A senior bureaucrat who helped design the Rudd government's home insulation scheme has defended his decision to allow the use of deadly foil insulation.
Kevin Keeffe, a former assistant secretary of the environment department, has told a royal commission he knew about foil-related deaths in New Zealand from a similar programme.
He also accepted that warnings about the electrical hazards of foil were in an industry pocketbook he authorised to be published in August 2009, a month after the Rudd scheme was rolled out.
But Keeffe said he didn't have the power to overrule more senior public servants.
"Can I remind you of my position?" he said under questioning from counsel assisting Keith Wilson QC.
"You asked me why I didn't challenge fundamental parameters. In terms of roles that were available to me, I was to ensure the quality of the materials were safe."
The former Labor government's home insulation scheme was announced in February 2009 as an economic stimulus measure during the global financial crisis.
The royal commission is examining its failings after the deaths of four installers before the programme was halted after just seven months.
They included two Queenslanders who died while using metal staples to secure foil insulation, a practice that killed three New Zealand installers in 2007.
Reflective foil sheeting wasn't banned until February 2010, five days after Mitchell Sweeney, 22, was electrocuted while installing the product near Cairns.
But metal staples had been banned in October 2009, after Matthew Fuller, 25, was electrocuted south of Brisbane.
"We took the view that metal staples were the problem and plastic staples should be used," Keeffe wrote in a statement to the inquiry.
The inquiry also heard that leading insulation manufacturer, Fletcher Insulation, had circulated an internal email in July 2009 voicing concerns about the safety risks of foil.
"Stapling through foil is an unacceptable risk," the company said.
Keeffe agreed on Tuesday that he was aware of deaths from foil insulation in New Zealand, before the Australian fatalities.
He earlier told the inquiry he didn't anticipate deaths in Australia because the Rudd programme was different to the one in New Zealand, which involved do-it-yourself, under-floor insulation by untrained and unsupervised installers.
The inquiry continues.