(Published Dec. 4, 2003)
This week our good friend Mary O'Brien describes common
criticisms of the precautionary principle, and examines San
Francisco's precautionary ordinance to see if these criticisms
are valid. Mary is especially well qualified to do this because
San Francisco officials relied on Mary's book, Making Better
Environmental Decisions, in writing their ordinance. As you
all know by now, the precautionary principle is the "better
safe than sorry" approach to decisions.
This past summer, when the City and County of San Francisco,
California adopted the precautionary principle to guide all
public policies that affect the environment, it caused panic
inside the chemical industry.
For 100 years the chemical industry has been exposing workers
and communities to toxic chemicals without anyone's informed
consent, an ethical lapse (and source of legal liability) of
titanic proportions. Now the precautionary approach is
suggesting that chemicals should be tested before people are
exposed. Who knows where such crazy ideas might lead?
In late November, the Environmental Working Group (
published a secret memo, written by the American Chemistry
Council (ACC, formerly known as the Chemical Manufacturers
The leaked memo outlines a secret ACC campaign to be led by an
"attack dog" PR firm, Nichols-Dezenhall, to "stigmatize" the
precautionary principle (PP) and "win control of the message
war" in California. The memo says that the precautionary
principle (PP) is a "top priority" for the American Chemistry
Council because the PP is too common-sense: "For too long, the
'common sense' appeal of the PP has gone unopposed," the memo
says. "Moreover, California is a bellwether state, and any
success enjoyed here could readily spill over to other parts of
the country," the memo says. Common sense spilling over! This
Please read this hilarious (and chilling) memo for yourself,
and the press coverage it received in California.[4,5] And now
here's Mary O'Brien's examination of industry's critique of the
precautionary principle. --Peter Montague
Critiques of the Precautionary Principle
by Mary O'Brien*
Five critiques of the Precautionary Principle are particularly
1. The Precautionary Principle is vague and therefore useless.
2. It is about values and emotion, not science.
3. If implemented, it would strangle technological and economic
4. It arises out of a naive wish for a risk-free world.
5. It ignores risk assessment, thereby leading to the dangerous
possibility that an alternative that is adopted may cause far
more harm than the original proposed activity.
In contrast to these critiques, San Francisco's (SF's) July
2003 precautionary principle ordinance, provides a classic
example of just how reasonable, practical, and wise the
implementation of precaution can be, and how baseless are the
critiques of the principle.
Critique #1: The Precautionary Principle is vague.
Response: San Francisco's (SF's) ordinance clearly describes
specifics of the Precautionary Principle.
Any statement of any precautionary approach is vague to begin
with, just as the Hippocratic Oath taken by all physicians, "Do
No Harm," is vague. But when a community, state, nation or
treaty articulates and implements a precautionary approach in a
specific situation, it is not vague. San Francisco's ordinance,
for instance, makes clear who, what, when, where, how, and why:
WHY: General Welfare
The first finding declared by the SF Board of Supervisors in
its precautionary principle ordinance is that every San
Franciscan has an equal right to air, water, earth, and food
that is of a sufficiently high quality "...that individuals and
communities can live healthy, fulfilling, and dignified lives"
This isn't science. This is a value. And yet each word,
"healthy," "fulfilling," and "dignified" has meaning that most
citizens would broadly agree upon.
WHO: Government, Residents, Citizen Groups, Businesses
San Francisco's ordinance explicitly requires "all officers,
boards, commissions, and departments of the City and County" to
implement the Precautionary Principle in conducting city
affairs. It also states that business, community groups, and
the general public share the responsibility to take
"anticipatory action to prevent harm."
WHAT: City Ordinances, Decisions
The ordinance requires that the precautionary approach be
applied not only to ordinances and resolutions, but also to
ordinary conduct of City affairs.
HOW: Public Process
San Francisco's ordinance makes clear that its precautionary
approach is an aggressively public process, including
transparent decisionmaking, public right to know about
environmental and economic impacts of options, and public
participation in determining the range of alternatives to be
The ordinance's "how" also includes a value-based guide to
selecting among those alternatives: ask whether a given
hazardous activity is necessary, and if it isn't, select the
alternative with the least potential impact on human health and
the environment. "Inherent in the Precautionary Principle
policy," the findings observe, "is a belief that a risk that is
unnecessary, and not freely chosen, is not acceptable."
Thus, wise alternatives must not only be considered, they must
WHERE: All Decisions Affecting the Environment
The ordinance specifically mentions applying the precautionary
principle to "...such areas as transportation, construction,
land use, planning, water, energy, health care, recreation,
purchasing, and public expenditure." This is both ambitious and
a large challenge.
WHEN: Past, Present, and Future
The findings in the ordinance note that through San Francisco's
Sunshine Act and various environmental ordinances such as their
Integrated Pest Management Ordinance and Resource Efficient
Building Ordinance, precaution is not new to San Francisco.
Thus, the precautionary principle ordinance is an expansion of,
not a departure from, past approaches.
Within three years of the passage of the ordinance, the
Environment Commission must submit a report on the
effectiveness of the policy.
Critique #2: The Precautionary Principle is about values, not
Response: The San Francisco Precautionary Principle is about
values and science.
The oft-heard critique that the precautionary principle
abandons science to simply put forward a value of zero risk is
rendered moot by San Francisco's simple statement that
application of the Precautionary Principle will involve
"careful assessment of available alternatives using the best
available science." All reasonably foreseeable costs should be
considered, "even if such costs are not reflected in the
initial price." Moreover, "As new scientific data become
available, the City will review its decisions and make
adjustments when warranted."
Critique #3: The Precautionary Principle stifles progress.
