The Classification of Non-Tariff Measures (NTM) developed in 2012 by the Multi-Agency Assistance Team (MAST), a working group of eight international organizations, classifies TBT among the 16 chapters on non-tariff measures. In this classification, the OEE is classified as Chapter B and defines “measures relating to technical regulations and procedures for assessing conformity to technical rules and standards, with the exception of measures covered by the SPS Agreement”. Technical barriers to trade here relate to measures such as labelling obligations, standards for technical specifications and quality standards, and other environmental protection measures. Chapter B also covers all conformity assessment measures related to technical requirements such as certification, testing and inspection.  Other examples of TBT are rules relating to the weight, size or packaging of products; standards of ingredients or identity; retention limitations; and import examination and certification procedures. High-income countries tend to have fewer trade barriers than middle-income countries, which tend to have fewer trade barriers than low-income countries.  Small states tend to have lower trade barriers than large states.    The main barriers to trade are agricultural products.  Textiles, clothing and footwear are the finished products most often protected by barriers to trade.  Tariffs have decreased over the past two decades due to the increased influence of the World Trade Organization, but states have increased their use of non-tariff barriers.
 Testing or certification procedures are examples of technical barriers to trade. For example, a Canadian contractor may have a product certified by the Standards Association of Canada (CSA), but this certification may not be valid in other countries. This forces the company to re-certify the product in the country where it wants to sell it, a potentially expensive and time-consuming procedure. The Agreement on Technical Barriers to Trade (TBT) aims to ensure that technical rules, standards and conformity assessment procedures are not discriminatory and do not create unnecessary barriers to trade. At the same time, it recognizes the right of WTO members to implement measures aimed at achieving legitimate policy objectives such as the protection of human health and human security or the protection of the environment. . . .