In the morning the boy's father went to his room and found him in exactly the same position but it appeared he was dead.
A pathologist found the boy had inhaled butane gas which caused a cardiac arrest and ventricular fibrillation.
Initially, butane was not suspected and it was not until the ESR report and the full pathologist report was available that the cause of death was established.
Dr Bain found there was no suggestion the teenager was intending to take his life.
"It seems clear that it is an unfortunate combination of events and perhaps a misplaced view that he might obtain euphoria from the use of butane," Dr Bain said.
The teenager had had some heart issues when he was younger but by the time he was 16 there were no significant medical issues.
He was a smoker and a cigarette lighter and packet of tobacco were found in the pocket of his jeans on his bed. Sometime after the boy's death, his father found an empty aerosol can of deodorant in the boy's bedroom. The father had been concerned as he had been with his son when he bought the deodorant a week earlier and he thought the use of it was excessive, given it was empty when he found it.
Specialist evidence that one "huff" from a cigarette lighter or the deodorant canister may be enough to kill someone, especially for a person new to huffing.
ESR was unable to establish whether the butane had come from the cigarette lighter or the deodorant canister.
"In respect of the cigarette lighter it is as simple as pressing the button down and not igniting the flame."
Long term abusers of butane can suffer memory loss, disturbed sleep, depression, personality changes and anxiety. There is also an increased risk of cardiac failure.
Huffing was a very serious problem in New Zealand and since 2000 there had been 63 deaths from the practice. Of those 75 per cent were males and most were under 24.
"These statistics are frightening and decisive action is required to help reduce these entirely preventable deaths of New Zealand's young people," Dr Bain said.
The Chief Coroner had previously recommended several options to help curb "huffing" including a national education campaign, increased publicity and introducing age restrictions with several retailers voluntarily implementing their own restrictions.
"It seems to the court that the matter is one of education and responsibility... The dangers of the practices do not appear to be fully appreciated and that is why an educative programme is, in the court's view, probably the most instructive way of getting the necessary messages through in an educative way, and in a way which stressed harm prevention," Dr Bain said.
Dr Bain has recommended his findings be forwarded to the Ministers of Youth Affairs, Social Development and Health for them to take action.
Signs your child may be huffing
* Chemical smell on their breath of clothing
* Empty canisters in their room or where they spend their time
* Mood swings or a general change in behaviour not explained by normal teenage behaviour
* Changes in eating or sleeping patterns
* Mixing with a new group of friends, especially if they hang out in secluded places
