Irish researchers found the cocaine was the most adulterated out of 25 countries, packed with a wide range of substitute stimulants.
And not only were cocaine users in Ireland getting the worst product in Europe, they were also paying the most — outside Luxembourg.
In what is the first such research of its type in Ireland, 10 experts attached to the State’s Forensic Science Laboratory examined the purity of both cocaine and heroin between 2010 and 2012.
They also examined street prices for the drugs during that two-year period, using information supplied by the Garda National Drugs Unit.
The scientists at the laboratory selected 217 cocaine cases and 239 heroin cases between April 2010 and March 2012.
It found that the average purity of cocaine was 15% in 2010; 19% in 2011; and 17% in the first three months of 2012. The highest purity was 68%; the lowest 0.2%.
It said there was a large variation in the purity of cocaine, compared to heroin. There was a large number of packs (almost a third) where the cocaine was less than 5% pure, with roughly another third between 16% and 35% pure.
One of the researchers, Hugh Coyle, said there appeared to be two markets for cocaine: “There seems to be two groupings: one with very low purity of less than 5% and another one around 21-25%. That may reflect two markets — one low-quality and one normal-quality.”
Almost all samples contained an adulterant — the majority two or more. They included lignocaine (55%), levamisole (49%), phenacetin (46%), caffeine (44%) and benzocaine (36%).
The research examined street prices — most deals were€50 or on average, €138 per gramme.
Comparing purities across Europe in 2010, it found that Ireland had the lowest out of 25 counties, with most states recording purity rates two to three times that of Ireland.
And when it looked at prices, the trend was reversed, with prices in Ireland two to three times more expensive than elsewhere (apart from Luxembourg).
“When compared to the reported data across Europe, it was found that the Ireland’s mean purity of 15% was the lowest reported,” said the report. “The mean price per gramme for Irish cocaine was €138, which was the second highest in the reporting countries.”
In relation to heroin, it noted a steady decline in purity: from 47% in 2010, to 30% in 2011 and to 24% in the first three months of 2012.
About a quarter of all samples were in the 21-25% range.
The most common adulterants in the heroin were caffeine and paracetamol.
The research said the mean price was €34, which was for a half-gramme bag. The most frequent pack prices were €20, €25 and €50.
Unlike cocaine, the study found that the purity of heroin in Ireland was the second highest in Europe, after Turkey. It was the third most expensive in the 25 countries, behind Sweden and Latvia.
Mr Coyle said they hoped to produce updated purity figures on an annual basis.