The number of complaints to the NSW agency in charge of workplace health and safety from regional areas was on track for a record high last year, while the number of inspections carried out tracked towards an all-time low.

Despite the surge in complaints not being investigated, the government has no plans to expand offices in regional NSW, according to responses to questions on notice from a budget estimates hearing in October.

But 17 officers, once certified, are slated for regional areas "in response to predictions of significant population growth in regional NSW and a corresponding increase in infrastructure projects".

The number of complaints during the first 10 months of last year from regional areas had reached 4284, and was on track to surpass the previous year's 4776 complaints.

Less than two-thirds of those complaints had been investigated and the 2677 investigations that were conducted was on track to remain below the record-low 3533 inspections conducted the year before.

The Department of Customer Service did not have data "readily available" on the response time for dealing with complaints in regional areas.

"It would require significant resources to source, compile and validate this information. The diversion of resources cannot be supported at this time," the response to questions on notice read.

Opposition Industrial Relations spokesperson Sophie Cotsis says the government "must recognise that many of the industries with the highest work-related serious injuries and fatalities, including agriculture, forestry and mining, are in regional locations".

She says the government "has broken its promise to keep workers safe".

In June, then-Better Regulation and Innovation Minister Kevin Andrews announced the number of inspectors would rise to 370 with the addition of 39 new inspectors.

The $6.4 million spent on new inspectors would lift the ratio to one inspector for every 10,000 workers in line with the UN's International Labour Organisation (ILO) benchmark, SafeWork NSW said in a statement at the time.

Ms Cotsis says that hasn't happened.

"The latest figures (from January 20) show only 308 inspectors were now employed by the agency," Ms Cotsis says.

The other 62 inspector roles were vacant or subject to recruitment.

Some new recruits hired following the June announcement began their training this week, with 10 of them in the initial cohort to be followed by another 14 that will begin training later this month, a SafeWork NSW spokesperson told AAP.

Four more cohorts will begin training in the coming months, with the final cohort to commence on July 25.

SafeWork NSW was created in 2015 as WorkCover was split into three agencies, the others being the State Insurance Regulatory Authority and iCare.

An independent review of iCare and the legislation that created it by Robert McDougall QC last year recommended the responsible minister "conduct, or commission, a public review of that agency's performance of its regulatory and educational functions".