Proposition 65 Fact Sheet for Tenants

This fact sheet was prepared by the Office of Environmental Health Hazard Assessment (OEHHA), which administers the Proposition 65 program. It provides information to tenants whose apartment managers and owners have posted or distributed Proposition 65 warnings.

What is Proposition 65?

In 1986, California voters approved an initiative to address their growing concerns about exposure to toxic chemicals. That initiative became the Safe Drinking Water and Toxic Enforcement Act of 1986, better known by its original name of Proposition 65. Proposition 65 requires the State to publish a list of chemicals known to cause cancer, birth defects, or other reproductive harm. The list has grown to include over 800 chemicals since it was first published in 1987. 

What chemicals are on the Proposition 65 list?

The Proposition 65 list contains two types of chemicals: carcinogens, which can cause cancer, and reproductive toxicants, which cause birth defects or other reproductive harm, such as sterility or miscarriages. Some chemicals may be additives or ingredients in pesticides, common household products, food, or drugs. Others may be industrial chemicals, dyes, or solvents used in dry cleaning, manufacturing, and construction. Still others may be byproducts of chemical processes; for example, motor vehicle exhaust.

What does a Proposition 65 warning mean?

Under Proposition 65, businesses are required to give a “clear and reasonable” warning before knowingly exposing anyone to a listed chemical above a specified level. This warning can be included on the label of a consumer product or published in a newspaper. An equally common practice is for businesses to provide a warning at the workplace or in a public area affected by the chemical.

Many apartment owners and managers have posted or distributed warnings to notify tenants that they may be exposed to one or more chemicals on the Proposition 65 list. For example, a warning may be given because tenants are exposed to chemicals in pesticides applied to landscaping or structures or chemicals in housing construction materials, such as lead in paint or asbestos in ceiling coatings. 

A growing trend among rental property owners and other businesses is to provide warnings for chemicals on the list, such as tobacco smoke or motor vehicle exhaust, which are regularly released into the environment in or near rental housing. In some cases, however, owners and managers are providing warnings to avoid potential violations and lawsuits, even though exposure to chemicals on the Proposition 65 list has not been verified. You should discuss the warning with the owner or manager to learn why it was provided so that you and your family can make informed decisions about exposure to any of these chemicals and your health.

Is my family’s health at risk from exposure to these chemicals?

Warnings must be provided for chemicals listed under Proposition 65 if exposure to them may present a significant risk of cancer or reproductive harm. For carcinogens, the chemical must be present at or above a level that could cause one additional case of cancer in a population of 100,000 people exposed to the chemical over a lifetime. For reproductive toxicants, the chemical must be present at or above 1/1000th of the level at which the chemical is determined to have no negative health risks (the “no-observable-effect level”).

Proposition 65 generally does not prohibit a business from exposing people to listed chemicals nor does exposure to these chemicals necessarily create an immediate health risk. Also, as stated above, a warning may have been provided in some cases even though the level at which the chemical is present is actually too low to pose a significant health risk. It is important to find out why you have received the warning so that you can discover which chemicals you are exposed to, and at what levels, to determine how best to protect your family’s health.

Where can I get more information?

Speak with the housing owner or manager directly to learn why you received a Proposition 65 warning. Property owners and managers are not required to notify OEHHA when they provide tenants with a warning. However, to obtain general information on the Proposition 65 list of chemicals, you may contact OEHHA at (916) 445-6900. Following is a list of contacts for more information on Proposition 65 as well as chemicals that may be found in your home.

Type of Information


Proposition 65: Enforcement

California Attorney General 
(510) 873-6321,

Indoor air quality

Indoor Exposure Assessment Unit, Air Resources Board
(916) 322-8282,


Tenant issues

Basis for Warning Signs