# Reaction between lye and water?

I am planning on making some homemade soap soon and have read online that breathing in the fume generated from the reaction between lye and water is not recommended because it is "hazardous."

I am a little bit confused because I thought the reaction between lye and water is simply a highly exothermic dissolution reaction and therefore the "fumes" would consist of only steam?

                           NaOH + H2O -> OH- + Na+ + H2O + HEAT


If this fume is corrosive, does that mean there is some gaseous hydroxide as well generated from the heat? Why else would this fume be dangerous?