The inquiry into sexual abuse in disability services was told that a national system of safeguards under the NDIS is yet to be determined.

Chief executive of provider peak association National Disability Services Ken Baker told the Royal Commission into Institutional Responses to Child Sexual Abuse the growth of the NDIS would create workforce pressures.

"The challenges around workforce are considerable because just as the disability services system will double in size so must the workforce double in size," he said.

"There will be pressure on providers to recruit quickly and to recruit in a context where there are labour shortages.

"The disability service providers will be struggling to recruit the staff they need.

"In that circumstance there is always a risk that they will cut corners and lower their standard of recruitment."

The inquiry heard the structure of the NDIS would lead to greater casualisation of the workforce which Mr Baker agreed posed a risk to people receiving services.

He said it was his experience that disability organisations made every effort to protect clients from abuse or neglect.

"All the service providers I have ever met have a sincere intention to protect the people to whom they're providing support but in some cases they need to be better equipped to know how to apply that intention," he told the hearing.

"You can teach skills but you probably can't teach values and attitudes. Recruiting people with the right values and attitudes is critical."

Southern Cross University child protection expert Sally Robinson told the commission she was concerned about the lack of incentive for staff training under the structure of the NDIS, which started to roll out nationally this month.

"One of my worries about the NDIS is it's got an opt in system for providers to choose to provide training for their staff," she said.

The NDIS will provide support for 460,000 Australians with disability, including 160,000 children, as it rolls out over the next three years.

Jane Rosengrave​, who has a mild intellectual disability, told the hearing she was sexually abused as a child in institutional care but felt unable to report it.

The commission heard children need independent advocates to support them if they want to complain.

"There should be some advocacy stuff going on in these institutions as well to teach people that they have rights, they can stand up for themselves, they can go to people if they want," she said.

The hearing before Justice Jennifer Coate​ is expected to conclude on Friday.

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