The possibility of a chemical reaction near absolute zero has appeared doub
tful: since the beginning of the 1970s. The existing ideas must be revised
after the radiation polymerization of formaldehyde at 4.2 K has been observ
ed. In glassy systems, we have examined chain processes that occur under sh
arp (by five to six orders) changes in molecular mobility of the medium in
the region of matrix devitrification. Quite unusual mechano-energetic chain
s of chemical conversion arise in the studied systems submerged in liquid h
elium. The chemical transformation initiated by local brittle fracture trav
els over the sample as an autowave. A series of experimental and theoretica
l investigations devoted to this interesting phenomenon are described. Ther
e is no generalization in this new region of chemistry up to this time. Man
y journal articles and reviews have been previously published only in Russi
an. The cycles of investigations of chain cryochemical reactions are the su
bject of this review. We hope that the investigation of the extraordinary p
eculiarities of chain cryochemical reactions should produce new ideas in ch
emical theory and industry.