Precautionary Principle
What does "Precautionary Principle" mean in law?
The precautionary principle holds that where an activity raises threats of serious or irreversible environmental harm, scientific uncertainty about the precise nature or magnitude of the harm should not be used as a reason to postpone cost-effective measures to prevent environmental degradation. Articulated in Principle 15 of the 1992 Rio Declaration, the principle shifts the burden of proof from those seeking to protect the environment to those proposing potentially harmful activities, requiring proponents to demonstrate safety rather than opponents to prove danger. While European Union environmental law explicitly incorporates the precautionary principle as a legal standard, U.S. environmental law applies it more implicitly through provisions like the Clean Air Act's requirement that NAAQS protect public health with an "adequate margin of safety" and FIFRA's precautionary approach to pesticide registration. The principle remains controversial in U.S. regulatory policy, with critics arguing it can stifle innovation and supporters contending it is essential for preventing catastrophic and irreversible environmental damage.
Definition
The precautionary principle holds that where an activity raises threats of serious or irreversible environmental harm, scientific uncertainty about the precise nature or magnitude of the harm should not be used as a reason to postpone cost-effective measures to prevent environmental degradation. Articulated in Principle 15 of the 1992 Rio Declaration, the principle shifts the burden of proof from those seeking to protect the environment to those proposing potentially harmful activities, requiring proponents to demonstrate safety rather than opponents to prove danger. While European Union environmental law explicitly incorporates the precautionary principle as a legal standard, U.S. environmental law applies it more implicitly through provisions like the Clean Air Act's requirement that NAAQS protect public health with an "adequate margin of safety" and FIFRA's precautionary approach to pesticide registration. The principle remains controversial in U.S. regulatory policy, with critics arguing it can stifle innovation and supporters contending it is essential for preventing catastrophic and irreversible environmental damage.
Example
Invoking the precautionary principle, a coastal state banned a new class of industrial pesticides pending further study after preliminary evidence suggested the chemicals might cause irreversible harm to marine ecosystems, even though definitive proof of harm had not yet been established.