California compostable compliance means that any product marketed as "compostable" on its packaging, label, or online product listing must be backed by recognized third-party certification, such as BPI certification or demonstrated compliance with ASTM D6400, rather than relying on vague or self-declared claims. Under these rules, unqualified terms like "biodegradable," "degradable," "decomposable," or standalone "eco-friendly" are restricted on product-facing materials unless the product is independently certified and the claim is properly qualified.
What Is California Compostable Compliance?
California compostable compliance refers to the set of labeling standards that govern how compostable products can be described on packaging, product labels, and retail or e-commerce listings sold into the state. The intent behind these rules is straightforward: shoppers should be able to trust that a "compostable" claim on a bag, wrap, or container actually means the product has been tested and verified, not simply marketed with appealing language. This matters because "compostable" is a specific, testable claim, while terms like "biodegradable" or "eco-friendly" are not standardized and can mean almost anything depending on who is using them.
It is important to note that these labeling restrictions apply specifically to product-facing content: the label on the box, the packaging copy, and listings on platforms like Amazon or a brand's own Shopify store. They do not apply to educational or informational content, such as blog articles comparing compostable and biodegradable products, because that content is understood to be informational rather than a point-of-sale claim.
How Does a Product Actually Qualify as Certified Compostable?
A product earns the right to be labeled "certified compostable" by undergoing independent laboratory testing against an established compostability standard, then receiving certification from a recognized body. This is different from a manufacturer simply stating that a product "breaks down" or is "good for the planet." BPI certification, for example, requires independent third-party laboratory testing; it is not a self-declared claim, and products must demonstrate compliance before certification is granted.
The testing itself measures whether a material disintegrates into carbon dioxide, water, and organic matter under defined conditions, without leaving behind toxic residue or microplastics. Critically, compostable materials only begin breaking down when exposed to the specific heat, moisture, and microbial activity that an active composting environment provides. A bag sitting in a kitchen drawer, a landfill, or the ocean is not undergoing composting, regardless of what the label says.
What Certifications and Standards Back Up a Compostable Claim?
Several certifications and standards exist to document compostability, and they are not interchangeable because home and industrial composting involve very different conditions.
- ASTM D6400 (USA): the standard for industrial compostability in the United States. It requires 90% disintegration within 84 days under high-temperature (55-60°C), high-humidity, microbially active commercial composting conditions.
- EN 13432 (EU): the European equivalent standard for industrial compostability, requiring 90% disintegration within 90 days under similar commercial facility conditions.
- BPI certification: verifies compliance with ASTM D6400 through independent lab testing, and is one of the most widely recognized certification marks for industrial compostability in North America.
- TUV Austria OK Compost INDUSTRIAL: another third-party certification confirming a product meets industrial composting disintegration requirements.
- TUV Austria OK Compost HOME: certifies that a product will disintegrate by 90% within 180 days under the lower, ambient temperatures of a standard backyard compost pile, a much slower and less controlled process than industrial composting.
A product that carries only an industrial certification should not be described as "home compostable," and the reverse is also true. GreeneWrap's compostable trash bags, food storage bags, and cling wrap are BPI certified, TUV Austria certified, OK Compost HOME certified, OK Compost INDUSTRIAL certified, and meet both ASTM D6400 and EN 13432 standards, which allows the products to be accurately described in both home and industrial composting contexts.
What Labeling Language Does California Restrict, and What's Safe to Use?
On product labels, packaging, and retail listings, terms such as "biodegradable," "degradable," "decomposable," and standalone claims of "eco-friendly" or "environmentally friendly" are restricted unless the product is certified and the language is properly qualified. These terms are considered too vague on their own because they are not tied to a testable standard or a defined timeframe, which makes it easy for unsubstantiated claims to mislead shoppers.
Language that is considered safe and substantiated includes "certified compostable," "BPI certified," "ASTM D6400 compliant," and "EN 13432 compliant." The terms "home compostable" and "industrially compostable" are also acceptable, but only when paired with the specific certification that supports them, such as referencing TUV OK Compost HOME for a home compostability claim, or BPI/ASTM D6400 for an industrial one. This distinction matters because a product that disintegrates in a commercial facility at 55-60°C may behave very differently in a backyard compost bin at ambient temperature.
