Gangs in Ireland are selling cocaine mixed with drugs to deworm cattle, anaesthetics and cancer-causing painkillers, research has found.
Analysis by state forensic experts found street seizures of the drug had purity levels as low as 19% outside Dublin and 28% inside the capital compared with 33%-50% purity across the rest of Europe.
Forensic Science Ireland, based at Garda headquarters, revealed that dealers and trafficking gangs were bulking up cocaine hauls with agents like levamisole, which is used by vets to treat parasitic worms but is added to cocaine to improve its potency.
Other additives include benzocaine and lignocaine, which are local anaesthetics used in dentistry, caffeine and phenacetin, a painkiller banned in a number of countries as overuse was linked to certain cancers, the agency said.
Tony Geoghegan, chief executive of Merchant's Quay Ireland, warned that the use of bulking agents was compounding health risks for users and addicts and increasing overdose risk.
"It is the adulterants that cause most of the problems. Most of the injuries we see in the needle exchange are external venal damage leading to serious abscesses and other serious injuries," he said.
Ireland has the third highest overdose death rate in Europe.
There were 220 drug-induced deaths in 2011 - higher than the 186 road deaths in the same year.
Mr Geoghegan added: "In terms of risk of injury and overdose, because of all the adulterants, it increases the risk and also the physical health damage."
The Garda recorded almost 47 million euro worth of drug seizures last year.
That included almost 10 million euro of heroin, about 22.5 million euro of cannabis, cocaine worth 7.6 million euro and MDMA, ecstasy and similar substances worth more than 3.5 million euro.
The Revenue Customs Service said that last year it recorded more than 1,000 seizures of cannabis valued at 12.4 million euro, 92 seizures of cocaine and heroin valued at 6.7 million euro, and more than 3,700 seizures of amphetamines, ecstasy and other illegal substances valued at almost 4 million euro.
Forensic Science Ireland's examination of drugs seizures made last year by the Garda and Customs also showed heroin on the streets of Dublin had a purity of about 33%, and 35% outside the capital.
Forensic Science Ireland said bulk cocaine and heroin seizures in Ireland had purity levels of 40%.
The Forensic Science lab said seizures of cocaine in bales or packs of half a kilo or bigger were found to have an average purity of 71% and at least one seizure contained cocaine with a purity as high as 91%.
It said the worm treatment levamisole was most frequently discovered - present in 73% of samples tested - while it also warned that other powders or products can be used for bulking including sugars or creatine, but they may not be detected.
Heroin was on average 40% pure with some seizures as high as 81% and others as low as 3%.
It found caffeine was the most common bulking agent for heroin - in 81% of samples - while other substances commonly used were paracetamol, in 70% of samples, and other medicines like diazepam, phenacetin and benzocaine.