Heyo. I just use wood chips, but I wanted to address the question of silica. Silica is an ingredient in most sand in most of the world. It's also known as silicon dioxide.
Yes, it's a carcinogen... if you encounter it in certain ways in certain quantities. It's a little like H2O, in this regard. If you inhale H2O, you'll probably die, especially if you inhale a lot of it. Does that make H2O toxic? Well... I mean... it's water, so you kind of have to have it.
Same with silica. You actually eat silica all the time. It's in many of the plants you eat. Science is out on the matter, but it may be that we even NEED silica in our diets.
So, why is it classified as a carcinogen? Because when it is inhaled as a dust, it causes inflammation in the lungs and other parts of the body that can lead to cancer. This is especially a problem in construction fields because many many many building materials contain silica, and during demolition efforts, it is often turned to dust and aerosolized, to be breathed in large quantities by construction workers.
It can be dangerous in other scenarios as well, but this is the most common one.
So, in short, if you are using sand YES there will be silica in it. Sand is simply very tiny particles of stones, and most stone in most of the world contains silica. But it's probably harmless, because your chicks are not going to be turning it into sand dust and then breathing it in. Unless things have changed a good deal since I was last in the incubating/raising chicks business, I don't think they're much into power tools and demolition work.
Your results may vary, of course, but since many experienced folks use sand successfully to raise multiple generations of birds, I strongly suspect the risk is extremely minimal.
Hope that helps!
(Credentials: I don't have any, but I write for an environmental engineering firm, and we talk about the dangers of silica fairly often in their blog, so I have some passing familiarity with when it is and is not dangerous. YMMV, this advice is not medical advice, take what I have to say with a big huge grain of salt and absolutely do not accept my or anyone's advice without doing your own due diligence.)
