Prop 65 on Amazon comes down to two documents: California’s warning regulations, which put the warning duty mainly on the manufacturer, producer, packager, importer, supplier, or distributor, and Amazon’s own help page, which tells every seller to “Determine if the product needs a Prop 65 warning” and submit it through the listing’s Compliance attributes (Amazon Seller Central, G202141960, checked 2026-10-05). The same Amazon page states that this applies “even if you have fewer than 10 employees, and even if someone else is selling the same product.”
Online, the regulation accepts a warning on the product display page, a clearly marked “WARNING” hyperlink, or a warning shown before checkout. The old one-line label (“Cancer – www.P65Warnings.ca.gov.”) stays valid only for products manufactured and labeled before January 1, 2028.
This is a compliance-orientation guide, not legal advice. Every rule below is quoted from the statute, the regulations, or Amazon’s help page with the date it was checked.
Fact Block: What These Claims Rest On
| Source (all checked 2026-10-05) | What it establishes |
|---|---|
| H&S Code § 25249.6, § 25249.7, § 25249.11 — California Legislature | Warning duty, penalties, 60-day notice, 10-employee carve-out |
| 27 CCR § 25600.2 — via Cornell LII | Manufacturer vs retail seller responsibility |
| 27 CCR § 25602 and § 25603 — via Cornell LII | Internet warning methods; full and short-form wording; the 2028 cut-off |
| California Proposition 65 (Prop 65) — Amazon Seller Central help | What Amazon asks sellers to submit and how |
The regulator’s sites, p65warnings.ca.gov and oehha.ca.gov, refused automated access on 2026-10-05, so the regulation text here is the version reproduced by Cornell’s Legal Information Institute, including its amendment history.
Does Your Product Need a Prop 65 Warning?
The statute is one sentence: “No person in the course of doing business shall knowingly and intentionally expose any individual to a chemical known to the state to cause cancer or reproductive toxicity without first giving clear and reasonable warning to such individual, except as provided in Section 25249.10” (H&S Code § 25249.6).
The trigger is exposure to a listed chemical, not the product category. Amazon’s help page says OEHHA “publishes the listed chemicals, which includes more than 850 chemicals” (checked 2026-10-05).
For a reseller, the answer usually arrives from upstream: a manufacturer that has decided a warning is needed either prints it on the label or sends a written notice under 27 CCR § 25600.2(b). Three questions frame the decision:
- Does the product, its packaging, or a component contain a listed chemical? That is a supplier-documentation and testing question.
- Has anyone upstream already given you a warning or written notice? If yes, § 25600.2(d) makes the retail seller responsible for placing and maintaining it, including online.
- Do you sell under your own brand, or did you change the product? Those facts can shift the duty onto you.
Penalties are statutory: a violator “is liable for a civil penalty not to exceed two thousand five hundred dollars ($2,500) per day for each violation” (H&S Code § 25249.7(b)(1)). A private action must be “commenced more than 60 days from the date that the person has given notice” (§ 25249.7(d)(1)).
Who Is Responsible: Manufacturer vs Retailer
27 CCR § 25600.2(a) says the Act requires the agency “to minimize the burden on retail sellers of consumer products, to the extent practicable,” except where the retailer itself introduced the chemical.
The upstream chain carries the default duty. Under § 25600.2(b), “The manufacturer, producer, packager, importer, supplier, or distributor of a product” complies with a warning on the label or labeling, or with a written notice to the buyer’s authorized agent. The notice must identify the product (a UPC works), include “warning language for products sold on the internet,” and “Be renewed annually during the period in which the product is sold in California by a retail seller.” Receipt must be confirmed electronically or in writing (§ 25600.2(c)(1)).
