Environmental Research Foundation  [Printer-friendly version]
January 21, 2008


By Peter Montague

The Wingspread Statement's definition of the precautionary principle
is now widely quoted:

"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.

"In this context the proponent of an activity, rather than the public,
should bear the burden of proof.

"The process of applying the Precautionary Principle must be open,
informed and democratic and must include potentially affected parties.
It must also involve an examination of the full range of alternatives,
including no action."

The Essence of Precaution:

Critics say that the precautionary principle is not well-defined.
However, the Science and Environmental Health Network (SEHN) points
out that, in all formulations of the precautionary principle, we find
three elements:

1) When we have a reasonable suspicion of harm, and

2) scientific uncertainty about cause and effect, then

3) we have a duty to take action to prevent harm.

The precautionary principle does not tell us what action to take.
However, proponents of a precautionary approach have suggested a
series of actions:

(1) Set goals;

(2) Examine all reasonable ways of achieving the goals, intending to
adopt the least-harmful way;

(3) Assume that all projects or activities will be harmful, and
therefore seek the least-harmful alternative. Shift the burden of
proof -- when consequences are uncertain, give the benefit of the
doubt to nature, public health and community well-being. Expect
responsible parties (not governments or the public) to bear the burden
of producing needed information. Expect reasonable assurances of
safety for products before they can be marketed -- just as the Food
and Drug Administration expects reasonable assurances of safety before
new pharmaceutical products can be marketed.

(4) Throughout the decision-making process, honor the knowledge of
those who will be affected by the decisions, and give them a real
"say" in the outcome. This approach naturally allows issues of ethics,
right-and-wrong, history, cultural appropriateness, and justice to
become important in the decision.

(5) Assume that humans will make mistakes and that decisions will
sometimes turn out badly. Therefore, monitor results, heed early
warnings, and be prepared to make mid-course corrections as needed;
this implies that we will avoid irreversible decisions and
irretrievable commitments.

Instead of asking the basic risk-assessment question -- "How much harm
is allowable?" -- the precautionary approach asks, "How little harm is

In sum: Faced with reasonable suspicion of harm, the precautionary
approach urges a full evaluation of available alternatives for the
purpose of preventing or minimizing harm.


Further reading:

In the U.S., the leading proponent of the precautionary approach is
the Science and Environmental Health Network (SEHN). Their web
site is a gold mine of information.

Here are some suggested readings:

Precautionary principle -- overviews

-- By Schettler, Barrett and Raffensperger (2002)
-- By Nancy Myers (2002)
-- The Wingspread Statement (1998)
-- By Jared Blumenfeld (2003)
-- Peter Montague, Opportunity of a Lifetime

Precautionary principle in the workplace:

-- By Eileen Senn (2003)

-- By Frank Ackerman and Rachel Massey (2002)

-- By The American Public Health Association (1996)

-- By Eileen Senn Tarlau (1990)

-- By Anne Stikjel and Lucas Reijnders (1995)

Precautionary principle and environmental justice:

-- By the California Environmental Protection Agency (2003)

-- By Peter Montague (Environmental Justice and Precaution, July, 2003)

-- By Peter Montague: Environmental Justice Requires the
Precautionary Principle (Feb., 2003)

Precautionary principle and municipal/county government:

-- The San Francisco Precaution Ordinance (2002)

-- The San Francisco White Paper on Precaution (2002)

Precautionary principle and environmental science:

-- By David Kriebel and others in Environmental Health Perspectives

Precautionary principle and children's health:

--By The American Public Health Association (2000)

Precautionary principle and public health:

-- By Tickner, Kriebel, and Wright (2003)

Precautionary Principle and Risk Assessment

Peter Montague, "Getting Beyond Risk Assessment"

Precaution and the Law

Joe Guth, Transforming American Law to Promote Preservation of the

Joe Guth, A model "little NEPA" law