A NELSON mother of five suffered carbon monoxide poisoning when a chip pan fire, burnt itself out and the fumes overwhelmed her, an inquest heard.

Maureen Collier, 37, was found dead at her sister's house in Claremont Terrace at around 9.30am on August 14 when a builder who had arrived to carry out work at the house found the front door open.

John Hardacre said he had noticed washing on the line, the door was open and a dog came across the yard to him so he presumed the occupant was up.

When he put his head round the door he realised there had been a fire in the kitchen.

He found Mrs Collier's body between the kitchen and living room and asked neighbours to contact the emergency services.

He said: "I realised the landlord had said she was a single mum so I went upstairs to look in the wardrobe and under the bed to see if her children were there. As I came down the stairs I felt heat and noticed the stove was on under the chip pan so I turned it off and went outside."

Coroner Richard Taylor recorded a verdict of accidental death after listening to further evidence from pathologist Dr Charlie Wilson, PC Stephen Rothwell, who was the first officer at the scene, and Nelson Fire Station Commander Nick Isherwood.

Dr Wilson said Mrs Collier's blood contained 240 milligrams of alcohol per decilitre -- the equivalent of three times the drink drive limit -- and she would have been significantly impaired.

He said she had been alive while the fire had been in progress and had breathed in a fatal level of the carbon monoxide fumes.

Mr Isherwood arrived at the house at 10am and said he noted that the fire had centred around the cooker where there was the remains of a steel chip pan and the ring of the cooker had been in the on position.

He said: "A fire had occurred some time previously and consumed all the oil and fat in the chip pan and burnt itself out consuming all the oxygen in the room. Both doors externally and through to the living room and all the windows had been closed in effect creating a sealed environment.

"The assumption is that she had been alerted to the fire and had opened the door from the living room in to the kitchen and had been overcome by the fumes. It is certainly not uncommon for fires of this type to burn themselves out like this."

He believed the dog which was in the house when the builder arrived had managed to open the door itself after the fire.

Mrs Collier, who had five children between the ages of nine and 16, had lived in both Colne and Nelson and had been staying at her sister's house for a short time before her death.