The chemical industry (industrial chemicals, pharmaceuticals, pesticides, biocides, food and feed additives and cosmetics) is one of the largest industrial sectors in the world and one which poses many challenges for government regulators; inefficient regulation would have costly implications for the environment, human health, government budgets and the continued growth of this important global industry. Not only can different regulatory approaches and requirements in each OECD country create significant costs for the chemicals industry and for governments, they can also create barriers to trade.

If national approaches to chemical regulation are harmonised, industry is not faced with a plethora of conflicting or duplicative requirements, governments are provided with a common basis for working with each other, and non-tariff barriers to trade are reduced. The principal tools for harmonisation are a set of OECD Council Decisions which make up the OECD Mutual Acceptance of Data (MAD) system, including its OECD Guidelines for the Testing of Chemicals and OECD Principles of Good Laboratory Practice (GLP).