Magistrate Costas Kilias asked Commonwealth prosecutor Matthew Thompson which material was allegedly involved in the incident and was told asbestos.
The man arrested sent 38 parcels, the Australian Federal Police (AFP) allege.
Some 38 parcels were sent to consulates and embassies in Melbourne, Canberra and Sydney yesterday.More news: French Alps rescue: Helicopter pilot's awesome mountainside manoeuvre saves stricken skier
He was apprehended last night at his home, with images obtained by 9News showing police in hazmat gear assessing the suspect's home.
Avan made no application for bail and was remanded to reappear at court on March 4.
"Police have identified all intended recipients and have put processes in place to recover the outstanding packages".
Emergency services were called to French, Greek, Indian, Italian, New Zealand, Pakistani, South Korean, Spanish, Swiss and USA consulates in Melbourne on January 9. Victoria police said they believed the incidents were targeted and did not impact the general community.More news: Australia to Tour India in Feb-March: Full List of Matches, Venues
There has been no evidence yet that the packages were unsafe, but police Thursday said forensic testing was continuing to determine their exact contents. They gave no additional details of how the asbestos was packaged or what the motive might have been.
The first parcel was received at the Argentinian consulate in Sydney on Monday and contained powder in clear plastic bags inside an envelope.
If found guilty he faces a maximum of 10 years behind bars.
"Similar advice was subsequently provided to consulates around Australia".More news: Andy Murray to face Novak Djokovic in practice match before Australian Open
"The note advised missions to handle mail in accordance with their own government's protocols and instructions", a DFAT spokesman said.