Quick guide to... Laughing gas

• Although sold legally for food-related purposes, such as making whipping cream, the government classes it as a volatile substance because it can be used for inhalation as a recreational drug. The use of nitrous oxide as a recreational drug started in the UK in the late 18th century, when the upper classes staged "laughing gas parties". It is sometimes called "hippy crack" due to its addictiveness and the sense of euphoria and sensory distortion that users feel.
• There were reports that some nightclubs were selling the drug during 2007, however such reports have dwindled over the past three years after regulator The Medicines and Healthcare Products Regulatory Agency pointed out that venues could face legal action. Anyone selling laughing gas knowing it will be used for inhalation as a recreational drug could be breaking the law.
• Laughing gas is potentially deadly, with the most recent figures from 2007 showing that three people died from asphyxia after taking the gas.
• The euphoria that users experience is caused by reducing the level of oxygen to the brain.
• This can cause asphyxiation and injury as users typically collapse when inhaling. Long-term, the drug can poison the central nervous system and damage a user's bone marrow. Such problems can be accelerated if combined with alcohol or other drugs.

3 people died from inhaling laughing gas in 2007
1799 the first reported use of laughing gas as a recreational drug
£2 how much one nitrous oxide-filled balloon can cost at a
nightclub

Source: The Medicines and Healthcare Products Regulatory Agency, Drugscope