Body scanning equipment will be rolled out to all Australian international airports from November, despite lingering concerns about their effectiveness.
The security machines, costing $230,000 each, produce a generic outline of the human body and reveal metal and non-metal items under clothing. They have already been trialled in Melbourne and Sydney.
After new laws were passed by federal parliament on Wednesday, Transport Minister Anthony Albanese reassured airline passengers worried about privacy issues that images won't be copied or stored.
"The millimetre-wave body scanners are perfectly safe and one body scan emits 10,000 times less frequency energy than a single mobile phone call," he said in a statement.
But the Australian Greens warned the machines could lead to a false sense of security.
Greens senator Lee Rhiannon said benign metal objects like buckles, watches, hair clips, studs and zippers could trip alarms and that half of the travellers scanned during trials in Sydney and Melbourne had to undergo further searches.
"It comes back to how we ensure that the safety measures being put in place for air travel actually work and don't result in a false sense of security," Senator Rhiannon told parliament.
"This bill could be giving a false sense of security."
Senator Rhiannon had moved an amendment to allow people to opt out of screening and choose a frisk search as an alternative, similar to measures in the United States, but this was defeated by government and coalition senators to pass the legislation.
The government has already said people with legitimate health or other reasons, such as having pacemakers or being confined to wheelchairs, would be able to avoid the scanners.
Liberal senator David Fawcett said the need for scanners arose from an incident in 2009, when a terrorist evaded security to smuggle a bomb hidden in his underpants onto an aircraft travelling from Amsterdam to Detroit.
"Because they weren't metallic, none of the existing procedures actually picked up those explosives," he told the Senate.
The federal transport department has previously conceded the scanning process takes longer than traditional metal detectors.
The Aviation Transport Security Amendment (Screening) Bill 2012 mandates the use of body scanners to check airline passengers, on the grounds it will provide optimal security with minimal impact.