I am no chemist and my knowledge of chemistry is very limited I follow this simple guideline -
"All oxidants are corrosive and fumes are toxic."
30% H2O2 is certainly and oxidant.
From Wikipedia -
"Hazardous reactions. Hydrogen peroxide vapors can form sensitive contact explosives with hydrocarbons such as greases. Hazardous reactions ranging from ignition to explosion have been reported with alcohols, ketones, carboxylic acids (particularly acetic acid), amines and phosphorus"
Frithjof Sterrenburg warns of "brewing up" more alarming and messy than dangerous
"Adding hydrogen peroxide to unoxidized material may result in quite severe foaming and even "brewing up" of the lot."
"The most treacherous aspect of peroxide is that "brewing up" may take quite some time (several minutes) to start, when nothing much appears to happen. Then it may chain-react in almost no time to catastrophic intensity."
I have experimented with H2O2 and potassium permanganate as suggested by Raymond's recent post and I can assure you the resulting fumes are unpleasant.
In hindsight my original warning should have been less dramatic.