What it does

Nitrous oxide is a short-acting dissociative anesthetic. A single inhalation lasts about 30 seconds. Medically safe when used with oxygen; recreationally the harms come from repetition, oxygen deprivation, and B12 depletion.

Safer-use principles

• —Never inhale directly from a large tank or a bag over your face — people die from suffocation this way.
• —Sit down. Falls are the most common injury.
• —Do not use frequently. Repeated use depletes vitamin B12 and can cause permanent nerve damage (numbness, weakness, difficulty walking).
• —Cracking chargers releases very cold gas — frostbite of the lips and airway happens.

Dangerous combinations

Combining with other depressants or dissociatives increases the risk of blackout and choking. Driving is impaired even between hits.

If something goes wrong

Loss of consciousness, blue lips, seizure — call 911, remove any bag/mask, get them to fresh air. Persistent numbness, tingling, or difficulty walking after use is a B12-deficiency emergency.