Frequently Asked Questions


Proposition 65 is the Safe Drinking Water and Toxic Enforcement Act passed by voters in the State of California in 1986. The act was created to inform people about possible exposure to chemicals known by the State of California to cause cancer, birth defects and/or other reproductive harm.

Proposition 65 requires that the Governor of California maintain and publish a list of harmful chemicals. The list is updated annually and includes chemicals that can be found in solvents, drugs, dyes, food additives, by-products of certain processes, pesticides, and tobacco products.

A chemical is listed if it has been classified as a reproductive toxicant or carcinogen by an "authoritative" organization on the subject. The U.S. Environmental Protection Agency, U.S. Food and Drug Administration, National Institute for Occupational Safety and Health, the National Toxicology Program, and the International Agency for Research on Cancer are considered authoritative for carcinogens. For reproductive toxicants, the authorities are the U.S. Environmental Protection Agency, U.S. Food and Drug Administration, National Institute for Occupational Safety and Health, and International Agency for Research on Cancer. Chemicals will also be listed if they are required to be labeled or identified as a carcinogen or as a reproductive toxicant by an agency of the state or federal government.

Any company with ten or more employees operating or selling products within the State of California must comply with the requirements of Proposition 65. To comply, businesses are: (1) prohibited from knowingly discharging listed chemicals into sources of drinking water; and (2) required to provide a "clear and reasonable" warning before knowingly and intentionally exposing anyone to a listed chemical.


A Proposition 65 warning means that the business has evaluated the exposure and has concluded that it exceeds the "no significant risk level,” or that the business is providing a warning based on the presence of a “listed” chemical without actually evaluating the exposure.


Therm-a-Rest is providing a warning based on our knowledge about the presence of one or more listed chemicals without attempting to evaluate the level of exposure. While using a Therm-a-Rest product, the exposure to a “listed” chemical may be well within the “no significant risk” range, but out of caution, we have placed the Proposition 65 warning labels on our products.

The California government states: “The fact that a product bears a Proposition 65 warning does not mean by itself that the product is unsafe.” The government also explained, “You could think of Proposition 65 more as a ‘right to know’ law than a pure product safety law.”

A Proposition 65 warning means that the product contains one or more listed chemicals. By law, a warning is required unless the business proves that the exposure to the chemical poses "no significant risk." The "no significant risk" level for carcinogens is defined as the level which is calculated to result in not more than one excess case of cancer in 100,000 individuals exposed over a 70-year lifetime. Therefore, if you are exposed to the chemical in question at this level every day for 70 years, theoretically, it will increase your chances of getting cancer by no more than 1 case in 100,000 individuals so exposed.

The "no significant risk" level for reproductive toxicants is defined as the level of exposure which, even if multiplied by 1,000, will not produce birth defects or other reproductive harm. Therefore, the level of exposure is below the "no observable effect level," divided by 1,000. (The "no observable effect level" is the highest dose level which has not been associated with observable reproductive harm in humans or test animals.)

For further information about California’s Proposition 65, please visit http://oehha.ca.gov/prop65/background/p65plain.html