Workers at blood and vaccine manufacturer CSL are threatening more industrial action over pay and conditions.
Around 50 workers took strike action last Thursday and are pledging to take a second 24 hour action tomorrow.
It came after negotiations broke down with CSL at its Broadmeadows site in Victoria.
On top of the work stoppages, the employees have also pushed for a ban on international blood processing at the site
According to the National Union of Workers the striking employees have ensured that their action will not risk supplies to critical blood products.
The strike action comes as negotiations breakdown over a new EBA.
Pay has been a major factor with workers pushing for a 6% increase over three year, however according to the AFR management has offered an increase of 3.75%, 3.5% and 3.5%.
Aside form pay workers are also pushing for better conditions at work, including the continuation of 12 hour shifts and for the company to continue to provide thermal socks during work.
"CSL Operators have worked 12 hour shifts for 20 years, the company wants to get rid of this, but many workers have their lives planned around working 12 hour shifts and members do not want this taken away from them," the NUW explained.
The AFR reports that CSL was 'disappointed' by the workers' strike action.
"We have been negotiating since April and we have put [forward] what we believe to be a very fair and competitive offer," CSL spokesperson Sharon McHale said.
She added that the company is aiming for an end to negotiations by the end of the month.