The retail seller’s duty is narrower. Section 25600.2(d) makes the retailer “responsible for the placement and maintenance of warning materials, including warnings for products sold over the internet,” that it receives. Section 25600.2(e) lists the only five cases in which the retailer owns the warning itself:
| § 25600.2(e) | Retail seller is responsible when… |
|---|---|
| (1) | It sells “under a brand or trademark that is owned or licensed by the retail seller or an affiliated entity” |
| (2) | It knowingly introduced a listed chemical into the product |
| (3) | It “covered, obscured or altered a warning label” |
| (4) | It received warning materials and sold “without conspicuously posting or displaying the warning” |
| (5) | It has actual knowledge of the exposure and no upstream business is covered by the Act and reachable in California |
Item (1) is the private label line. Item (5) is the importer line: with an overseas supplier that has no California agent or place of business, a seller who knows about the exposure can end up holding the warning.
Two more provisions matter. Section 25600.2(g) requires a retailer, on written request from the agency, a prosecutor, or a person who served a 60-day notice, to “promptly provide the name and contact information” of upstream parties. Section 25600.2(i) lets the parties reallocate the duty by “a written agreement,” provided the consumer still gets a compliant warning before exposure.
The regulation speaks of “retail sellers” and does not mention marketplaces. Amazon’s help page settles the practical question for its store: it puts the determination and submission on the seller.
What Amazon Asks Sellers to Do
Amazon’s Prop 65 help page, marked as applying to selling in the United States (checked 2026-10-05), gives these instructions for all new and existing listings:
- Determine whether the product needs a Prop 65 warning.
- Provide it “using the instructions on this page (and not in any other way, such as by email).”
- If you are not the manufacturer, pass on the warning received from the manufacturer or “from anyone else that sold or transferred the product to you.”
- Do not send labels, shelf signs, or tags “unless we otherwise instruct you to do so in writing.”
- Add warnings to child SKUs; a parent-SKU warning returns “an error message and the submission will fail.”
- Contact Selling Partner Support “if a court requires you to provide a custom Prop 65 warning for your product.”
Where the fields are. For a single listing: Inventory, Add a Product, then the Compliance tab, where you pick a “California Proposition 65 Warning Type” and, where needed, chemical names. For bulk: the Compliance group of an advanced template from Add Products via Upload. Sellers using custom feeds “must supplement those listings’ information” through one of those methods.
| Group | Amazon warning types (checked 2026-10-05) |
|---|---|
| Content-based | Food, Furniture, Chemical (cancer, reproductive, or both) |
| Label already printed | On Product Cancer, On Product Reproductive, On Product Combined Cancer and Reproductive |
| Category-specific | Alcoholic Beverage, Raw Wood, Passenger or Off-road Vehicle, Recreational Vessel, Diesel Engine |
The last two groups allow no chemical name. The “On Product” types display the older short-form wording, such as “Cancer – www.P65Warnings.ca.gov/". On 2026-10-05 the page listed no type for the new short-form wording that took effect January 1, 2025, and its background section still describes regulations “effective on August 30, 2018.” If your label uses the new wording, ask Selling Partner Support which type to pick and keep the reply.
See Manage Your Compliance for Amazon’s other document requests, and hazmat review if the same chemistry triggers dangerous-goods classification.
Internet Sale Warning Rules
For online sales, 27 CCR § 25602(b)(1) accepts a warning that meets the content rules in § 25603 and is delivered by one or more of these methods:
- “a warning on the product display page,” or
- “a clearly marked hyperlink using the word “WARNING” or the words “CA WARNING” or “CALIFORNIA WARNING” on the product display page that links to the warning,” or
- “an otherwise prominently displayed warning provided to the purchaser prior to completing the purchase.”
The subsection adds: “the warning is not prominently displayed if the purchaser must search for it in the general content of the website.” Where the label uses the short form, the web warning may reuse that content.
On Amazon, the Compliance attribute is how the seller supplies the text; Amazon controls where it renders. The internet rule applies in addition to the label, not instead of it, and § 25602(d) requires a warning in any non-English language used for consumer information on the label or sign, alongside English.
