Abstract: A novel polymerizable composition, which can be used in 1K aerosol can systems for forming a foam, include a reactive precursor mixture, which is subjected to one or more deoxygenation measures so that it does not react during storage, and an alkyl metal compound, such as an organic borane compound as initiator. Since the initiation of the polymerization is enabled by oxygen, particularly oxygen from ambient air, the curing of the composition is not dependent on ambient moisture and proceeds even at low temperatures, including those below 0° C. The composition has a fast curing time when contacted with oxygen or air, and the resulting final cured product has a high quality.