The concept of sustainable development calls for the application of many principles – including public participation, polluter pays, intergenerational equity, community-based management, indigenous rights and environmental impact assessment. Fundamental in combating land-based pollution is the precautionary principle, also known as the precautionary ‘approach’. It urges a shift away from the traditional belief in the assimilative capacity of the oceans to absorb wastes and faith in end-of-pipe standards to achieve acceptable environmental quality standards. The precautionary principle is torn between competing philosophies towards nature and natural resources. In its strictest form, it calls for quite extreme law and policy reforms that emphasise pollution prevention and the need to develop clean technologies and products.

Extreme control measures may include the establishment of zero discharge (or virtual elimination) standards for synthetic chemicals, a ‘reverse listing’ approach to chemicals management where only ‘safe’ chemicals are listed for use, and a shift in the burden of proof to those proposing development activities to show some standard of safety. Best available technology without regard to costs is a further direct measure often advocated.

A more utilitarian view of precaution, as articulated in Principle 15 of the Rio Declaration on Environment and Development, supports an array of less extreme management measures. Reliance on cost–benefit and risk–benefit assessments is viewed as critical in reaching rational decisions. Flexible trade-offs between environmental and economic values are encouraged through application of best available techniques (with consideration given to costs).