Response: San Francisco's Precautionary Principle encourages
both technological progress and behavioral progress.
The ordinance notes, "Science and technology are creating new
solutions to prevent or mitigate environmental problems." In
other words, science and technology need not create only
environmentally hazardous technologies; they are also creating,
and are capable of creating, solutions to prevent or mitigate
environmental problems. Thus, the precautionary principle is an
effective facilitator of technological progress.
But the San Francisco ordinance also expands the meaning of
progress beyond the horizons of technology. "Achieving a
society living respectfully within the bounds of nature," the
ordinance notes, "will take a behavioral revolution." Easier
said than done, of course, because we are all creatures of
habit, and some businesses and individuals defend
business-as-usual, even when that business-as-usual or
shopping-as-usual ignores the bounds of nature or is killing
our children. Thus the city's conscious use of the term
Critique #4: The Precautionary Principle requires a risk-free
Response: The San Francisco Precautionary Principle requires
less harm, not zero harm.
Wisely, the San Francisco ordinance does not require those
defending a potentially hazardous activity to prove it is safe.
Essentially nothing we do is "safe." Our daily use of
electricity is not "safe" for salmon that are blocked by
hydroelectric dams. Our daily discharge of our own personal
wastes into clean water is not "safe" for native aquatic
Instead, the San Francisco ordinance aims to reduce impacts on
the environment, which means more health. Prior to selecting an
alternative, there is "a duty to consider all the reasonably
foreseeable costs [of alternatives]." Analysis of reasonably
foreseeable environmental, health, and economic costs of any
alternative usually reveals some potential for harm. Following
analysis, decision makers are directed to "select the
alternative with the least potential impact on human health and
the environment." Thus, the San Francisco ordinance states no
expectation that all harm, all impact, all risk of harm will be
absent from the alternatives chosen.
Critique #5: The Precautionary Principle throws out risk
assessment; alternatives might cause more harm.
Response: The San Francisco Precautionary Principle assesses
risks and benefits of alternatives.
San Francisco figures the Precautionary Principle requires "a
thorough exploration and a careful analysis of a wide range of
alternatives." It cautions against focusing only on short-term
or immediate impacts: "Short and long-term benefits and time
thresholds should be considered." What the ordinance avoids
through consideration of alternatives is the widespread "risk
assessment" practice of accepting a hazardous activity as a
beginning and end, and then analyzing how much of the activity
or technology is safe, or of insignificant risk or at least
acceptable. The acceptability or unacceptability of a given
activity or technology, will usually vary significantly
depending on the consideration or lack of consideration of
alternatives. Polyvinyl chloride (PVC), for instance, long
seemed a great building material: long-lasting, versatile, low
maintenance. When looking at its toxic manufacturing process,
difficulty of disposal, firefighting hazards, and availability
of alternatives, however, using vinyl as a construction
material rapidly loses its acceptability.
ESSENTIAL ELEMENTS OF A PRECAUTIONARY POLICY
San Francisco's approach to the Precautionary Principle is not
the only reasonable or necessarily the best approach. But four
elements seem essential in any significant precautionary
approach (regardless of whether it is called that or not), and
all four are present in San Francisco's ordinance:
1. Commitment to giving health the benefit of the doubt when
harm is uncertain, but appears plausible.
2. Enabling fully informed public participation, particularly
in the process of
3. Formulating a full range of reasonable alternatives, and
4. Transparently using technical and scientific information to
analyze the alternatives.
It is important for government officials to acknowledge they
are often not well-trained or even well-versed in a full range
of alternatives that are relevant to a particular planning
process, or a particular public health goal, or any other
decisions that must be made.
Participation by the public, vendors, and businesses can
greatly enrich the field of options for analysis. As a
scientist who has worked for most of the past 22 years for
nongovernmental organizations which have articulated and
developed alternatives in many planning efforts, I cannot
emphasize enough the wisdom of including citizens as (to once
again quote San Francisco's ordinance) "...equal partners in
decisions affecting their environment."
When we choose among alternatives, we don't want to jump from
the frying pan into the fire. We need information to inform our
decision making. Even the absence of sufficient information is
information: It says we still know too little about what we are
doing to the environment and, thus, to each other. And if we
care about each other and our fellow creatures, acknowledgement
of our ignorance should lead us full circle back to the
essential value of siding with environmental health when
decisions must be made amid missing information.
Have San Franciscans begun to implement their brand new
precautionary principle ordinance? Yes, but so far mostly in
the arena of toxics. Debbie Raphael, Toxics Reduction Program
Manager in the city's Department of Environment, has been
helping organize public meetings to guide the drafting of an
environmentally sound purchasing ordinance.
"The City's intent has long been to minimize harm," Raphael
observes, "but with the precautionary principle ordinance,
we're now adding major public involvement throughout the
process. We're paying attention to how we craft and implement
policy, not simply whether City staff thinks it is sufficiently
"Who knows how much things will change once the public becomes
engaged fully in determining alternatives for transportation,
construction, land use, water, energy, health care, recreation,
and public expenditures?" Raphael asks.
Probably a lot.
* Mary O'Brien, Ph.D., former staff scientist with
Environmental Research Foundation, is the author of Making
Better Environmental Decisions: An Alternative to Risk
Assessment (Cambridge, Mass.: MIT Press, 2000). She is
currently working on alternatives for three Utah national
 Mary O'Brien, Making Better Environmental Decisions: An
Alternative to Risk Assessment (Cambridge, Mass: MIT Press,
 American Chemistry Council, "Nichols-Dezenhall
Precautionary Principle Campaign Proposal" (undated, but leaked
Nov. 21, 2003). See