  An analysis is made of the particle composition in the final state of $pp$
collisions at 7 TeV as a function of the charged particle multiplicity
($dN_{ch}/d\eta$). The thermal model is used to determine the chemical
freeze-out temperature as well as the radius and strangeness suppression factor
$\gamma_s$. Three different ensembles are used in the analysis. The grand
canonical ensemble, the canonical ensemble with exact strangeness conservation
and the canonical ensemble with exact baryon number, strangeness and electric
charge conservation. It is shown that for the highest multiplicity class the
three ensembles lead to the same result. This allows us to conclude that this
multiplicity class is close to the thermodynamic limit. It is estimated that
the final state in $pp$ collisions could reach the thermodynamic limit when
$dN_{ch}/d\eta$ is larger than twenty per unit of rapidity, corresponding to
about 300 particles in the final state when integrated over the full rapidity
interval.
