Yup. It’s a fine powder that will get into the air if walked on or near, and causes nasal and lung irritation if breathed in short term - and silicosis if breathed in long term.

Unlikely this length of exposure would result in silicosis probably though.

[http://npic.orst.edu/factsheets/degen.html]

Not really, there are different forms and OSHA recommendations for how much of a safer form should be in the air if you are possibly breathing it your whole working life..

Pets and very small children might get much higher doses being curious and near the floor though.

Have used it to get rid of fleas. The DA dust just lays on the floor - once applied it’s out of the air.

We didn’t wear respirators and I haven’t heard of anyone who does in this scenario.