I know it's hard to believe, but there is a lot of inaccurate information on the internet, and there are a lot of people who are perfectly happy to spread it. Diatomaceous Earth is obviously not immune from this phenomenon. I often see people make claims about the safety of Diatomaceous Earth that just aren't true, or are at least incomplete. The problem is that there are two commonly used forms of Diatomaceous Earth, Food Grade and Pool or Filter Grade. Food Grade DE is perfectly safe to use around the house and even to occasionally inhale, while Pool/Filter grade is very dangerous to breathe and can cause permanent damage to your lungs.
Both forms of Diatomaceous Earth are made up almost entirely of silica, but Pool Grade Diatomaceous Earth has been heated to produce crystalline silica, which is great for filtering liquids but is very damaging to our lungs when inhaled. Food Grade Diatomaceous Earth on the other hand, in order to be called Food Grade, must be made up mostly of amorphous (unheated) silica and contain less than 1% crystalline silica. Our Vi-Olivia Diatomaceous Earth actually contains half that level of crystalline silica, or 0.5%.
Although Food Grade Diatomaceous Earth is non-toxic and will not cause long-term damage to your lungs, it is a very fine powder and can cause lung irritation when used in a room without proper ventilation. We recommend using a mask when working with Food Grade DE in close quarters or when using for an extended period of time, especially if you are sensitive to dust.