New Prop 65 Labeling Requirements: Short-Form Warning and 2028 Deadline

The new Prop 65 short-form warning requirements took effect January 1, 2025, and the headline change is simple: a short-form warning can no longer be generic. It must name at least one listed chemical causing the exposure. California is allowing a three-year transition, so products manufactured and labeled under the old short-form format before January 1, 2028, can still be sold in the state after that date. Any new labeling applied on or after January 1, 2028, has to meet the updated content rules.¹

This is the most significant change to Prop 65 label content since the 2018 overhaul, and it affects every business that has been using the condensed short-form format for consumer products sold in California.

What the New Short-Form Warning Must Say

Under the old rule, a compliant short-form warning could say “Cancer and Reproductive Harm — www.P65Warnings.ca.gov” without ever telling the consumer which chemical was involved. That is no longer enough.

The updated regulation gives businesses several approved phrasings. For a cancer-listed chemical, the label can read “Cancer risk from exposure to [chemical name]” or “Can expose you to [chemical name], a carcinogen.” Reproductive toxicants follow the same pattern, substituting “reproductive harm” or “reproductive toxicant.” When a product contains chemicals listed for both endpoints, the warning has to address both, and it can name different chemicals for each. Every version still ends with a reference to www.P65Warnings.ca.gov.²

You are naming a chemical, not the whole list. A product with a dozen listed chemicals only needs one to appear in the short-form warning for each hazard endpoint. Which one you pick is a compliance judgment, and most businesses select a chemical they can defend on testing and exposure data.

The 2028 Deadline and What “Compliance” Looks Like in the Meantime

Three years sounds generous. It goes fast when the work involves reformulating labels across a full product catalog, updating artwork, coordinating with printers, and pushing new packaging through the supply chain.

The regulation draws the line at manufacturing and labeling date, not sale date. A product that was manufactured and labeled with the old short-form warning before January 1, 2028, can continue to be sold in California after that date. A product manufactured or relabeled on or after January 1, 2028, needs the new content.¹

For online sales, retailers get a 60-day window to update posted warnings after receiving notice and materials from the manufacturer, as long as the underlying sale occurs before the 2028 cutoff. After that, online warnings need to already be current.

Businesses that want to move now do not have to wait. The new short-form phrasings are already valid safe-harbor language. Nothing in the regulation forces you to use up the transition; if you can update sooner, do it.

Format Elements the Short-Form Warning Still Needs

Naming a chemical is the new piece. The rest of the format rules carry over.

Every compliant warning still needs a black exclamation point inside a yellow equilateral triangle with a bold black outline, placed to the left of the text and sized no smaller than the height of the word “WARNING.” If the label is not printed in color, a black-and-white version of the symbol is acceptable.³

The word “WARNING” appears in all capitals and bold. Businesses can also use “CA WARNING” or “CALIFORNIA WARNING.” Short-form text on a product label must appear in type no smaller than 6-point font.⁴

If any other consumer information on the product is provided in a language besides English, the Prop 65 warning must also appear in that language. OEHHA publishes sample translated warnings for businesses to use.⁵

Placement rules also stayed the same. In a physical store, the warning can go directly on the product label, on a shelf tag, or on a prominently displayed sign near the product. For online sales, the warning can appear on the product display page, in a clearly marked hyperlink using “WARNING,” “CA WARNING,” or “CALIFORNIA WARNING,” or elsewhere on the site as long as the consumer sees it before completing checkout. A warning tucked into unrelated site content does not qualify.⁴

OEHHA has taken the position that internet purchases actually require two warnings: one before purchase, on the website, and another before exposure, on or with the delivered product. The safer path is to plan for both.

Who Has to Put the Warning on the Product

Prop 65 puts the initial burden on manufacturers, producers, importers, and distributors. Any of them can satisfy the duty by labeling the product directly or by sending written notice and warning materials to the retailer or the next business in the chain. Once a retailer gets those materials, the retailer becomes responsible for actually posting or displaying them.⁶

Retailers carry direct warning responsibility in a limited set of situations:

The product is sold under a brand or trademark the retailer owns or licenses.
The retailer knowingly added or created a listed chemical in the product.
The retailer covered, obscured, or altered a warning the manufacturer placed on the product.
The retailer received warning materials from the manufacturer but sold the product without displaying them.
The retailer knows about the exposure, and no upstream party has a California agent for service of process or a California place of business.

