harmlessness       
noun [ U ] uk/ˈhɑːm.ləs.nəs/ us/ˈhɑːrm.ləs.nəs/
 无害
the quality of being harmless (= not able or likely to cause harm)
  He doubted claims about the drug's harmlessness. 他对这种药物无害的说法表示怀疑。 
 He protests too much about the harmlessness of screen violence.
 See: harmless
 - More examples
 - For all their harmlessness, extinct volcanoes are still absorbingly interesting natural spectacles.
 - A large cocktail with a flower in it disguises the alcohol and gives it the illusion of harmlessness.
 - Some politicians were convinced of the harmlessness of labour market deregulation.
 - Persuaded of his harmlessness, she allowed him to go with her.