California PRC §42357 (AB 1201) Explained: Degradable and Compostable Claims on Packaging Labels

What PRC §42357 actually does

California Public Resources Code §42357, as amended by AB 1201 (2021-22), "Solid waste: products: labeling: compostability and biodegradability," is the state's restriction on degradability claims. It makes it unlawful to label or advertise a product, including plastic packaging, as "biodegradable," "degradable," "decomposable," "marine degradable," or words to that effect on goods sold in California, unless the claim meets a specific scientific standard recognized in the statute and the supporting evidence is on file. The restrictions concern products generally, not only plastic packaging.

For most CPG packaging the practical effect is straightforward: marine degradable claims on plastic packaging are not legal in California, and biodegradable or degradable claims are restricted to a narrow set of materials and scenarios that are well-documented under the named test methods.

Who PRC §42357 applies to

PRC §42357 applies to any entity that manufactures, sells, offers for sale, or distributes products or packaging in California with one of the restricted claims attached. The brand owner carries the legal duty when the claim appears on its packaging, including when artwork was prepared by a co-packer, contract manufacturer, or marketing agency.

The law applies regardless of where the packaging is printed or filled. If the goods cross the California state line for sale, the claim rules apply.

What is restricted, what is permitted

Restricted claims include "biodegradable," "degradable," "decomposable," "marine degradable," "marine biodegradable," and any synonym or implied claim that the plastic will break down meaningfully under environmental conditions. This sweep is intentional; the legislature wanted to prevent claim language drift around the same underlying assertion.

Compostable claims sit in a separate bucket. They are permitted when the product or packaging meets the relevant ASTM standards (D6400 for compostable plastics, D6868 for compostable coatings on fiber, or successor standards) and is certified accordingly. The "compostable" claim is not the same as "biodegradable" under California law and should not be used interchangeably.

Marine degradable claims, in particular, are effectively prohibited on plastic packaging today because no commonly used plastic material can substantiate that claim under the standards required.

Interaction with SB 343 and the FTC Green Guides

PRC §42357 sits in the same family of California environmental marketing laws as SB 343, the truth-in-labeling rule for recyclability. Where SB 343 governs whether you can call something "recyclable," PRC §42357 governs whether you can call it "biodegradable" or "compostable." A single SKU can be subject to both at the same time.

The FTC Green Guides set the federal floor. PRC §42357 is materially stricter than the Green Guides for plastic packaging. A claim that satisfies the Green Guides may still violate PRC §42357. Compliance teams should treat the Green Guides as necessary but not sufficient for any plastic product sold in California.

A decision tree for any California-bound SKU

Apply this on every California-bound plastic SKU:

1. Does any package component carry a biodegradable, degradable, decomposable, or marine degradable claim, in any wording or visual form?

2. If yes, is there documentation on file proving the material meets the named statutory standard?

3. If no documentation exists, the claim must be removed from California-bound artwork. Re-printing carton stock and updating digital surfaces are part of the cure.

4. If a compostable claim is present, is the material certified to ASTM D6400 or D6868 with current third-party certification documentation on file?

5. If a recyclability claim is also present, run the SB 343 decision tree separately. The two laws stack.

Penalties and enforcement

PRC §42357 violations are enforceable as unlawful business practices under California's broader consumer protection framework. The Attorney General, district attorneys, and certain city attorneys all have authority. Class action exposure under California's consumer protection laws is the bigger practical risk for most brands and is what general counsel typically plan around.

The cure is the same as for the rest of the California claims regime: clean material data, documented evidence for every surviving claim, and a workflow that stops mistaken claims before they print.

Common mistakes

The most expensive mistakes we see on PRC §42357:

• Treating "marine degradable" as a sustainability marketing flourish. It is a regulated claim, and on plastic packaging it is effectively unusable in California today.

• Using "biodegradable" interchangeably with "compostable." They are different legal categories with different evidence requirements.

• Carrying global artwork into the California market unchanged. Other markets have looser rules; California labels often need their own SKU.

• Relying on supplier marketing literature as evidence. The duty to substantiate sits with the brand owner; supplier sell sheets are not certification.

How Packgine handles PRC §42357 review

Your team can review the claims Packgine catalogs on the California-bound SKUs you load, including biodegradable, degradable, marine degradable, and compostable language across the package components you load. Packgine maps each claim to the underlying material and to the supporting evidence on file. Your team can review the claims it flags as lacking evidence for removal or for substantiation work. Teams can use the same dataset for SB 54 fee modeling, SB 343 recyclability review, and PRC §42357 claim review.

Related reading

• California SB 54 Explained: The Packaging EPR Law Reshaping CPG in 2026

• California SB 54: What Producers Owe CalRecycle for CY 2025 Data

• Compostable and Biodegradable Packaging Under EPR: How It's Classified for Fees

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