Yes!
Mycorrhizal fungi are completely safe.
They are the basis of soil health (and plant health) in every undisturbed ecosystem on our planet. You and I (and everyone who has ever lived on this earth) have coexisted with Mycorrhiza from the start of time - they will do you no harm.
When you go for a hike in a forest, you and I always feel better, and all the soil around you is filled with mycorrhizae (and countless of other types of fungi and bacteria).
However good they are for plants, mycorrhiza are not food for you and I - so, do not ingest Transplanter
After handling the powder, do not touch your eyes or your mouth without washing your hands first. If you accidentally touch your eyes, you may experience some irritation. Simply flush your eyes with warm water and you should be fine.
If you follow these simple safety measures, the only problem you’ll have will be finding enough time to enjoy your beautiful, healthy garden.