The warning in your Use and Care Guide is printed in order for Whirlpool Corporation to comply with California State law and is based on the list of chemicals identified by the Governor of the State of California as provided in Proposition 65 regulations.
California Proposition 65 is known as The Safe Drinking Water and Toxic Enforcement Act of 1986. To comply with this California Act, even chemicals used within the limits of national regulations and found not hazardous in the quantities associated with the product may require a warning just because the chemical is present. Information about Proposition 65 and this warning is available on the website of the Office of Environmental Health Hazard Assessment (OEHHA) maintained by the State of California. http://www.oehha.org/prop65.html
Whirlpool evaluates all chemicals associated with the products that Whirlpool manufactures and complies with all regulations associated with the chemicals. All potential chemical exposures are below accepted and regulated concentrations. Whirlpool has provided the warning because a chemical covered by the California Proposition 65 may be present and not all listed chemicals provide exposure limit requirements. Therefore, Whirlpool has elected to provide the warning when a listed chemical is present.