CPGShield resources · California Proposition 65
California Proposition 65 is easy to oversimplify.
A chemical appears on the Proposition 65 list.
The ingredient appears in a formula.
Therefore the product needs a warning.
That logic is incomplete.
The better question is:
Does the product create an exposure to a listed chemical at a level that triggers the warning requirement?
California's Office of Environmental Health Hazard Assessment, or OEHHA, maintains the Proposition 65 list of chemicals known to the state to cause cancer, reproductive toxicity, or both.
Matching a product ingredient to the list is only the first screening step.
OEHHA explains that businesses can have “safe harbor” from warning requirements when exposure occurs at or below an applicable safe harbor level.
For carcinogens, these are generally No Significant Risk Levels.
For chemicals listed for reproductive toxicity, they are generally Maximum Allowable Dose Levels.
The key concept is exposure, not simple ingredient presence.
OEHHA states that when no safe harbor level has been established, a business that exposes individuals to a listed chemical generally must provide a warning unless it can demonstrate that the anticipated exposure does not trigger the warning requirement.
For cosmetics, that can involve:
That cannot be answered from a chemical name alone.
If presence alone does not decide the warning question, why screen against Proposition 65?
Because you cannot perform an exposure analysis for a chemical you never detected.
The screening layer identifies candidates for further evaluation.
This is especially important because chemical data may use:
CPGShield currently maintains more than 16,500 matchable Proposition 65 chemical names in its matching layer.
That number includes names and aliases used to improve detection. It should not be interpreted as that many unique chemicals on California's official list.
OEHHA maintains the official current list.
The larger matching count exists because real-world data does not always use one canonical name.
OEHHA discourages unnecessary warnings and advises businesses to consider qualified professional review when they believe an exposure may not require one.
The goal should be an accurate determination, not a blanket warning policy.
Screen formula or ingredient data against the current Proposition 65 list, including normalized aliases.
Confirm substance identity, source, concentration, and whether the listed chemical is actually present.
Evaluate the applicable safe harbor level or perform the appropriate exposure/risk analysis.
The final stage may require specialized professional judgment.
That is why CPGShield keeps Proposition 65 separate from federal ingredient prohibitions and state product restrictions.
Different rulebook. Different question. Different consequence.
Question for founders: if a Proposition 65 chemical match appeared in your formula tomorrow, would your system say “warning required”-or would it tell you what still needs to be determined?
A Proposition 65 match does not automatically mean “add a warning.” But missing a relevant chemical entirely is an even worse starting point.
CPGShield screens against more than 16,500 matchable Proposition 65 chemical names so you can identify potential matches early and understand what still requires exposure analysis or professional review.
Do not wait until a retailer, customer, or attorney raises the question after launch.
→ Screen your cosmetic product for Proposition 65 matches at CPGShield.com
Start free. Find the potential issue first-then decide what actually needs to be done.
This article is educational and does not determine whether any specific product requires a Proposition 65 warning.
Free cosmetic label compliance check. No demo required, no card. CPGShield LLC provides independent screening. We are not affiliated with, endorsed by, or acting for any retailer, brand, agency or organization we name.