Proton-proton total cross section at cosmic ray energies

New experimental data on proton-proton total cross sections sigma _pp^T at ISR and cosmic ray energies up to about 100 TeV suggest that sigma _pp^T continues to increase with energy as ln² s. The existing data on sigma _pp^T obtained from air shower experiments are discussed in relation to the recent results on primary cosmic ray composition. It is concluded that EAS related results on sigma _pp^T do not provide reliable information about the energy behaviour of sigma _pp^T at energies above 10⁵ GeV.