The United Nations Conference on Environment and Development (Rio de Janeiro, June 1992) identifies 27 Principles in recognition of “the integral and interdependent nature of the Earth, our home.” Principle 15 defines the precautionary principle as:
“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.”
Environment Canada embraces this definition acknowledging, “The government’s actions to protect the environment and health are guided by the precautionary principle…”
A 2001 landmark decision by the Supreme Court of Canada cited the precautionary principle when it upheld the city of Hudson’s 1991 pesticide bylaws restricting the cosmetic use of pesticides. Justice Claire L’Heureux-Dubé:
“It is reasonable to conclude that the town bylaw’s purpose is to minimize the use of allegedly harmful pesticides in order to promote the health of its inhabitants…Permitting the town to regulate pesticide use is consistent with international law’s ‘precautionary principle,’ which states it is better to be overly cautious than to create a potential risk to the environment.”
Additionally, a conference held in 1998, The Wingspread Conference on the Precautionary Principle, gave its own definition of the practice as:
“When an activity raises threats of harm to human health or the environment, precautionary measures should be taken even if some cause and effect relationships are not fully established scientifically.”
(Convened by the Science and Environmental Health Network, the Johnson Foundation, the W. Alton Jones Foundation, the C.S. Fund and the Lowell Center for Sustainable Production at the University of Massachusetts-Lowell.)