California Prop 65 warnings for electronics

Author Hugues Orgitello Last updated 30 August 2026 ~17 min read

Guide · US market chemical warnings

California Proposition 65, formally the Safe Drinking Water and Toxic Enforcement Act of 1986, is one of the most misunderstood compliance questions for a company selling electronics into the United States. It is not a ban, it does not restrict any substance, and it is not a federal rule. It is a California state right-to-know law that requires a warning before a person is exposed to a listed chemical above a defined level. For electronics that means lead, phthalates, cadmium and a handful of other common materials can trigger a label, even on a product that passes RoHS and REACH without a problem. This page explains what Prop 65 actually requires, how the safe-harbor warning is built, what the NSRL and MADL thresholds mean, and why the real pressure comes from private lawsuits rather than a regulator.

What Proposition 65 is, and what it is not

Proposition 65 was adopted by California voters in 1986. It is codified in the California Health and Safety Code and administered by OEHHA, the Office of Environmental Health Hazard Assessment. Its mechanism is narrow and specific: the State maintains a list of chemicals known to cause cancer, birth defects, or other reproductive harm, and a business may not knowingly expose a person in California to a listed chemical without first giving a "clear and reasonable warning".

The single most important thing to understand is the contrast with the restriction regimes:

Regime	Type	What it controls	Compliance route
Proposition 65	Warning / right-to-know	Exposure to a listed chemical	Warn, or prove exposure is below the safe-harbor level
RoHS	Substance restriction	Concentration in the homogeneous material	Keep the substance under the threshold
REACH (restriction, authorisation)	Substance restriction / authorisation	Presence and use of the substance	Remove, reduce, or get authorisation

A product can contain a listed chemical and remain perfectly legal to sell in California, provided either that the exposure stays below the relevant threshold, or that an adequate warning is given. This is fundamentally different from RoHS, where exceeding 0.1 percent of lead in a homogeneous material makes the product non-compliant regardless of any exposure, and from REACH restrictions, which cap or forbid the substance itself.

Why it matters outside California

Strictly, Prop 65 applies to products sold or distributed in California by businesses with ten or more employees. In practice it behaves like a US-wide requirement. National retailers and online marketplaces do not maintain separate California inventory, so they push the requirement onto their suppliers for all units. A manufacturer that wants distribution through a large US retailer is usually contractually required to treat Prop 65 as a nationwide label decision. That is why a guide aimed at electronics manufacturers treats it as a standard US-market question, not a regional curiosity.

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The OEHHA list of chemicals

OEHHA publishes and maintains the Proposition 65 list, which now contains more than 900 chemicals. A chemical is added when it is identified as a carcinogen or as a reproductive toxicant through one of the listing mechanisms defined in the law (for example, identification by an authoritative scientific body, or a determination by the State's qualified experts). The list is revised regularly, and a newly listed chemical generally carries a grace period (commonly twelve months) before the warning requirement applies, which makes monitoring the list a continuing task rather than a one-off check.

For electronics and their accessories, the chemicals that come up again and again are these:

Chemical	Endpoint	Where it appears in electronics
Lead and lead compounds	Cancer and reproductive	Solder, brass connectors and contacts, PVC cable stabilisers, some alloys, weights
DEHP, DINP and other phthalates	Cancer and/or reproductive	Flexible PVC cables, cords, jackets, grips, soft-touch overmoulds
Cadmium and cadmium compounds	Cancer and reproductive	Some platings and pigments, older solders, certain batteries
Bisphenol A (BPA)	Reproductive	Some polycarbonate plastics, thermal printer paper, some coatings
Nickel and nickel compounds	Cancer	Plating on connectors, casings, contacts
Antimony trioxide	Cancer	Synergist in flame-retardant plastics
Brominated flame retardants (various)	Cancer	Enclosures, PCB laminates, cable insulation

Lead in PVC cable jackets and DEHP in flexible cords are the two classic triggers for consumer electronics: a power cable, a USB lead or a charger cord can carry a Prop 65 exposure even when the device itself is clean. The authoritative reference is always the current OEHHA list, not a vendor summary, because vendor lists lag behind additions.