Businesses in the chain can also use written agreements to reallocate responsibility, and those contracts override the default rules as long as the consumer ends up with a compliant warning before exposure.⁶

Selling into California from another state does not get you out of this. If you ship consumer products into California through a website or catalog, Prop 65 applies to you. Smaller e-commerce sellers who ship nationwide are the ones most often caught by surprise.⁷

Who Is Exempt

Two categories of business are fully exempt from Prop 65’s warning and discharge rules. Companies with fewer than 10 employees (counting all full-time and part-time employees as of the date the exposure occurs) are exempt, and so are federal, state, and local government agencies.⁸ The small-business exemption is narrower in practice than it looks on paper, because larger customers often require warning compliance by contract regardless of headcount.⁷

Two other boundary rules are worth knowing before you decide a product needs a warning. Warnings are not required for exposures within the first 12 months after a chemical is added to the Prop 65 list, and they are not required for exposures where federal law preempts state warning authority.⁹ Exposures below the established safe-harbor level for a given chemical also do not require a warning, though when no safe-harbor level exists for a listed chemical, the business carries the burden of showing that the exposure poses no significant risk.¹⁰

What Noncompliance Costs

Most Prop 65 enforcement does not come from the state. It comes from private citizens and their attorneys, who are allowed to sue “in the public interest” against businesses that fail to provide adequate warnings.

Before filing, a private enforcer has to give 60 days’ written notice to the alleged violator, the California Attorney General, and the local district attorney or city attorney where the violation supposedly occurred. A failure-to-warn notice must include a certificate of merit stating that the filer consulted with someone with relevant expertise, reviewed the exposure facts, and believes the case has merit. The 60-day window gives the government the option to take over the case, though in practice most notices proceed as private actions.¹¹

Penalties can reach $2,500 per day per violation. A single product distributed across many retail locations over several months can accumulate a large per-day count quickly.¹² Of the penalties collected, 75 percent goes to the state and 25 percent goes to the private enforcer. The statute also allows recovery of attorney fees where the action produced a significant public benefit, and those fees often exceed the penalty itself.¹¹

Courts weigh several factors in setting penalties, including the severity of the violation, the violator’s economic situation, whether the business took good-faith compliance steps, and the deterrent value of the penalty. A company that acted quickly to correct labels and can document its efforts will land in a very different place than one that ignored the change.

Which is the practical case for treating January 1, 2028, as a working deadline rather than a distant one. Prop 65 plaintiffs read the regulations too, and a short-form warning that still lacks a chemical name after that date is the kind of easy target that drives enforcement volume.

1
Office of Environmental Health Hazard Assessment. Proposition 65 Clear and Reasonable Warnings – Safe Harbor Methods and Content
2
New York Codes, Rules and Regulations. California Code of Regulations Title 27, Section 25603 – Consumer Product Exposure Warnings Content
3
Legal Information Institute. California Code of Regulations Title 27, Section 25603 – Consumer Product Exposure Warnings Content
4
Legal Information Institute. California Code of Regulations Title 27, Section 25602 – Consumer Product Exposure Warnings Methods of Transmission
5
Proposition 65 Warnings. Sample Warnings and Translations for Businesses
6
Legal Information Institute. California Code of Regulations Title 27, Section 25600.2 – Responsibility to Provide Consumer Product Exposure Warnings
7
Proposition 65 Warnings. Frequently Asked Questions for Businesses
8
Office of Environmental Health Hazard Assessment. Businesses and Proposition 65
9
California Legislative Information. California Health and Safety Code Section 25249.10
10
Office of Environmental Health Hazard Assessment. Proposition 65 No Significant Risk Levels (NSRLs) and Maximum Allowable Dose Levels (MADLs)
11
California Legislative Information. California Health and Safety Code Section 25249.7
12
Proposition 65 Warnings. What Are the Penalties for Violating Proposition 65