The precautionary principle is a pro-active measure to ensure that substances, processes and activities which are harmful to the environment are prevented from entering the environment. This is to ensure that costly subsequent restoration is avoided and that irreversible environmental degradation is avoided. Adverse effects include, but are not limited to: toxicity, bioaccumulation, bioconcentration, persistence, depletion of the stratospheric ozone layer, reduction of carbon sinks, increased greenhouse gases, increased human-induced climate change, reduction or loss of biodiversity, as well as heat, light and electro-magnetic radiation, atomic radiation, and hormone mimicry.
Every proponent of an intervention in the ecosystem must demonstrate that the intervention will not cause harm to the environment or will not create ecologically unsound wastes.
The proponent of an intervention shall demonstrate the safety of the intervention rather than the opponent having to demonstrate the harm of the intervention. This is also known as the "Reverse-onus principle." Proof of the non-hazardous or toxic nature of the product introduced into the environment will be on the proponent for any new type of product after a full life cycle analysis of all the potential environmental harm by non-vested interest parties.
Action to prevent, control or reduce the release of transport emissions harmful to health and the environment should not be postponed on the ground that scientific research has not fully proved a causal link between those emissions at which such action is aimed, on the one hand, and their potentially harmful impact on health and the environment, on the other.