an interest in Nuclear, Biological and Chemical Defense, Disarmament and Verification; Emergency and Disaster Medical Planning; Industrial Health and Safety; and Environmental Protection