A data processing method for an environmental certification program is provided which defines a plurality of predefined criteria which must be met by a participant in the program in order to be provided with a privilege of providing a certification mark for use on goods and in advertising materials of the participant. The data processing method tracks the compliance by the participant with the environmental certification program, and further evaluates the continued certification of a participant in the program. Preferably, continued certification requires achieving additional predefined criteria while maintaining the predefined criteria which led to initial certification. Moreover, compliance with the predefined criteria is preferably ensured with periodic on-site verification. The predefined criteria preferably are distinguished across several categories and including energy efficiency, the use of renewable energy, recycling, waste minimization, health and safety, reduction of environmental liabilities, corporate citizenship. The criteria for all participants in the program are uniform. As such, the use of the certification mark by a complying participant has discernable value in the marketplace, and the continued display of the certification mark by a participant on its goods and advertising signifies the participant's dedication and actions with respect to environmental concerns.