Festivalgoers can have their drugs tested as part of a controversial new scheme being run in the UK this summer.
Campaigners say malaria medication, insecticide and cement have been found in recreational drugs sold to festival-goers.
The charity is offering on-site lab testing of illegal drugs like cocaine and ecstasy to make sure they aren't mixed with potentially lethal chemicals.
The service is operating at the Kendal Calling festival in Cumbria and promises users can test their drugs-without the fear of prosecution.
Criminology professor Professor Fiona Measham from 'The Loop' said it could save lives.
“We ask them for a very small amount a little scoop of a powder or one pill, if it’s an ecstasy pill and then we’ll conduct various tests,” said Ms Measham.
“It might be that there are contaminants, for example we found that boric acid [a pesticide] has been mis-sold as cocaine and we’ve found 100% concrete being sold as ecstasy tablets.