MoCRA and California Prop 65 Are Separate Obligations

A maker gets facility registration and product listing sorted under MoCRA, feels the relief of having checked the federal box, then gets a Prop 65 warning letter six months later and can't figure out how both things can be true at once. Both things are true because they're answering different questions entirely.

What MoCRA actually requires

MoCRA, the Modernization of Cosmetics Regulation Act passed in 2022, is a federal framework. It requires facility registration and product listing with the FDA, a named responsible person, safety substantiation for your products, and adverse event recordkeeping. Some small businesses qualify for exemptions from the registration and listing pieces, though the exemption criteria are specific enough that it's worth confirming your business actually qualifies rather than assuming it.

MoCRA is about federal oversight of the cosmetic industry as a whole: who's making what, whether there's a real safety basis behind it, and whether adverse events get tracked and reported. It doesn't say anything about state-level consumer warning requirements, because that's not what it's for.

What Prop 65 actually requires

California's Prop 65 operates on a completely different premise. It requires a "clear and reasonable warning" before exposing Californians to chemicals the state has listed as known to cause cancer or reproductive harm, if your product contains those chemicals above the relevant level. It's not a product registration scheme at all. It's a warning obligation tied to specific listed chemicals potentially present in your product, triggered by selling into California regardless of where your business is based.

The chemical list Prop 65 covers, and the warning language and placement requirements, are maintained and enforced entirely separately from anything FDA-related. A product can be perfectly registered and listed under MoCRA, with a fully substantiated safety file, and still need a Prop 65 warning if it contains a listed chemical above the trigger level and it's sold to California consumers.

Why "I did the federal thing" doesn't cover you

The mistake is treating compliance as a single checklist where finishing the federal step means you're done. In practice, US cosmetic compliance is layered:

Requirement	Scope	What it checks
MoCRA	Federal, all US sales	Facility registration, product listing, safety substantiation, adverse event tracking
Prop 65	California only	Warning requirement for listed chemicals above trigger levels
State cosmetic rules (varies)	State-specific	Additional state requirements outside MoCRA and Prop 65

A brand selling nationwide needs to satisfy MoCRA everywhere, and separately needs to check every formula against the Prop 65 list if any product reaches California consumers, which for most online sellers, it will. These aren't alternative paths to the same compliance destination. They're both required, in parallel, for a huge share of US cosmetic sellers.

What this means for your ingredient list

The practical overlap point is your ingredients. The same ingredient list you're using for MoCRA safety substantiation is the list you need to check against the Prop 65 chemical list separately. This means:

• Keep an accurate, current ingredient list with real concentrations, not just trade names, since Prop 65 screening depends on knowing what's actually in the product at what level
• Recheck formulas against the Prop 65 list periodically, since California updates it and a formula that cleared last year isn't automatically clear indefinitely
• Don't assume an ingredient's absence from any federal restricted list means it's also absent from Prop 65's list. They're maintained by different bodies with different criteria

The practical fix

Treat MoCRA and Prop 65 as two separate compliance tracks that both need attention, not one task with two names. If you sell into California, which most US-facing ecommerce brands effectively do, budget the time to check your formulas against the Prop 65 list specifically, independent of whatever federal work you've already done.

Cosmetic Comply's US support is on the roadmap alongside the EU and Australia, with Canada live today. The ingredient mapping work underneath any of these systems, correct INCI names, CAS numbers, and real concentrations after accounting for supplier blends, is exactly the groundwork that makes checking against any list, federal or state, faster and less error-prone, which matters regardless of which specific US requirement you're squaring away first.