The deceased was one of three workers who became trapped at the Auburn factory shortly before 9am this morning.
"This is a bad tragedy", NSW Ambulance Superintendent Paul Turner said in a statement, adding they had deployed 10 resources to try and help the stricken men.
The victim is believed to be aged in his 20s or 30s, and his body is still trapped in the six-metre battery shaped tank.
Another worker, 29, was injured while a third man, 28, sustained leg injuries when he tried to save his co-workers at the DIC Australia premises on Chisholm Road.More news: EBay TV advert moves the needle on Pink Christmas Tree sales
Some of the rescuers were experts in working in confined spaces, he said.
"My understanding is that the men were doing maintenance ... inside the Value-Added Tax but there was still ink hampering rescue efforts".
The conditions in the tank were "hot", he said.
"The last person deteriorated on the scene ... multiple ambulance resources [were] inside with the man trying to save his life", Superintendent Turner said.More news: Exxon Mobil Corporation (NYSE:XOM) Stake Raised by NewSquare Capital LLC
Following a complex operation, two men were able to be extricated and have since been rushed to Westmead hospital with leg injuries.
"It is understood that the rescue will be a complex operation and may take four or more hours", the spokesman said in the earlier statement.
'We did absolutely everything we could. We worked as quickly as we could to access these patients'.
NSW Police and WorkSafe NSW will be investigating the incident.More news: THQ Nordic's Next Title Leaks Ahead of The Game Awards 2017
- Firefighters battle Creek fire above Sylmar
- Polish PM resigns after two years in office
- Fergie opens up about her addiction
- Increase in accidental deaths follows spike in gun sales, study finds
- Carragher Insists Coutinho Is Staying Put Following Interviewer's Barcelona Jibe
- Lawsuit: Bryan Singer Sexually Assaulted 17-Year-Old in 2003
- Facebook adds support for live streaming and video chats to Messenger games
- Israel Defense Forces strike Gaza Strip after Hamas rocket attack
- Delphi Technologies (NYSE:DLPH) Covered By Yet Another Research Firm
- Derek McInnes rejects Rangers to stay at Aberdeen