Concern over dangers of 'legal highs'
4 July 2013 Last updated at 10:49 BST
There are calls for the government to bring in tougher laws on legal highs. Police and trading standards say that current legislation does not go far enough and there are worries temporary bans on new substances could actually be making the industry more dangerous.
The UK is the biggest market for legal highs, also known as new psychoactive substances, in the EU.
The government says it is dealing with the problem and is not complacent about the issue.
Tulip Mazumdar reports for BBC Newsnight and Newsbeat.