I don't use vermiculite in rooting cuttings anymore but am curious if the dust of vermiculite or perlite is unsafe (like asbestos) if the dust in the air gets inhaled? I always strain the perlite to remove the almost 15~20% perlite dust, and when straining, the perlite dust does get into the air. My concern was raised by the following ad:
SPRING SALE!!!!!!       Vermiculite removal now at $7.50 Per square foot

Akram,
I know Vermiculite can cause cancer but I believe one would have to be in close contact with it for a long time.

There was a subject about it about a year or two ago and it involved workers mining it and cancer. If memory serves me, There was a company in Utah that was being sued by former employees and their families.

I wish I had saved the article.
Maybe someone will look deeper into it and post the results.

Its never been proven that vermiculite can cause cancer.  About 7 years ago this rumor started with no prof and there still is none.  Unless 5 days out of the week you are forced to breath in vermiculite dust for 8 hours, there is no health concern. 
Keep in mind, water, H2O is highly toxic and you can overdoes on it if you drink 5-8 gallons with out adding electrolites.  With that, you keyboard can probably cause cancer and your LCD screen can cause it too.

Bill,

I keep thinking Utah, But did you ever catch that story about the miners and their health issues and tried to connect it to their work place?

That's is what I based my comment on, And only that.
But I will gladly stand corrected.

  I have recently seen a bag of vermiculite that was labeled as asbestos free.  It may not be the vermiculite but depending on the source, the asbestos it may contain.

  Jon L

There was one vermiculite mine in Montana which was found to contain asbestos.  I don't think any vermiculite has been mined there since 1990.  Any vermiculite or Perlite that is available these days is thought to be asbestos free.

Having said that, I find that when I am working with Perlite for some time, my lungs do get irritated from the dust.  I don't think this irritation is any greater than if it were any other dust getting into my lungs, and it does go away within less than a day.

~james

It isn't just asbestos - the fine particles can cause silicosis.  It's a good idea to wear a mask when working with both these products.  You might have to magnify this to read it.

http://www.emsl.com/PDFDocuments/Marketing/EMSL_Silica.PDF

The Perlite and Vermic I buy always say asbestos free. The removal service may be for removing it from your house (walls and attic) because it is/was used for insulation. Any dust is probably cancerous to some extent,  but usually affects people with respiratory problems more than the rest. Also, intensity of exposure and amount of exposure over time are large factors in any carcinogen actually causing the onset of cancer.

I saw a study years ago about lettuce as a carcinogen (tested in mice), but you needed to eat about 100 heads a day for many years.

I buy Perlite from the manufacture.  They have various sizes with silica and a horticultural size that does not contain silica.  Regardless, I too started wearing masks while working with Perlite.  I'm not sure about the silica content of Vermiculite. 

As far as filtering out the smaller particles:  I pour the Perlite between Rubbermaid totes with the wind at my back.  The larger pieces fall into the tote below while the dust blows into my neighbor's yard.

~james

James,

I thought it was Utah but Montana could very well be the place.
It's been so long I just couldn't remember.

Thanks

I'm sorry for not clarifying.  I have been under the impression that the Libby, Montana mine has been shut down since the early 90s (if not before)