Claudia Winkleman's campaign to raise the safety standards on children's fancy dress outfits after her daughter's Halloween costume caught fire, has been a success.
Sainsbury's have promised their children's dress up range will meet the same strict fire safety standards that apply to nightwear.
Tesco and Asda will be applying more rigorous testing, and Marks & Spencer will also do so on future lines.
Winkleman sparked debate after her Watchdog appearance found that children's costumes are considered as "toys" rather than "costumes" and don't go through the same vigorous testing as clothes.
Winkleman is pleased with the news, telling The Mirror: "I love Sainsbury’s for it. Others are doing it too. I had to so something.”
Winkleman's eight-year-old daughter, Matilda, suffered horrific burns after her Halloween fancy dress costume caught fire in Halloween 2014.
She said in an interview with BBC 1'sWatchdog: "It was like horrific birthday candles you blow out and they come back. It was really, really fast."
An experiment was completed on Watchdog to see how flammable children's costumes were, which found that when some fancy dress items were lit with a candle, they were set alight in a matter of seconds and began to melt.
At the time, Rachel Burrows from parenting site Netmums said to HuffPost UK Parents: “Selling children’s costumes as toys not clothes to avoid stringent safety tests is appalling. While it may benefit the manufacturer, it has already left children injured and could well lead to a child’s death."
The Watchdog investigation and Winkleman's campaign has proven to be a success.
James Brown, director of non-food at Sainbury's said: “"We have looked at every detail of our children’s dress-up range in creating our new standard and believe that it will be industry-leading.
"This has not been a simple task, but the safety of children is our number one priority and introducing more rigorous safety standards for our children’s dress-up is the right thing to do.
"All clothing carries some fire risk, but we hope that introducing our own rigorous testing standards that test clothes as clothes rather than as toys will be the first step towards safer testing across the industry."
A Tesco spokesperson commented: “There’s nothing more important to us than the safety of the products we sell and we will always act when we hear customers are concerned.
"We’ve re-tested all of our F&F/Tesco children’s fancy dress costumes and can confirm they all meet the legally required toy test and the kids nightwear test – we won’t be selling costumes that do not meet this stricter regulation.”
A spokesperson from Asda added: "While all of our products meet the current industry standards, we are always looking at ways of improving our own testing methods.
"We recognise children’s dress-up costumes are no longer occasional wear and George has already taken steps to introduce an additional test that goes over and above current requirements to ensure that they are fit for everyday use."
M&S told HuffPot Uk Parents: “We do not currently sell children’s fancy dress clothing. However, any future ranges would meet the very high safety standards we set ourselves, which go over and above all the relevant safety regulations.”