Proposition 65 is known as the Safe Water & Toxic Enforcement Act. It was enacted in 1986. The act requires anyone in the course of doing business who exposes an individual to a chemical “known to the State of California” to cause cancer or reproductive toxicity must first give a clear and reasonable warning. There are approximately 900 chemicals that have made the “Chemicals known to the state to cause cancer or reproductive toxicity” list (CCRTL). This list was compiled via various rodent studies and the trigger exposure amount is tiny.
Polypropylene plastic is not on the CCRTL list. Styrene is on the CCRTL and was added on April 22, 2016.