EMS certification schemes assess a company's overall handling of environmental issues. Unlike ecolabels, these schemes do not imply anything about the environmental impacts of companies' products. Rather, they require companies to follow preset environmental principles and guidelines they set themselves as they conduct business. The requirements in such voluntary schemes are often flexible and open to interpretation, and are generally less contentious than ecolabelling schemes.

The ISO 14001 environmental management system standard is one such scheme at the international level. ISO 14001 helps companies track, understand and improve their environmental management. Unlike sector-specific certifications, ISO 14001 does not require specific principles or guidelines to be followed. Companies can "self-certify" compliance with the standard, but most seek independent verification. Critics maintain that ISO 14001 says nothing about a company's environmental performance, addressing only the effectiveness of its environmental management system. ISO 14001 can be useful, however, in that it forces companies to acknowledge and address environmental issues.

Somewhere between an ecolabel and an EMS certification is a new class of sector-specific environmental certifications, such as those that have been developed for the forestry, fisheries, organic agriculture, and tourism sectors. A company obtains certification if an independent auditor finds that it satisfies principles and criteria set out in the scheme. An industry focus allows the scheme's guidance to be more specific than a generic system like ISO 14001. Certification typically allows the company to place what amounts to an ecolabel on its product, certifying compliance.

5.4.3 Ecolabels, EMS certification and international trade