The Short-Form Warning and the January 1, 2028 Transition
Amendments to §§ 25602 and 25603, filed 11-26-2024 and operative 1/1/2025 (amendment notes via Cornell LII), rewrote the short-form label. It still needs the yellow triangle symbol and “WARNING:”, “CA WARNING:”, or “CALIFORNIA WARNING:” in bold capitals, and must now name a chemical.
| Endpoint | Old short form, § 25603(c) | New short form, § 25603(b)(3), first option |
|---|---|---|
| Cancer | “Cancer – www.P65Warnings.ca.gov.” | “Cancer risk from exposure to [name of chemical]. See www.P65Warnings.ca.gov.” |
| Reproductive harm | “Reproductive Harm – www.P65Warnings.ca.gov.” | “Risk of reproductive harm from exposure to [name of chemical]. See www.P65Warnings.ca.gov.” |
| Both | “Cancer and Reproductive Harm – www.P65Warnings.ca.gov.” | “Risk of cancer from exposure to [name of chemical] and reproductive harm from exposure to [name of chemical]. See www.P65Warnings.ca.gov.” |
Each endpoint also has a second option, such as “Can expose you to [name of chemical], a carcinogen. See www.P65Warnings.ca.gov.” On a label, the short form may not appear “in a type size smaller than 6-point type” (§ 25602(a)(4)).
The transition follows the product date, not the sale date. Section 25603(c) reads: “A short-form warning on a product manufactured and labeled prior to January 1, 2028, may use the following content regardless of when the product is sold to a consumer.” Old-label stock can keep selling after 2027.
Retailers get a 60-day window online. Under § 25602(b)(2), “For internet purchases made before January 1, 2028,” a retail seller is not responsible for posting the updated warning “until 60 calendar days after the retailer receives” it.
For a private label seller, the practical step is to update packaging artwork before 2028 production runs, then switch the Amazon warning type when the new stock goes live. Label reprints after a safety problem are a separate process; see product recalls for sellers.
The Fewer-Than-10-Employees Exemption
The statute’s carve-out: “‘Person in the course of doing business’ does not include any person employing fewer than 10 employees in his or her business” (H&S Code § 25249.11(b)).
It does not carry over to Amazon’s store. Amazon’s help page says sellers are responsible for adding a warning “even if you have fewer than 10 employees, and even if someone else is selling the same product” (checked 2026-10-05). A solo seller can sit outside the statute and still need the warning attribute to keep listing.
Prop 65 Checklist for Amazon Sellers
- For each ASIN, ask the manufacturer or importer in writing whether a warning or § 25600.2(b) notice applies, and file the reply.
- If you sell under your own brand, treat the warning decision as yours (§ 25600.2(e)(1)).
- Enter the warning type and chemical names on every child SKU.
- Match any “On Product” type to what is printed on the label.
- Keep supplier contact details ready for a § 25600.2(g) request.
- Track annual renewal of written notices (§ 25600.2(b)(4)).
- Schedule label artwork changes before production dated January 1, 2028 or later.
Related reading: GPSR compliance covers the EU version of “who is responsible,” and product liability insurance covers the coverage side.
Frequently Asked Questions
Does Amazon require a Prop 65 warning on every product?
No. Amazon’s help page asks sellers to “Determine if the product needs a Prop 65 warning,” and for listings flagged by Amazon Product Compliance says “If your listings do not require a warning, no further action is required from you” (checked 2026-10-05).
Who is responsible for Prop 65 warnings, the manufacturer or the Amazon seller?
Under 27 CCR § 25600.2(b), the default duty sits with the manufacturer, producer, packager, importer, supplier, or distributor. The retail seller places warnings it receives (§ 25600.2(d)) and owns the warning in the five cases in § 25600.2(e), including selling under its own brand.
How do I add a Prop 65 warning to an Amazon listing?
Through the Compliance tab of the listing, or the Compliance group of an advanced upload template, by choosing the California Proposition 65 Warning Type and chemical names. Amazon does not accept email submissions.
Can I keep selling products with the old “Cancer – www.P65Warnings.ca.gov” label after 2027?
27 CCR § 25603(c) allows the old short form on products “manufactured and labeled prior to January 1, 2028” regardless of when they are sold.
Conclusion
Prop 65 compliance on Amazon is mostly a paperwork chain: get the warning or notice from upstream, enter it on the right child SKUs, and re-check when the label changes. The decision becomes yours when the brand is yours. Put January 1, 2028 on the packaging calendar now, because the new short-form labels are tied to the manufacturing date.