An MP is calling on the State Government to make radiation monitoring results public after revelations the Lynas Corporation has been stockpiling rare earth concentrate in Bibra Lake.
The Member for Fremantle, Adele Carles, says the Government is yet to confirm whether monitoring is being conducted.
The Environment Minister Bill Marmion has confirmed the containers have been held at Lynas' holding yard since March.
They are not due to be shipped from Fremantle Port until the second half of the year but Mr Marmion says radioactive levels were low.
The concentrate is mined at Lynas's Mount Weld operation, near Laverton in the Goldfields.
Ms Carles says the Government is basically saying the material is perfectly safe.
"I say to them, well, if it's so safe, then release to us the radiation monitoring so that we can see that for ourselves," she said.
Ms Carles says monitoring is required under a Radiation Management Plan.
"That requires that if this material is stored anywhere for more than 24 hours, there must be radiation monitoring," she said.
"I've asked to get copies of this monitoring and the Minister has basically denied that information."