A dust cloud which leaked from from Hanson Cement at Padeswood - formerly Castle Cement - in Flintshire, UK is being investigated by the Environment Agency.
The leak was reported by residents in Penyffordd, near Mold on Thursday, according to a news report from the BBC Wales. One man said the leak had covered everything in the village and he was unable to wash the "opaque layer" of dust from his car.
Environment Agency Wales said it had taken almost 30 calls from the public.
"We are conducting our own detailed investigation on site and in the surrounding area of Penyffordd and Penymyndd to assess the impacts of this incident," said an officer for the agency.
"If we discover that there have been any breaches of their environmental permit, we will take appropriate enforcement action against the company."
The company has arranged for villagers affected by the dust cloud to have their cars cleaned.
A spokesman for Hanson said it had received about a dozen complaints from villagers and a number of calls had also been made to Environment Agency Wales.
He said a problem had occurred during the cement milling process on Wednesday evening and this had resulted in cement dust escaping from a storage silo.
"The process was shut down immediately and apart from the environment agency investigating, we’re now conducting our own internal inquiry to find out what went wrong.
"We have been assured that there is no threat to health. It’s a nuisance problem rather than a health issue."