Yvonne Dalton: "The skin just started peeling away"
A judge is expected to order several retailers to pay millions of pounds to people who suffered burns and rashes from faulty leather sofas.
The BBC now has evidence that Argos, Walmsleys and Land of Leather, accept liability - subject to it being proved that injuries were caused by the sofas.
More than 1,600 people claim to have been affected by the problem.
Tens of thousands more people could have burns not yet traced to sofas.
The High Street stores, along with 11 others may have to pay more than £10m in compensation and legal costs, the shoppers' lawyers say.
They claim that makes it "the largest group compensation claim ever seen in British Courts"
Chemicals used to protect the sofas caused burns
The sofas, which were manufactured in China, were packed with sachets of an anti-mould chemical called dimethyl fumarate to stop them from going mouldy during storage in humid conditions.
Commonly known as DMF, the toxic, fine white powder has been used by some manufacturers to protect leather goods like furniture and shoes from mould. Even very small amounts can be harmful.
One sofa customer who is well aware of the health problems caused by her purchase is Yvonne Dalton, who bought a leather sofa suite from Argos in April 2007.
Almost a year later she started to notice a rash developing on her arms and legs.
After a few weeks her skin started flaking off. She says the irritation was so bad she was off work for two months.
Yvonne was seen by more than a dozen doctors, who couldn't work out what was causing the rash.
She said: "It was very, very painful - I couldn't sleep at night, I couldn't walk about, I couldn't drive, the fact that every time I did walk about the skin would fall off and I would leave a trail of it - therefore I couldn't go to work."
Yvonne was one of thousands of people who had bought a leather sofa from Argos, Land of Leather, or Walmsleys, and then suffered a severe reaction.
For a long time none of those suffering knew it was their sofa causing the problem - so they simply kept sitting on the defective furniture, and worsening their condition.
A dermatologist in Liverpool solved the mystery. After hearing of an increasing number of patients presenting with similar symptoms, the scientist discovered they had all recently bought new leather furniture, which had been packed with chemical sachets in China.
The scientist tested the contents of one of the sachets on his skin, and it quickly reacted.
Further testing revealed that the sachets contained a chemical called dimethyl fumerate - or DMF - placed inside the sofas to stop them from going mouldy during storage in humid warehouses in Asia.
When the sachets get hot, the chemical evaporates into the air - penetrating through the leather and victims' clothing and onto their skin - causing painful blisters and sores.
Richard Langton: "Potentially people are still suffering"
Many people discovered they might have been affected when they saw an investigation on the BBC's consumer affairs programme Watchdog.
Meanwhile several law firms realised there could have been thousands suffering, without knowing the cause of their injuries.
They put advertisements in national newspapers, warning people they may have been affected.
"We advertised in eight national newspapers last October, and purely from those we got another 3,500 people coming forward," said Richard Langton of Russell, Jones and Walker solicitors.
"I think potentially there are tens of thousands more people out there who might be affected - potentially people are still suffering and don't know what the problem is."
Argos, Land of Leather, Walmsleys and 11 other very small shops had sold the sofas. After being warned of the problems, they offered exchanges or refunds to people who complained.
After seeing the effects of the chemical, the European Union is now taking action.
TOXIC SOFA SYMPTOMS
It considers DMF to be so harmful to consumers that it is bringing in a new directive in May requiring all retailers to recall from sale any goods which contain the chemical, and to stop any more hitting the shops.
It also appears to require retailers to remove any goods which contain DMF from people's homes.
EU Consumer Affairs Commissioner, Meglena Kuneva said: "We are absolutely certain that the minor quantities of this product DMF in leather sofas or shoes could cause a terrible allergy and even death. It is very, very, serious, we will not compromise on safety."
Until the directive is introduced and tested, it is difficult to determine how it will affect retailers.
Lawyers hope it will compel Argos and Walmsleys to remove any faulty sofas still in customers' homes. But Land of Leather is in administration, so its customers are unlikely to receive any exchange or refund.
Anyone with any concerns about a sofa they have bought can check whether it is affected by looking on the Russell, Jones and Walker website. They could then contact their retailer, or in the case of Land of Leather, the administrators in charge.
Walmsleys said it would not comment about the case while it was ongoing.
Argos said: "Over the last 18 months there have been issues regarding certain sofas manufactured by a company based in China which were supplied to Argos and a number of other retailers.
"This issue is currently the subject of a group litigation order so we are unable to comment on any individual cases.
This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.