The concerns have come to light as the consortium responsible for residential care in the ACT says there is "generally no minimum qualification" needed for youth work roles.

Premier Youthworks is a for-profit company that cares for around 30 children across 15 properties in the ACT.

The company said their diverse workforce was an "asset", and that no single youth worker was ever left in charge of any care home.

Children and teenagers wind-up in Premier's residential care homes when they are unable to live with their families, often because they are at risk of abuse or neglect.

Earlier this year a Premier Youthworks staff member had to lock herself in an office when a boy in her care, known as A, and his younger sister, known as B, violently threatened her.

"On 16 February 2017, an argument broke out between a residential youth worker at Premier Youthworks [and] A and his younger sister, B," read a Supreme Court judgement from August this year.

"The youth worker confronted B, who responded with threats of bashing and stabbing her if she called the police.

"A intervened and said, 'I have a f---ing meat cleaver', which he revealed to the youth worker.

"He threatened to stab her if she called the police."

The youth worker locked herself inside an office and called the police, while the two children drove away in a car belonging to Premier Youthworks, according to the court judgement.

"B picked up a petty cash tin which contained the keys to the Premier Youthworks vehicle and a petrol card," the court's judgement read.

"It also contained an EFTPOS card and about $20 in cash. A deliberately blocked the youth worker's view of B, allowing B to run from the room with the tin."

One former staff member said Premier Youthworks employees were sometimes left to run residential homes housing teenagers only a few years younger than them.

Most of the staff members were younger than 30 and many were under the age of 24, the former staff member added.

"You have kids looking after kids. It's absolute madness," they said.

"They are meant to be doing the domestic duties once the kids go to school."

Premier Youthworks chief executive Jared Gillard, a former youth worker himself, said there was not necessarily an issue with younger staff looking after traumatised children.

"I was in my early 20s when I was in charge," he said.

"I don't think it's a prerequisite to have your own kids, but in saying that no single person is responsible for any home."

Premier Youthworks director Lisa Glen added that the company's "diverse workforce" was an asset.

"There's lots of support for the staff there and we also provide a thorough induction program and ongoing training," she said.

"A lot of the people that come and work for us have worked in other areas as well, they bring life skills with them, and sometimes it's not about the age or their qualification."

Premier Youthworks provides out of home care services under the ACT Together consortium, which is funded by the ACT government and led by the Barnardos charity.

Premier declined to answer specific questions about its ACT operations, instead directing them on to Barnardos.

A Barnardos spokeswoman said there was "generally no minimum qualification" required to work in residential care.

"Currently two thirds of PYW staff across NSW and the ACT have a Certificate IV qualification or above," she said.

"PYW is striving to ensure all staff have a Certificate IV in community services as a minimum qualification."

Such certificates typically take at least a semester of full-time study, and can only be achieved after gaining prior qualifications in community services.

The Barnardos spokeswoman said all Premier Youthworks employees were trained intensively before starting employment.

"PYW has a diverse workforce at all levels in regard to age, experience and qualifications and people from respected professional backgrounds including teaching, nursing and policing," she said.

"Further, PYW puts staff through intensive in-house training at the start of employment.

"And [they] have recently appointed internal learning and development facilitators to support ongoing in-house training to ensure staff are prepared for working with children and young people who have experienced trauma abuse and neglect."

Premier Youthworks also operated a 24/7 hotline to help staff with any issues in the residential homes, the spokeswoman added.

A spokesman for the Community Services Directorate said all youth workers in the ACT were suitably trained and qualified.

"Further training is being delivered across the sector to provide those working with children and young people the skills and knowledge to deliver trauma-informed care," he said.