Return to RMEHA Home page>

Rocky Mountain Environmental Health Association

Text of the San Francisco Precautionary Principle Policy:

Chapter 1 Precautionary Principle Policy Statement

Sec. 100. FINDINGS.

The Board of Supervisors finds and declares that:

A. Every San Franciscan has an equal right to a healthy and safe environment. This requires that our air, water, earth, and food be of a sufficiently high standard that individuals and communities can live healthy, fulfilling, and dignified lives. The duty to enhance, protect and preserve San Francisco's environment rests on the shoulders of government, residents, citizen groups and businesses alike.

B. Historically, environmentally harmful activities have only been stopped after they have manifested extreme environmental degradation or exposed people to harm. In the case of DDT, lead, and asbestos, for instance, regulatory action took place only after disaster had struck. The delay between first knowledge of harm and appropriate action to deal with it can be measured in human lives cut short.

C. San Francisco is a leader in making choices based on the least environmentally harmful alternatives, thereby challenging traditional assumptions about risk management. Numerous City ordinances including: the Integrated Pest Management Ordinance, the Resource Efficient Building Ordinance, the Healthy Air Ordinance, the Resource Conservation Ordinance, and the Environmentally Preferable Purchasing Ordinance apply a precautionary approach to specific City purchases and activities. Internationally, this model is called the Precautionary Principle.

D. As the City consolidates existing environmental laws into a single Environment Code, and builds a framework for new legislation, the City sees the Precautionary Principle approach as its policy framework to develop laws for a healthier and more just San Francisco. By doing so, the City will create and maintain a healthy, viable Bay Area environment for current and future generations, and will become a model of sustainability.

E. Science and technology are creating new solutions to prevent or mitigate environmental problems. However, science is also creating new compounds and chemicals that are already finding their way into mother's milk and causing other new problems. New legislation may be required to address these situations, and the Precautionary Principle is intended as a tool to help promote environmentally healthy alternatives while weeding out the negative and often unintended consequences of new technologies.

F. A central element of the precautionary approach is the careful assessment of available alternatives using the best available science. An alternatives assessment examines a broad range of options in order to present the public with different effects of different options considering short-term versus long-term effects or costs, and evaluating and comparing the adverse or potentially adverse effects of each option, noting options with fewer potential hazards. This process allows fundamental questions to be asked: "Is this potentially hazardous activity necessary?" "What less hazardous options are available?" and "How little damage is possible?"

G. The alternatives assessment is also a public process because, locally or internationally, the public bears the ecological and health consequences of environmental decisions. A government's course of action is necessarily enriched by broadly based public participation when a full range of alternatives is considered based on input from diverse individuals and groups. The public should be able to determine the range of alternatives examined and suggest specific reasonable alternatives, as well as their short- and long-term benefits and drawbacks.

H. This form of open decision-making is in line with San Francisco's historic Sunshine Act, which allows citizens to have full view of the legislative process. One of the goals of the Precautionary Principle is to include citizens as equal partners in decisions affecting their environment.

I. San Francisco looks forward to the time when the City's power is generated from renewable sources, when all our waste is recycled, when our vehicles produce only potable water as emissions, when the Bay is free from toxins, and the oceans are free from pollutants. The Precautionary Principle provides a means to help us attain these goals as we evaluate future laws and policies in such areas as transportation, construction, land use, planning, water, energy, health care, recreation, purchasing, and public expenditure.

J. Transforming our society to realize these goals and achieving a society living respectfully within the bounds of nature will take a behavioral as well as technological revolution. The Precautionary approach to decision-making will help San Francisco speed this process of change by moving beyond finding cures for environmental ills to preventing the ills before they can do harm.


The following shall constitute the City and County of San Francisco's Precautionary Principle policy. All officers, boards, commissions, and departments of the City and County shall implement the Precautionary Principle in conducting the City and County's affairs:

The Precautionary Principle requires a thorough exploration and a careful analysis of a wide range of alternatives. Using the best available science, the Precautionary Principle requires the selection of the alternative that presents the least potential threat to human health and the City's natural systems. Public participation and an open and transparent decision making process are critical to finding and selecting alternatives.

Where threats of serious or irreversible damage to people or nature exist, lack of full scientific certainty about cause and effect shall not be viewed as sufficient reason for the City to postpone measures to prevent the degradation of the environment or protect the health of its citizens. Any gaps in scientific data uncovered by the examination of alternatives will provide a guidepost for future research, but will not prevent protective action being taken by the City. As new scientific data become available, the City will review its decisions and make adjustments when warranted.

Where there are reasonable grounds for concern, the precautionary approach to decision-making is meant to help reduce harm by triggering a process to select the least potential threat. The essential elements of the Precautionary Principle approach to decision-making include:

1. Anticipatory Action: There is a duty to take anticipatory action to prevent harm. government, business, and community groups, as well as the general public, share this responsibility.

2. Right to Know: The community has a right to know complete and accurate information on potential human health and environmental impacts associated with the selection of products, services, operations or plans. The burden to supply this information lies with the proponent, not with the general public.

3. Alternatives Assessment: An obligation exists to examine a full range of alternatives and select the alternative with the least potential impact on human health and the environment including the alternative of doing nothing.

4. Full Cost Accounting: When evaluating potential alternatives, there is a duty to consider all the costs, including raw materials, manufacturing, transportation, use, cleanup, eventual disposal, and health costs even if such costs are not reflected in the initial price. Short- and long-term time thresholds should be considered when making decisions.

5. Participatory Decision Process: Decisions applying the Precautionary Principle must be transparent, participatory, and informed by the best available information.


No later than three years from the effective date of this ordinance, and after a public hearing, the Commission on the Environment shall submit a report to the Board of Supervisors on the effectiveness of the Precautionary Principle policy.


The Director of the Department of the Environment shall produce and maintain a list of all City and County of San Francisco ordinances and resolutions which affect or relate to the environment and shall post this list on the Department of the Environment's website.


The Board of Supervisors encourages all City employees and officials to take the precautionary principle into consideration and evaluate alternatives when taking actions that could impact health and the environment, especially where those actions could pose threats of serious harm or irreversible damage. This ordinance does not impose specific duties upon any City employee or official to take specific actions. In adopting and undertaking the enforcement of this ordinance, the City and County of San Francisco is assuming an undertaking only to promote the general welfare. It is not assuming, nor is it imposing on its officers and employees, an obligation for breach of which it is liable in money damages to any person who claims that such breach proximately caused injury nor may this ordinance provide any basis for any other judicial relief including, but not limited to a writ of mandamus or an injunction.



[2] See

[3] See

[4] "White Paper - The Precautionary Principle and the City and County of San Francisco" (March, 2003). See

Allison A. Brown
Dept. of Disability and Human Development
College of Applied Health Sciences
University of Illinois at Chicago
1640 W. Roosevelt Rd.
Chicago, Illinois 60608
312.413.1588 (V) 312.413.0453 (TTY)

Follow the links below to learn more about RMEHA and Environmental Illness.

Revised '21-Dec-2009,11:59:26'