Will NAO harm surfaces on which they are sprayed ?

Aqueous Ozone is a very strong Oxidiser. However that does not mean it is corrosive or combustible in the aqueous form( ie. A solution in water) . In commercial as well as residential cleaning Applications it is completely safe and would not harm bare skin. Aqueous ozone has been classified as HAZ class OOO.

Protective Gloves or Equipment Not required
Eye protection Not required
Skin Contact Hazard None has been found in the short term
Skin Absorption NO data exists which shows AO is absorbed through the skin
Ingestion No action needed for incidental Ingestion. However NAO is not recommended to be ingested or drunk regularly as a means of treatment or cure for any disease , therapy etc.
Any Special Waste Disposal None Just as Potable Rinse water
Steps to be taken if material is Spilled/Released None, just wipe as normal potable water.