A rural West Auckland community says it is worried that plans to expand a nearby factory will mean an increase in deadly dust particles.
The Inpro factory in Waitakere processes volcanic rock known as perlite and makes products used in agriculture and insulation.
It is applying for consent to double its processing capacity from 10,000 to 20,000 tonnes per year.
But one of the factory by-products are small dust particles called PM10, which are so small, the Government says they can cause asthma, cancer and even premature death.
Jan Hendrix lives next to the factory grounds, and said one day in February 2012 there was so much dust raining down he thought a volcano had erupted.
"We were sitting outside and of all of a sudden there was - it was like snow. But it was 25 or 26 degrees outside, so it obviously wasn't snow. It looked like volcanic ash.
"The excuse was that they had a ripped bag.
"The next day we collected a new car for my wife. I washed that car ten times the first week because every time it was covered in rubbish."
He said they took samples from their outdoor table which were shown to be perlite.
Manager of the Inpro site, Matthew Malaghan, said there had been failures in the past of bags which are used to catch the dust.
But he said upgraded machinery, and bags, would mean more perlite could be processed more efficiently, and without too many more PM10 particles escaping.
A report compiled for the resource consent application said there would only be "very modest increases" - but that was not a good enough guarantee for everyone.
Children's health must be first priority
A Labour MP for west Auckland's Waitakere township says the health of local schoolchildren should be the first priority in deciding if a nearby factory can increase processing.
The Labour MP for Te Tai Tokerau, Kelvin Davis, said the children's health needed to be the first consideration in the consent.
"You'd have to be concerned that the fine dust particles could be getting into those kids' lungs - we'd hate to see some kind of asbestos time-bomb ticking for those kids."
The factory is 400 metres from Waitakere Primary School.
It has 480 students. Mother of two of them, Francesca Roehlecke, knows PM10 is already released from car fumes and indoor fires, but does not want her boys to be faced with any more than is necessary.
"The thought of my children going to school right next to a factory that emits this type of pollutant into the atmosphere, and also that it's going into everyone's drinking water supply, is of concern to me," she said.
Waitakere Ranges local board member, Greg Presland, said the Inpro factory has its own industrial class despite its proximity to houses, a school and the Waitakere Ranges heritage area.
"I believe it's got its own zoning, so just that one particular section has a zoning that allows that activity to occur.
"Part of the problem is the historical rights - if someone wanted to set up a factory there now, I doubt they would succeed. But it's because the activity has gone on for so long with the creation of dust that it's tolerated, if you like."
Mr Hendrix believes the best option for the factory would be relocation.
"Really, what we're aiming at is that (Mr Malaghan) goes where the stuff comes out of the ground - Atiamuri - in the middle of the middle of the North Island.
"He can take his factory there (and) there'll be no school close by."
The public consultation for Inpro's plans closes tomorrow.
The application and corresponding documents can be found here Scroll down to 70 Waitakere Road.