L 313/12 Official Journal of the European Communities 13.12.2000 DIRECTIVE 2000/69/EC OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL of 16 November 2000 relating to limit values for benzene and carbon monoxide in ambient air THE EUROPEAN PARLIAMENT AND THE COUNCIL OF THE EUROPEAN UNION, Having regard to the Treaty establishing the European Community, and in particular Article 175(1) thereof, Having regard to the proposal from the Commission ('), Having regard to the opinion of the Economic and Social Committee (%), After consultation of the Committee of the Regions, Acting in accordance with the procedure laid down in Article 251 of the Treaty (%), Whereas: (1) On the basis of principles enshrined in Article 174 of the Treaty, the European Community programme of policy and action in relation to the environment and sustainable development (the Fifth Environment Action Programme) (*), supplemented by Decision No 2179/ 98/EC of the European Parliament and the Council (°) on its review, envisages in particular amendments to legisla- tion on air pollutants. That programme recommends the establishment of long-term objectives on air quality. Article 174 of the Treaty requires the precautionary principle to be applied in relation to the protection of human health and the environment. (2)  Article 152 of the Treaty provides that health-protection requirements are to form a constituent part of the Community's other policies. Article 3(1)(p) of the Treaty provides that the activities of the Community are to include a contribution to the attainment of a high level of health protection. (3)  Pursuant to Article 4(5) of Council Directive 96/62/EC of 27 September 1996 on ambient air quality assess- ment and management (%), the Council is to adopt the legislation provided for in paragraph 1 as well as the provisions laid down in paragraphs 3 and 4 of that Article. (4)  Directive 96/62[EC requires that action plans be devel- oped for zones within which concentrations of pollu- tants in ambient air exceed limit values, plus any tempo- rary margins of tolerance applicable in order to ensure compliance with limit values by the dates laid down. () O] C 53, 24.2.1999, p. 8. () O] C 138, 18.5.1999, p. 42. (*) Opinion of the European Parliament of 2 December 1999 (O] C 194, 11.7.2000, p. 56), Council Common Position of 10 April 2000 (OJ C 195, 11.7.2000, p. 1) and Decision of the European Parliament of 6 July 2000 (not yet published in the Official Journal). Council Decision of 24 October 2000. (4 O] C 138, 17.5.1993, p. 5. () O] L 275, 10.10.1998, p. 1. () O] L 296, 21.11.1996, p. 55. (5)  Directive 96/62/EC provides that the numerical values for limit values are to be based on the findings of work carried out by international scientific groups active in the field. The Commission is to take account of the most recent scientific research data in the epidemiological and environmental fields concerned and of the most recent advances in metrology for re-examining the elements on which limit values are based. (6)  The measures necessary for the implementation of this Directive should be adopted in accordance with Council Decision 1999/468/EC of 28 June 1999 laying down the procedures for the exercise of implementing powers conferred on the Commission (7). (7)  The amendments necessary for adaptation to scientific and technical progress may relate solely to criteria and techniques for the assessment of concentrations of benzene and carbon monoxide or detailed arrangements for forwarding information to the Commission, and may not have the effect of modifying limit values either directly or indirectly. (8)  The limit values laid down in this Directive are minimum requirements; in accordance with Article 176 of the Treaty, Member States may maintain or introduce more stringent protective measures; in particular, stricter limit values may be introduced to protect the health of particularly vulnerable categories of the population, such as children and hospital patients. A Member State may require that limit values be attained before the dates laid down in this Directive. (9  Benzene is a human genotoxic carcinogen and there is no identifiable threshold below which there is no risk to human health. (100 However, when limit values for benzene as set by this Directive are difficult to achieve because of site-specific dispersion characteristics or relevant climatic conditions and if the application of the measures would result in severe socio-economic problems, Member States may ask the Commission for one time-limited extension under specific conditions. (11)  In order to facilitate the review of this Directive in 2004, the Commission and the Member States should consider encouraging research into the effects of benzene and carbon monoxide, taking air pollution in enclosed spaces into account as well as that in outside air. () O] L 184, 17.7.1999, p. 23.