The clear and reasonable warning

The law requires a "clear and reasonable warning", but it does not force one exact wording. Instead, OEHHA defines a set of "safe-harbor" warnings: if you use them, the warning is deemed clear and reasonable by definition. You may use a different warning, but then you carry the burden of arguing it was adequate, which is a weak place to be in litigation. In practice almost everyone uses the safe-harbor format.

Anatomy of the safe-harbor consumer-product warning

The standard safe-harbor warning for a consumer product has a defined structure:

• The yellow triangle symbol containing a black exclamation mark (a warning symbol). It may be black and white if no other color appears on the label.
• The word WARNING in capital letters, in bold.
• A statement that the product can expose you to a chemical, naming at least one listed chemical for each relevant endpoint. If the product exposes to a carcinogen, name a carcinogen; if it also exposes to a reproductive toxicant, name one of those too.
• A reference to the OEHHA warnings website, p65warnings.ca.gov.

A typical long-form wording reads, in substance: "WARNING: This product can expose you to chemicals including lead, which is known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to p65warnings.ca.gov." The exact endpoint phrasing depends on which list the named chemical is on.

Short-form warnings

OEHHA also allows a short-form warning on the product label, a compressed version meant for labels where space is tight. It still requires the symbol, the word WARNING, an indication of the endpoint and the website reference, and since 1 January 2025 a newly designed short form must also name a listed chemical. Product manufactured and labelled before 1 January 2028 keeps the old content; the section below sets out what the amended short form has to say and how long an existing label stays lawful.

Where the warning has to be

The warning has to be given before the exposure, by a method reasonably calculated to reach the person. For consumer products that usually means an on-product label, on-package text, or a clearly associated shelf sign, plus, for e-commerce, a warning displayed on the product web page before purchase. A warning hidden inside the manual after the sale is not "before exposure" and is not adequate.

The amended short-form warning and the 2028 transition

OEHHA rewrote the short-form rules in 2024. The amendments to sections 25601, 25602 and 25603 of Title 27 of the California Code of Regulations were filed on 26 November 2024 and are operative from 1 January 2025 (Register 2024, No. 48). The substantive change states easily and implements slowly: a short-form warning must now name a listed chemical, exactly as the long form always had to. The old endpoint-only short form is not forbidden, but it survives only through a transitional subsection with a fixed cut-off date.

Element	Old short form, now section 25603(c)	Amended short form, section 25603(b)
Warning symbol	Yellow triangle with black exclamation mark, per 25603(a)(1)	Unchanged, still 25603(a)(1)
Signal word	WARNING: in capitals and bold	WARNING:, CA WARNING: or CALIFORNIA WARNING: in capitals and bold
Chemical name	Not required	Required, at least one listed chemical for each endpoint warned
Body text	The endpoint alone, Cancer, Reproductive Harm or Cancer and Reproductive Harm, followed by www.P65Warnings.ca.gov	A defined sentence naming the chemical, for example Cancer risk from exposure to [name of chemical]. See www.P65Warnings.ca.gov.
Type size, per 25602(a)(4)	Whole warning no smaller than the largest type size used for other consumer information on the product, never below 6-point	Type size satisfying the conspicuousness rule of 25601(c), never below 6-point

What the amended short form has to say

The naming requirement did not come from section 25603 alone. Section 25601(b) has always required the name of one or more listed chemicals in the text of a warning, with a name for each endpoint where both cancer and reproductive toxicity are warned, unless one named chemical is listed for both. What it used to open with was "Except as provided in Section 25603(c)", and that cross-reference was the exemption the short form lived on. The 2024 amendment replaced the carve-out with "Except as otherwise specified in Section 25607 et seq." and repealed the old 25603(c), the subsection that said a short-form warning need not name a chemical. Naming is now the general rule, and the short form no longer sits outside it.

Section 25603(b) does not leave the wording open. It sets out two permitted sentences for each endpoint case, and a compliant short form uses one of them as written with the chemical name filled in. For a carcinogen the choice is between Cancer risk from exposure to [name of chemical]. See www.P65Warnings.ca.gov. and Can expose you to [name of chemical], a carcinogen. See www.P65Warnings.ca.gov. Parallel pairs exist for a reproductive toxicant, for both endpoints together, and for a chemical listed for both.

