These Regulations implement in addition to Articles 9 and 11 of Directive 94/62/EC of the European Parliament and the Council on packaging and packaging waste, two Commission Decisions providing for derogations in respect of plastic crates and pallets and glass packaging. Part II provides for the application of the Regulations. They apply to all packaging (reg. 2) other than those excluded by regulation 4. Part III sets out the general requirements of the Regulations. Regulation 5 imposes a duty on a responsible person who places packaging on the market to ensure that it satisfies the relevant essential requirements. The essential requirements are set out in Schedule I. Regulation 6 imposes a duty on a responsible person who places the product on the market to ensure that the sum of the concentration levels of lead, cadmium, mercury and hexavalent chromium of packaging or of its packaging components, which is placed on the market on or after certain dates do not exceed certain limits on a sliding scale. Regulation 7(1) provides for the responsible person to keep technical documentation on compliance with the essential requirements and the heavy metals concentration limits in respect of packaging and to make this available at the request of the enforcement authority for a period of four years from the date packaging is placed on the market. Part IV relates to enforcement of the Regulations.