The creator of Fireman Sam has said he "can't see" how the children's show has a stereotype problem and puts women off joining the service.
It comes after senior fire officer Alex Johnson told the Daily Telegraph "most of the job is nothing like it is portrayed" in the show.
It has sparked debate on social media about whether the show is sexist.
David Jones, who created the show set in the fictional Welsh town Pontypandy, said there was nothing he would change.
Ex-firefighter Mr Jones, 74, began working on the idea for Fireman Sam - Sam Tan in Welsh - in the 1980s after he heard Mike Young on BBC Radio 2 talking about his cartoon project SuperTed.
"It is for children. It wasn't meant to be advertised as a recruiting post," he said.
"Someone doesn't join the fire service when they watch Fireman Sam. They wouldn't be the right people for the job if that was their mentality."
Mr Jones sold the programme, illustrated by Rob Lee from Cardiff, to Mattel in 2002.
Ms Johnson, temporary deputy chief fire officer for South Yorkshire Fire and Rescue Service - who is campaigning to attract more women into the fire service - said that women and people from different backgrounds do not consider the role because "they aren't seeing themselves represented".
Data shows that 5.2% of firefighters in England are women and 3.9% are from an ethnic minority background, according to the National Fire Chiefs Council.
Meanwhile, the London Fire Brigade, using #FirefightingSexism in its campaign, tweeted that the involvement of Penny Morris, a firefighting character in Fireman Sam, was "devalued".
Sadly Penny’s involvement in the show is completely devalued by the constant use of the outdated term fireman in the catchy theme tune, title and on all merchandise. Language matters #FirefightingSexism https://t.co/ZC55Ujq0FX— London Fire Brigade (@LondonFire) March 18, 2019
Mr Jones maintains there is "nothing he would change about" the show and said that in his 14 years as a firefighter, rushing into buildings on fire was "part of the job".
"A fireman is someone who runs into fire or towards danger when other people run away," he said.
"There has been no harm done from Fireman Sam, it has only done good and I am very proud to have created it."
The show was broadcast for the first time in November 1987 on Welsh TV channel S4C and is shown in more than 155 countries across the world.