The woman leading a review into building regulations and fire safety following the Grenfell Tower fire has "no conflict of interest" over a former role, the government has said.
Dame Judith Hackitt was a former director of the Energy Saving Trust, which promotes insulation containing a foam known as polyisocyanurate, blamed for fuelling the fire.
The government said she was "an independent and authoritative voice".
At least 80 people died in the fire.
The review is separate to the inquiry led by Sir Martin Moore-Bick so will not look directly into what happened at Grenfell Tower in west London.
It will, however, cover regulations around design, construction and on-going management of buildings in relation to fire safety.
Polyisocyanurate (PIR) was one of the "approved products" listed by the Energy Saving Trust while Dame Judith was a director.
The list on the trust's website still includes insulation made with PIR.
In an interview with the Times, she said she had no role in approving products.
Dr Roth Phylaktou, a senior lecturer specialising in fire and explosion engineering, has previously said that the material, combined with the configuration of cladding on the high-rise building, was "optimum for vertical fire spread".
Communities Secretary Sajid Javid appointed Dame Judith to lead the probe last month. Downing Street confirmed she had stood down from her role as soon as she was made chairwoman.
She told the Times she had intended to resign in 2017 but brought the date forward when she was made chairwoman.
On her appointment, the Department for Communities and Local Government (DCLG) published information about Dame Judith's background including her role in EEF, the manufacturers' organisation, but left out her involvement with the Energy Saving Trust.
Speaking to the Times, Sue Caro from the Justice for Grenfell campaign said the Energy Saving Trust had "endorsed... the very substance believed to be responsible for the rapid and deadly spread of the fire at Grenfell" during Dame Judith's time as director.
"A more unsuitable candidate for this vitally important review would be hard to find," she added.
A spokeswoman for the DCLG said: "Dame Judith Hackitt is an independent and authoritative voice in the engineering sector.
"It was determined that there is no conflict of interest and that her previous role at the Energy Saving Trust did not prevent Dame Judith from being appointed chair of the review."
When asked about Dame Judith's biography, the DCLG said it was "not intended to provide a comprehensive list of all the roles she has undertaken".
The scope of the review will be published this summer. An interim report is expected by the end of the year, with a full report due next spring.
The review will report to the communities secretary and the home secretary. It will examine compliance and enforcement issues around building regulations and include international regulation and experience in this area.