Although most (poly)alkenes + OH reactions proceed nearly exclusively by OH-addition, specific biogenic polyalkenes, e.g. alpha -phellandrene and alpha -terpinene, also undergo fast H-abstraction. In this work, quantum chemical CH bond strengths were calculated for selected (poly)alkenes yielding resonance-stabilised product radicals. Available H-abstraction rate data were found to show a manifest anticorrelation with these bond strengths. Nevertheless, it is also concluded that abstraction rates cannot be related uniquely to the C-H bond strengths. The bond strengths listed can provide guidance in constructing atmospheric degradation mechanisms; a semiquantitative discussion is given.