Obviously you want to avoid breathing the airborne dust while mixing, but I wouldn't be too concerned with toxicity, especially in the relatively low quantities that home darkrooms use. Once it's mixed and dissolved fully, you obviously don't want to ingest it or get it in your eyes. Some folks may have a reaction with skin contact, so gloves would be recommended if that's the case for you.
I heat distilled water on the stove to the proper temp for mixing the stock solution, which goes into a plastic mixing bucket and the powder is gradually poured in while mixing the solution. This helps to minimize airborne dust. This is done outside to avoid the powder getting on any work surfaces, and some folks wear a mask to keep from breathing any in. Don't stir too rapidly or try shaking the container, you want to avoid mixing any air into the solution as this can affect it's shelf life. Just keep stirring and the powder will eventually dissolve.
I frequently rinse my hands during development if I touch any chemicals, but this is mostly to prevent any cross-contamination. Obviously, you want to ensure any darkroom chemicals are stored where children can't reach them. You can also try using HC110, which is a liquid concentrate developer and has an extremely long shelf life. No issues with airborne dust while mixing and just as versatile as D-76.