The encyclopedias call him a physicist-chemist and a Hero of Socialist Labor, and say that his main works were dedicated to the study of aerodispersed systems. If translated into an understandable language it means that he was the greatest specialist in dust particles and droplets flowing in the air. He invented the famous PF – the Petryanov filter, which captured everything harmful, even radioactive dust. It turned out that this material is also capable of dampening noise. Igor Vasilievich personally made plugs from it: he came up with the name berushi (“earplugs”) – compiling it from the words beregite (“take care of”) and ushi (“ears”). It is Igor Vasilyevich who is to be thanked for saving pilots, miners, tractor drivers and mechanics from going deaf. And hundreds of thousands of inquisitive people should say thank you to Petryanov-Sokolov for the most interesting magazine Chemistry and life, which he founded and was the head of. A good academician Petryanov-Sokolov did a lot of good things as the chairman of All-Union Society of Book Lovers. He fought for the purity of the air in all senses possible: and in the sense of the air of culture too. He founded movement for the preservation of the monuments of the Fatherland – he fought for this and won. The restored monuments of the Fatherland are still standing – this is a real monument to this remarkable Russian scientist.