A precautionary approach to addressing environmental threats can be traced back to domestic German law in the 1970s.  The principle was first used in an international agreement in 1980.  However, it was at the 1992 United Nations Conference on Environment and Development that it first received broad international recognition in the Rio Declaration on Environment and Development of 1992. offsite link The Declaration states in Principle 15 that “[i]n order to protect the environment, the precautionary approach shall be widely applied by States according to their capabilities.  Where there are threats of serious or irreversible damage, lack of full scientific certainty shall not be used as a reason for postponing cost-effective measures to prevent environmental degradation.”  Principle 15, Rio Declaration. 

The precautionary approach has since been incorporated into several treaties, international agreements, and other instruments to which the United States is a signatory or a party, including:

• 1980 Convention on the Conservation of Antarctic Marine Living Resources offsite link. “A ‘precautionary’ approach has been implemented to minimise risk associated with unsustainable practices in conditions of uncertainty." General Introduction. offsite link (U.S. signed on 9/11/1980; Senate gave its advice and consent on 12/16/1981; U.S. ratified on 2/18/1982).
• 1987 Montreal Protocol on Substances that Deplete the Ozone Layer. offsite link “Noting the precautionary measures or controlling emissions of certain chlorofluorocarbons that have already been taken at national and regional levels.” Preamble. (U.S. signed offsite link on 9/16/1987; Senate voted to approve ratification on 3/15/1988; President signed the instrument of ratification on 4/5/1988; U.S. ratified offsite link on 4/21/1988).
• 1992 Convention on Biological Diversity offsite link.  “…where there is a threat of significant reduction or loss of biological diversity, lack of full scientific certainty should not be used as a reason for postponing measures to avoid or minimize such a threat,” Preamble. (U.S. signed offsite link 6/4/1993; Senate has yet to give its advice and consent).

