On 2 July 1991 the Commission submitted a proposal for a Council Directive on air pollution by ozone (COM(91) 220). The proposal concerns tropospheric ozone, i.e. that present in the lower layer of the atmosphere. Objectives comprise: Establishment of a framework for the monitoring of ozone concentrations; creation of a forum for the exchange of information between the Member States, the Commission and the European Environment Agency in order to establish a pool of knowledge concerning the problem; provision of information for the public in cases where ozone levels may constitute a risk to public health. The approach selected by the Commission is in two stages: the second stage, already provided for in the proposal, involves the possibility of setting limit values to be met by the Member States.