Developing and implementing an environmental management system lies at the core of the requirements for an ISO 14001 certification.

ISO 14001 uses the standards as a tool in developing an Environmental Management System. Third party certification to ISO14001 carried out done by an accredited certification body. An organization can achieve conformance with ISO 14001 either through self-declaration or through third party registration. The majority of organizations that have implemented ISO 14001 to date have chosen the latter course, mainly because of the greater level of credibility associated with third party verification.

Thus, a trusted non-partisan third-party can review the EMS, but it is not necessary to go through the formal third-party certification. Many organizations also face what is called the Audit Fatigue Syndrome (AFS) in seeking or requiring to gain ISO 14001 registration.

To encourage local governments and related entities to formally register may scare some of them off due to the high cost. Some local governments and utilities are adopting self-declaration or self-certification. Self-certification is a more practical use of ISO 14001.

While credibility and consumer confidence may be important for a company or business to seek accredited third party verification, local governments are influenced by other factors Esuch as political accountability, transparency in decision-making, working for the public good etc. that is more suited to reliable self-declaration.

Indeed, the ISO 14001 standard does not necessarily require third party registration. Under "Scope", it says the standard is "applicable to any organization that wishes to...make a self-determination and self-declaration of conformance with this International Standard." There are potential benefits to third party registration that each entity must consider.

ISO 14021 on "Terms and Definitions for Self Declaration of Environmental Claims." also helps shed light on the issue of Self-Declaration.