California Proposition 65

WARNING: Cancer and Reproductive Harm –


Proposition 65 FAQs

Why is there a warning on Lonseal’s products?

You may have seen the following warning associated with Lonseal products, as well as on other products purchased from other manufacturers:

“WARNING: This product contains one or more chemicals known to the State of California to cause cancer and birth defects or other reproductive harm.”

This warning is the result of a law passed in California in 1986 known as the California Safe Drinking Water and Toxic Enforcement Act of 1986, commonly referred to as “Proposition 65” or “Prop 65”.  Under Prop 65, California maintains a list of chemicals known to the state to cause cancer, birth defects, or other reproductive harm.  Any company whose product contains one or more of the roughly 900 Prop 65 listed chemicals must provide a notice to California consumers unless it can prove that any exposure is below a scientifically-established level.  Many of the items listed under Prop 65 have been routinely used in everyday consumer goods for years without documented harm.


Does this warning mean that Lonseal’s products are harmful?

This warning does not mean that Lonseal products will necessarily cause cancer or reproductive harm.  Furthermore, a Prop 65 warning does not mean a product is in violation of any federal or state product safety standards or requirements.  In fact, the California Attorney General has stated that Prop 65 is a “right to know law”, and a Prop 65 warning is not the same as a regulatory decision that a product is “safe” or “unsafe”.  See


When is a Prop 65 warning required?

A warning must be given if the listed chemical is merely present in a product unless a business demonstrates that the exposure it causes poses “no significant risk”.  With respect to carcinogens, the “no significant risk” level is defined as the level that is calculated to result in not more than one excess case of cancer in 100,000 individuals exposed over a 70-year lifetime.  With respect to reproductive toxicants, the “no significant risk” level is defined as the level of exposure which, even if multiplied by 1,000, will not produce birth defects or other reproductive harm.

It is cost prohibitive to test all chemicals in our products that are on the Prop 65 list and prove that the presence of a listed chemical is what California might consider a No Significant Risk Level (NSRL) or Maximum Allowable Dose Level (MADL).


Why is Lonseal providing this warning?

Lonseal has chosen to provide the Prop 65 warnings based on our knowledge about the presence of one or more listed chemicals in our products, without attempting to evaluate the level of exposure, as not all of the listed chemicals provide exposure limit requirements.  With Lonseal’s products, the exposure might be negligible or well within the “no significant risk” range.  However, out of an abundance of caution, Lonseal has chosen to provide the Prop 65 warnings.

The penalties for not complying with Prop 65 are high.  As a result of the potential penalties and because there is no penalty for providing an unnecessary warning, Lonseal, as well as many other manufacturers, has chosen to provide the warnings out of an abundance of caution in order to avoid the potential for liability.


I purchased this product outside of California; why is this warning included?

Lonseal’s products are sold nationwide.  It would be extremely difficult and costly to determine which products will be ultimately sold or brought into California.  Therefore, to ensure compliance with Prop 65 requirements, Lonseal has chosen to include the Prop 65 warnings on all Lonseal products, regardless of origin.


Where can I get more information about Proposition 65?

For more information about Proposition 65, please visit:


Are there other sources of information available?

The websites below all contain informative information you may find useful:

American Chemistry Council –

Center for Accountability in Science –

The Vinyl Institute –