• 1992 United Nations Framework Convention on Climate Change offsite link. “The Parties should take precautionary measures to anticipate, prevent or minimize the causes of climate change and mitigate its adverse effects.”  Article 3(3). (U.S. signed offsite link on 6/12/1992; Senate gave its advice and consent on 10/7/1992; U.S. ratified offsite link on 10/15/1992).
• 1995 WTO Agreement on the Application of Sanitary and Phytosanitary Measures offsite link. “In cases where relevant scientific evidence is insufficient, a Member may provisionally adopt sanitary or phytosanitary measures on the basis of available pertinent information.” Article 5(7). (U.S. signed 4/15/1994 and approved through Congressional action on 12/8/1994: Uruguay Round Agreements Act, Public Law 103-465).
• 1995 United Nations Fish Stocks Agreement. offsite link “States shall apply the precautionary approach widely to conservation, management and exploitation of straddling fish stocks and highly migratory fish stocks in order to protect the living marine resources and preserve the marine environment.”  Article 6(1). (U.S. signed offsite link on 12/4/1995; Senate gave its advice and consent on 6/27/1996; U.S. ratified offsite link on 8/21/1996).
• 1995 UN Food and Agriculture Organization Code of Conduct for Responsible Fisheries offsite link. “States and subregional and regional fisheries management organizations should apply a precautionary approach widely to conservation, management and exploitation of living aquatic resources in order to protect them and preserve the aquatic environment, taking account of the best scientific evidence available.”  Articles 6.5, 7.5.1. (NOAA published an updated implementation plan for the FAO Code of Conduct for Responsible Fisheries in 2012, documenting the U.S. commitment to implementing the Code of Conduct both domestically and internationally).
• 1996 Protocol to the 1972 London Convention on the Dumping of Wastes and Other Matter. “In implementing this Protocol, Contracting Parties shall apply a precautionary approach to environmental protection from dumping of wastes…” Article 3(1). (U.S. signed in 1998; Senate has yet to give its advice and consent).
• 1997 Protocol to the International Convention for the Prevention of Pollution From Ships. (“1997 MARPOL Protocol”) “…Recognizing Principle 15 of the Rio Declaration on Environment and Development which calls for the application of a precautionary approach.” Preamble. (U.S. signed on 12/22/1998; Senate gave its advice and consent on 4/7/2006; U.S. ratified on 1/8/2009).
• 1998 Agreement on the International Dolphin Conservation Program. offsite link “The Parties shall…apply the precautionary approach, consistent with the relevant provisions of the FAO Code of Conduct for Responsible Fisheries and the United Nations Agreement on Straddling Fish Stocks and Highly Migratory Fish Stocks.”  Article IV(1).  (U.S. signed offsite link on 5/21/1998; and approved through Congressional action 08/15/1999: International Dolphin Conservation Program Act, 16 U.S.C 1411; U.S. ratified offsite link on 7/21/1998).
• 1998 North Atlantic Salmon Conservation Organization (NASCO) Agreement on Adoption of a Precautionary Approach. offsite link The contracting parties to NASCO agreed to “adopt and apply a Precautionary Approach to the conservation, management and exploitation of salmon in order to protect the resource and preserve the environments in which it lives.”  CNL(98)46 offsite link Paragraph 1.  (U.S. is a party offsite link to NASCO, having ratified offsite link the Convention for the Conservation of Salmon in the North Atlantic Ocean, which established NASCO, on 11/16/1982).
• Protocols to the 1979 Convention on Long-Range Transboundary Air Pollution offsite link (LRTAP):
  • 1998 LRTAP Persistent Organic Pollutants Protocol offsite link. “Resolved to take measures to anticipate, prevent or minimize emissions of persistent organic pollutants, taking into account the application of the precautionary approach, as set forth in Principle 15 of the Rio Declaration on Environment and Development.”  Preamble. (U.S. signed offsite link on 6/24/1998; Senate has yet to give its advice and consent).
  • 1998 LRTAP Heavy Metals Protocol. offsite link “Resolved to take measures to anticipate, prevent or minimize emissions of certain heavy metals and their related compounds, taking into account the application of the precautionary approach, as set forth in principle 15 of the Rio Declaration on Environment and Development,” Preamble.  (U.S. signed offsite link the Protocol on 6/24/1998 and accepted offsite link it on 1/10/2001).
  • 1999 LRTAP Acidification Protocol. offsite link “Resolved to take measures to anticipate, prevent or minimize emissions of these substances, taking into account the application of the precautionary approach as set forth in Principle 15 of the Rio Declaration on Environment and Development."  Preamble.  (U.S. signed offsite link on 12/1/1999, and accepted offsite link it on 11/22/2004).
• 2000 Convention on the Conservation and Management of Highly Migratory Fish Stocks in the Western and Central Pacific Ocean. offsite link “In order to conserve and manage highly migratory fish stocks, the members of the Commissions shall ... apply the precautionary approach in accordance with this Convention and all relevant internationally agreed standards and recommended practices and procedures.”  Article 5(c). “In applying the precautionary approach, the members of the Commission shall: (a) apply the guidelines set out in Annex II of the Agreement, which shall form an integral part of this Convention, and determine, on the basis of the best scientific information available, stock specific reference points and the action to be taken if they are exceeded; etc.”  Article 6(a). (U.S. signed on 9/5/2000; Senate gave its advice and consent on 11/18/2005; U.S. ratified on 5/15/2007).
• 2001 International Convention on the Control of Harmful Anti-Fouling Systems on Ships. “Mindful of the precautionary approach set out in Principle 15 of the Rio Declaration on Environment and Development…”  Preamble.  (U.S. signed 12/12/2002; Senate gave its advice and consent on 9/ 26/2008; U.S. ratified offsite link on 8/21/2012).
• 2001 Agreement on the Conservation of Albatrosses and Petrels. offsite link “Recognising the Rio Declaration on Environment and Development, 1992, Principle 15, that, in order to protect the environment, the precautionary approach should be widely applied;” Preamble. Submitted to the Senate for advice and consent on 9/26/2008, but the Senate has yet to act).
• 2001 Stockholm Convention on Persistent Organic Pollutants. offsite link “Mindful of the precautionary approach as set forth in Principle 15 of the Rio Declaration on Environment and Development, the objective of this Convention is to protect human health and the environment from persistent organic pollutants.”  Article 1. (U.S. signed offsite link on 5/23/2001; President submitted the treaty to the Senate for advice and consent on 4/6/2002; Senate has not yet given its advice and consent).
• 2018 Agreement to Prevent Unregulated High Seas Fisheries in the Central Arctic Ocean. offsite link “Desiring, consistent with the precautionary approach, to prevent the start of unregulated fishing in the high seas portion of the central Arctic Ocean while keeping under regular review the need for additional conservation and management measures.”  Preamble. “The objective of this Agreement is to prevent unregulated fishing in the high seas portion of the central Arctic Ocean through the application of precautionary conservation and management measures.”  Article 2. “During their meetings, the Parties shall…taking into account…the precautionary approach…consider, inter alia, whether the distribution, migration and abundance of fish in the Agreement Area would support a sustainable commercial fishery.”  Article 5(1)(c).  (U.S. signed on 10/3/2018, following a Congressional joint resolution calling for such a resolution issued on 6/3/2008; The Agreement entered into force on 6/5/2021).  A media note issued by the State Department on June 25, 2021, to highlight the Agreement described it as "the first multilateral agreement of its kind to take a legally binding, precautionary approach to protect an area from commercial fishing before such fishing has begun."
• 2023 Agreement under the United Nations Convention on the Law of the Sea on the Conservation and Sustainable Use of Marine Biological Diversity of Areas beyond National Jurisdiction offsite link. "In order to achieve the objectives of this Agreement, Parties shall be guided by the following principles and approaches: * * * The precautionary principle or precautionary approach, as appropriate." Article 7(e). "Proposals [regarding the establishment of area-based management tools] shall be formulated on the basis of the best available science and scientific information and, where available, relevant traditional knowledge of Indigenous Peoples and local communities, taking into account the precautionary approach and an ecosystem approach."  Article 19(e). (U.S. signed on 9/20/23).  The 2016 Digest of US Practice in International Law at p. 563, states: "The United States strongly supports the protection of the marine environment, both within and beyond national jurisdiction, and believes the conservation aspects we are discussing in this Prepcom are critical elements of any potential instrument. We are committed to an ecosystem-based approach to the management of the ocean, using the precautionary approach, and the best available science. This includes using tools such as marine protected areas and coastal and marine planning, which consider all uses of the environment towards the goal of conservation and sustainable use."

Additional reference information:

• The United Nations Food and Agriculture Organization (FAO) webpage on the “Precautionary Approach to Fisheries Management” offsite link
• International Maritime Organization (IMO), Guidelines on Incorporation of the Precautionary Approach in the Context of Specific IMO Activities offsite link (Sept. 1995)
• UNESCO, World Commission on the Ethics of Scientific Knowledge and Technology (COMEST), The Precautionary Principle offsite link (2005)
• The 1982 World Charter for Nature offsite link(stating that "activities which are likely to pose a significant risk to nature shall be preceded by an exhaustive examination; their proponents shall demonstrate that expected benefits outweigh potential damages to nature, and where potential adverse effects are not fully understood, the activities shall not proceed." G.A. Res. 37/7, U.N. GAOR, 37th Sess., Supp. No. 51, at 21, U.N. Doc. A/37/L.4 and Add. I (1982).

(Last updated July 25, 2024)