The substance that brought one of Russia's longest oil pipelines to a halt in April was carbon tetrachloride, a lethal chemical meant to be tightly controlled by an international agreement, according to the results of three separate, undisclosed tests seen by Reuters.
A summary of the results of a test carried out for Russia's Ministry of Energy and for Transneft, the operator of the pipeline, by a Moscow-based state chemical laboratory seen by Reuters in May, which has not previously been reported, shows that the contaminant was 85 percent carbon tetrachloride.
The presence of carbon tetrachloride suggests Russia has not stamped out illegal trade in the chemical, five oil industry sources said. Carbon tetrachloride is supposed to be strictly regulated by Russian law, these sources said.
Russia's Energy Ministry has blamed the stoppage in the Druzhba pipeline on a legally traded solvent called ethylene dichloride, an organic chloride compound used to clean oil wells, which can corrode equipment if it enters a refinery, according to industry experts.
Russia's Energy Ministry and Transneft did not reply to Reuters requests for comment.
Two separate tests performed by two different companies, a European Union refiner and an international oil trading firm - which both told Reuters they unwittingly bought tainted crude from the pipeline — yielded almost identical results to the tests conducted by the Moscow state laboratory, two sources familiar with the findings told Reuters.
The sources asked not to be named as they are not authorized to speak to the media.
Transneft said in June that 200 to 300 tonnes of an unnamed contaminant had entered the pipeline, but has not since made public any further details on the matter.
Russia, the world’s second-biggest oil exporter, lost more than $1 billion in revenue due to the more than month-long stoppage of the pipeline, which carries about 1% of the global supply of crude oil from Russia to refineries in eastern and central Europe. The pipeline fully restarted normal operations on July 1.
Russian authorities are still investigating the contamination, which affected about 5 million tons of oil in the pipeline stretching from Russia to Germany, Poland, Hungary, Slovakia and the Czech Republic via Belarus and Ukraine.
Four people are in custody, suspected by Russian investigators of introducing contaminated oil into the pipeline at an intake station in the Samara region of Russia, while two other suspects have fled the country, law enforcement sources have told Russian news agencies. Two of those held in custody have admitted some wrongdoing, according to their lawyers.
Reuters could not determine exactly how or why the substance entered the pipeline.
Carbon tetrachloride was widely used in the past to make refrigerants, fire-extinguishing materials and cleaning agents.
Its production has dropped sharply since the Montreal Protocol, an international agreement to limit the use of ozone-depleting substances, took effect in 1989.
Under the protocol, which has been ratified by every nation, governments are charged with controlling production of certain chemicals and their compliance is monitored by the United Nations Environment Program's Ozone Secretariat.
Nevertheless, four oil traders in Russia's Tatarstan and Samara regions, where authorities say the tainted oil entered the Druzhba pipeline, told Reuters they regularly obtain carbon tetrachloride to bulk up more expensive bona fide oil products.
The traders, who asked not to be named, said producers of the chemical often give it away or even pay third parties to take it away, making it lucrative to mix with oil and sell the resulting mixture on at a profit.
A spokeswoman for the U.N. Ozone Secretariat said its senior members were not immediately available for comment.
Russia allows only two plants to produce carbon tetrachloride, under quotas approved by the prime minister, to be used as an ingredient for creating other chemicals: the Khimprom plant, owned by Orgsintez Group, in the Chuvashia region, and a plant owned by Galopolimer in Kirovo-Chepetsk.
In each case, any waste containing carbon tetrachloride must be burned and cannot be bought or sold without a guarantee that it will be processed or destroyed, according to Russian law and the terms of the Montreal Protocol.
However, rather than being destroyed, waste containing carbon tetrachloride is being regularly moved across Russia in trains and tanker trucks to unspecified customers, according to five local traders.
Galopolimer did not reply to requests for comment.
Two local traders in southwest Russia said they had bought organic chloride waste from Khimprom to resell and that the chemical company had sent it by truck to the Tatarstan region.
A spokeswoman for Orgsintez Group, which owns the Khimprom plant, said Khimprom does supply carbon tetrachloride to companies that use it to produce titanium, zirconium or as part of other chemical processes, but declined to name any customers, saying that was internal information.
She said Khimprom does not destroy carbon tetrachloride, but receives guarantees from customers to which it sells the chemical that it will be fully processed or destroyed as the law requires.
Rosatom, Russia's state nuclear corporation, which was due to become responsible for chemical waste disposal from July this year under a government act, did not reply to a request for comment.