Ash Grove Cement Company has confirmed that all tests conducted on the cement manufactured at the company’s plant outside of Helena, Montana, are negative for asbestos contamination.
Company spokeswoman Jacqueline Clark says the test results are from an independent laboratory.
Ash Grove still needs to conduct additional testing in the coming weeks. At issue is whether the mineral found in the company quarry was correctly identified as tremolite, a deadly mineral used in the production of asbestos.
It is hoped the company will reopen in April.
The testing includes work by the U.S. Mine Safety & Health Administration and the Montana Department of Environmental Quality.
The plant and quarry were shut down on the 16th, and workers were sent home. Workers have been paid in full from the 16th until the 27th of March, but will receive no further monetary compensation for time lost until the plant re-opens. Workers will not be able to return to their jobs until testing is complete and the company is assured that their employees will be able to work in a safe environment.
Tremolite is a type mineral commonly used in the production of asbestos. The company has not verified that the substance is actually tremolite and are waiting on verification from the people performing the analysis on the quarry. If inhaled, tremolite particles may be hazardous to a person’s health. How much damage is caused by tremolite is dependent on how much tremolite has been inhaled.
Tremolite is a mineral that ranges in color from a pure, creamy white to white with green stripes. Inhalation of this mineral has been linked to asbestosis, lung cancer, and mesothelioma.

