"We believe people working long hours for days on end without a rest is completely unsafe.
"It's bad practice in any industry, but for a hazardous industry like oil refining it is an unnecessary risk.
"We are taking this action solely for safety reasons."
Job security was tied in with union members' resistance to Refining NZ's collective employment proposal, Mr Abbott said.
"The members are also concerned by the company's decision to contract out previously secure jobs. The members of the two unions are making a stand for secure work."
Mr Abbott said the unions and the company have been negotiating since May and workers are willing to accept a nil wage increase, despite the company being majority-owned by profitable oil giants and an intrinsic part of their oil supply chain.
The strike is set down for a 48-hour period starting at 12.01am on Tuesday, October 7.
Most of the 160 workers downing tools are operations, emergency service, mechanical, instrument and maintenance staff. About 500 workers are on site altogether, about 320 of them Refining NZ employees and the rest contract workers.
Meanwhile, the issue of safety during the strike period is paramount to Refining NZ (New Zealand Refining Company), which says action that took 160 workers off the job would force the refinery to shut down for 11 days.
That would be the time it took to close down the processing operation beforehand and a successful restart after the strike, it said.
The loss of income for the company in that period could be as high as $9 million.
Communications and external affairs manager Greg McNeill said Refining NZ will continue to bargain in good faith to reach a settlement with the unions.