International frequent travellers might as well start to practice the feeling of being bodily scanned by a $230,000 worth security machine as Australia starts to roll-out those humongous equipment effective November 2012 in all its international airports.

This, despite massive questions against the machine's effectiveness to detect harmful gadgets or explosive devices.

"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,'' Transport Minister Anthony Albanese said in a statement after the Aviation Transport Security Amendment (Screening) Bill 2012 was passed by federal parliament on Wednesday.

Under the bill, the use of body scanners is mandated to check airline passengers on the grounds to provide optimal security with minimal impact. This new law was prompted by a 2009 incident when a terrorist, able to evade routine security inspection, effectively smuggled a bomb hidden in his underpants onto an aircraft travelling from Amsterdam to Detroit.

The security machines, already tested in Melbourne and Sydney, produce a generic outline of the human body and will reveal metal and non-metal items under clothing.

The suspect in the 2009 incident carried a bomb made from non-metallic materials.

But opponents remained skeptical of the new security undertaking, labeling it could only give a "false sense of security."

"This bill could be giving a false sense of security," Greens Senator Lee Rhiannon said, noting the alarm could immediately sound off at the slightest detection of benign metal objects like buckles, watches, hair clips, studs and zippers, causing travellers 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,'' Mr Rhiannon told parliament.

Moreover, travellers would need to allot more time going to the airport to have an early check-in because the scanning process takes longer than traditional metal detectors.

Earlier, the Government has already said people with legitimate health or other reasons, such as having pacemakers or being confined to wheelchairs, would be excused to go under the scanners.