Considering that almost everything - in the right dose - can cause cancer, that is a non-warning put there to satisfy the stupid law that requires the label.

Like any fine particulate, toxic or not, you don't want to breathe much rock dust. In the worst cases, you can get fibrosis/silicosis from the powdered rock if there's enough Si crystals and they evade the lung's macrophages, but you typically need to work in a quarry for that to happen. Otherwise it's quite safe. Wear a mask while applying, wash afterward and no worries about it in your yard once applied.

I just copied this excerpt from The Survival of Civilization.

" �I didn�t have a lot of money, so I kept bugging my dad to order a
few bags,� remembered Jared. �He reluctantly gave in. When the
bags arrived, I sprinkled two tomato soup cans around each baby
tree.� After 100 trees, his bags were empty, so his other 400 saplings
got none.
"The next spring, Jared watched his unfertilized trees grow 12 inches.
But the Azomite-treated trees grew fully three feet in one spring spurt!
In Jared�s years working in his family�s shade tree business, this was
unprecedented beyond imagination! �The results were just amazing!�
enthused Jared. �
"Impressed by these results, Jared bought more to sprinkle around all
his trees . In the family garden, too, where the effect was similar �
bigger, stronger plants, with one further benefit. �The taste of the
vegetables is dramatically different,� reported Jared. �It�s a great
taste!�"

Particles below a certain size tend to get lodged in lung tissue, and remain there, forever. There is likely no asbestos in your bag of rock dust, but other minerals can cause damage, if you breathe in enough material. I can think of several things that will minimize your exposure to the dust. Apply on a day with little or no wind. Apply after a rainfall, or dampen the ground first. You might be able to cover the application with shredded tree leaves or similar mulch, to keep it from blowing away. Use an appropriate scoop, as opposed to pouring from an open bag. Keep your face upwind of the bag. People who mix up small batches of mortar or grout, by hand, over many years of tub & tile work, develop reduced lung capacity. Wearing a good dust mask is reasonable. Maybe you can use it for other projects, like scraping or sanding paint.

lazygarden

I was thinking the same thing. I emailed the company and they responded that they think it is small amount of sand in the mix. It appears that California have issue with sand so I guess it will issue a warning for people who decide to go to the beach where there would be more exposure