Harmonizations means the establishment, recognition and application of common sanitary and phytosanitary measures by different countries. The SPS Agreement encourages governments to establish national SPS measures consistent with international standards, guidelines and recommendations. The international standards are developed by leading scientists and governmental experts in the field of health protection and are subject to international scrutiny and review.

International standards are often higher than the national requirements of many countries, including developed countries, but the SPS Agreement explicitly permits governments to choose not to use the international standards. However, if the national requirement results in a greater restriction of trade, a country may be asked to provide scientific justification, demonstrating that the relevant international standard would not result in the level of health protection the country considered appropriate.