The union representing the territory's large nursing workforce has called for a review of rosters after complaints about staff being asked to work non-standard shifts without enough notice.

The ACT branch of the Australian Nursing Federation asked for the review to extend not only to Canberra Hospital workers but also to Calvary Public Hospital staff.

Calvary deals with about 30 per cent of the public workload in Canberra.

The union made the request at a regular meeting on Wednesday with ACT Health.

Standard shifts run for eight hours on day and evening shifts and 10 hours at night, while examples of non-standard are staff working six hours during the day or eight hours at night.

''We've had a number of members say they've had a roster come out and it's had six-hour (day or evening) shifts,'' said the federation's ACT branch secretary Jenny Miragaya.

She speculated it might have been a money-saving exercise by ''getting someone to work six hours instead of eight''.

There are an estimated 2000 public nurses across the ACT.

The territory government is working out how to deal with public health costs, which are fast consuming the ACT budget. The ACT's health bill is $1.3 billion a year, or a third of the total budget, and rising.

It has been growing at 7 per cent a year for the past decade and Chief Minister Katy Gallagher has already labelled this unsustainable.

An ACT Health spokeswoman said the directorate had already agreed to do surveys at least every year of staff and reviews to ensure compliance with the employment agreement.

''Nurses are occasionally being asked to work a six-hour shift (a non-standard shift) on a morning or evening to ensure that their full-time equivalent hours are being rostered and worked,'' the spokeswoman said.

''Non-standard shifts are used only when a nurse requests to work less night-duty shifts than the four that are allocated for full-time staff.

''In order that a nurse work their correct full-time hours, the other hours worked to meet that full-time status will be a combination of standard eight-hour shifts and a non-standard six-hour shift.

''Part of the enterprise agreement allows nurses to work 10-hour night duty shifts.

''Generally, to complete full-time hours when night duty is worked requires a nurse to work four 10-hour night duty shifts totalling a full-time roster of 40 hours a week.

''When the request to do less night duty shifts is submitted, the nurse and the manager discuss the proposed rostering of the non-standard shift.

''It is important to note that managers try extremely hard to meet the requests of staff for special rostering, to allow for a better work-life balance … and this will on occasion, create a breach to the EBA because of these special requests.''

The spokeswoman said a recent survey indicated the majority of nurses were very satisfied or reasonably satisfied with their rosters.