It's worth noting again that this restriction is specific to product-facing content. Informational articles discussing the difference between biodegradable and compostable products, or explaining why biodegradable is considered a vague claim, are standard educational content and are not affected by these labeling rules.
How Can Shoppers Verify a Compostable Claim Themselves?
The most reliable way to verify a compostable claim is to look for a specific certification mark and standard reference on the packaging, rather than taking a general descriptive word at face value. A product that lists "BPI certified" or "OK Compost INDUSTRIAL" alongside a reference to ASTM D6400 or EN 13432 has been through independent testing. A product that only says "eco-friendly" or "biodegradable" with no certification attached has not necessarily been tested against any standard at all.
It also helps to check whether the claim distinguishes between home and industrial composting. A legitimate compostable product will specify which environment it's designed for, since the conditions, timeframes, and microbial activity required for each are different. If a label makes a composting claim without specifying home or industrial, and without naming a certification body, that is a signal to look more closely before assuming the product will perform as expected in a backyard bin or municipal green-bin program.
What Should You Look For When Choosing Compostable Trash Bags?
When selecting compostable trash bags, the certification marks on the packaging matter more than marketing language. Look for BPI certification, OK Compost HOME and OK Compost INDUSTRIAL certification, TUV Austria certification, and compliance with ASTM D6400 and EN 13432. These marks indicate the bag has been independently tested, not just described as "compostable" by the manufacturer.
Sizing and intended use also matter in practice. Smaller bags, such as 1-2 gallon or 13 gallon sizes, are typically suited to kitchen food scrap collection, while bags in the 50 to 95 gallon range are heavy-duty options suited to yard waste or contractor and job-site cleanup. All of these should carry the same underlying certifications if they are genuinely compostable, regardless of size. If a product is also marketed as free of PFAS, it's worth noting that PFAS-free status varies by manufacturer and should be confirmed directly rather than assumed across the industry; some compostable products may contain PFAS, so checking certification and manufacturer confirmation is the safer approach. GreeneWrap products, for example, are confirmed PFAS free and fluorine free by the manufacturer, but this applies specifically to GreeneWrap and should not be assumed for other brands.
Finally, remember that certified compostable bags are designed for active composting environments, not for ordinary trash disposal. Like all organic materials, compostable bags decompose more slowly in landfill conditions where oxygen and moisture are limited, so the environmental benefit of a certified compostable bag depends on where it actually ends up after use, whether that's a home compost bin or a municipal or industrial composting program.
FAQ
Does California's labeling rule apply to blog content or only to product packaging?
It applies to product-facing content only, meaning packaging, labels, and retail or e-commerce product listings. Educational or comparative blog content, such as an article explaining the difference between biodegradable and compostable products, is not restricted in the same way.
Is "home compostable" the same as "industrially compostable" under these labeling standards?
No. Home compostability is certified under the TUV OK Compost HOME standard and reflects ambient-temperature backyard conditions, with 90% disintegration expected within 180 days. Industrial compostability is certified under ASTM D6400 or EN 13432 and reflects high-temperature commercial facility conditions, with 90% disintegration within 84 to 90 days. A product should only be labeled with the composting environment its certification actually supports.
Will a certified compostable bag break down if it ends up in a landfill?
Compostable bags are designed for active composting environments, not landfills. Like all organic materials, compostable bags decompose more slowly in landfill conditions where oxygen and moisture are limited, so certification for composting does not translate into a landfill breakdown guarantee.
What's the difference between a "compostable" claim and a "biodegradable" claim?
"Compostable" is tied to a specific, testable standard, such as ASTM D6400 or EN 13432, with defined timeframes and disintegration percentages verified by independent certification. "Biodegradable" has no standardized testing requirement or timeframe behind it, which is why it is treated as a vague, unsubstantiated claim on product labels unless it is paired with actual certification data.
How can I tell if a compostable product's certification is legitimate?
Look for a named certification body, such as BPI, TUV Austria, or OK Compost, along with a reference to a specific standard like ASTM D6400 or EN 13432. Legitimate certifications involve independent third-party laboratory testing rather than a manufacturer's own description, and the certifying body can typically confirm a product's status if there is any doubt.