The type-size rule moved the other way. Amended section 25602(a)(4) requires a short-form warning to be provided "in a type size that complies with Section 25601(c)" and keeps the floor: "in no case shall the warning appear in a type size smaller than 6-point type". Section 25601(c) is the conspicuousness rule, and the earlier requirement that the entire warning be no smaller than the largest type size used for other consumer information on the product was deleted. Do not read that as permission to shrink the label. The final statement of reasons published by OEHHA is blunt about the trade: "a short-form warning on a large appliance will need to be presented in a much larger type size than is currently being used". Six-point type in the corner of a large enclosure will not satisfy 25601(c).

How long an existing short-form label stays lawful

This is the question that decides whether label artwork has to change this year, and the regulation answers it by date of manufacture, not date of sale. Section 25603(c), as amended, opens:

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:

Three consequences follow, and together they are more generous than the "rules were tightened" headline suggests.

• The new content may be used immediately. OEHHA records that the amended short-form language "can be used immediately upon the adoption of the regulation". Nothing obliges a brand to wait, and nothing obliges it to switch every product on the same day.
• Old labels applied before the cut-off stay good indefinitely. The sell-through is open-ended. OEHHA states it directly: the unlimited sell-through "applies to any product that is 'manufactured and labeled'" within the three-year window, and "it does not matter when that product is eventually sold to a consumer". There is no relabelling duty, no recall, and no date by which channel stock has to be cleared.
• Units manufactured and labelled on or after 1 January 2028 need the new content. From that date the old wording is no longer deemed clear and reasonable for newly labelled product. The alternatives are the amended short form of 25603(b), the full-length warning of 25603(a), or another method listed in 25602.

The protection attaches to labelled product, not to label stock. OEHHA refused a request to extend the sell-through to preprinted labels and packaging held in inventory, reasoning that it "would make enforcement more difficult and incentivize businesses to stock up on preprinted labels that could be used for many years". A reel of unused short-form labels bought in 2027 is worth nothing in 2028; a pallet of chargers already carrying them can be sold long afterwards.

The online listing has its own clock. Under section 25602(b)(2), for internet purchases made before 1 January 2028 a retail seller is not responsible under section 25600.2(e)(4) for posting the updated warning online until 60 calendar days after it receives a warning or a written notice under section 25600.2(b) and (c) that replaces 25603(c) content with 25603(b) content. For a brand the reading is practical: the retailer's 60 days do not start until you notify it in writing, and once they start the window is 60 days, not three years, so send the new wording with the notice rather than after it.

What this means for existing label artwork

The amendment turns a labelling decision into a bill-of-materials decision. An old short-form label could be applied without knowing which chemical triggered it, which is exactly why the format spread far beyond the small packages OEHHA designed it for. The amended one cannot: the text has to name a chemical for each endpoint being warned, so somebody has to establish whether the honest answer is lead, DEHP or something else, for every product carrying the label. That is the material declaration and exposure work described below, brought forward by a deadline. Three years is not long for a catalogue with shared artwork, many suppliers and long tooling lead times, and the clock started on 1 January 2025.

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NSRL, MADL and the safe-harbor levels

A warning is only required when the exposure is above a level that matters. Prop 65 defines two families of safe-harbor exposure levels.

Level	Applies to	Meaning
NSRL (No Significant Risk Level)	Carcinogens	Daily exposure below which the lifetime cancer risk is treated as not significant
MADL (Maximum Allowable Dose Level)	Reproductive toxicants	Daily exposure below which no observable reproductive effect is expected, with a built-in safety factor

OEHHA publishes numeric NSRLs and MADLs for many listed chemicals, expressed as a daily dose (for example micrograms per day). The principle is straightforward: if the realistic daily exposure a user receives from your product stays below the relevant level, no warning is required for that chemical. If it can exceed the level, you warn.

The trap is in the burden of proof. Under the law, once a listed chemical is present, the business bears the burden of showing that the exposure is below the safe-harbor level. Establishing that requires an exposure assessment: how much of the chemical migrates or is released, by what route (oral, dermal, inhalation), under reasonably foreseeable use, over a relevant time. That analysis costs money and expertise. For a low-value accessory, many companies decide it is cheaper to warn than to fund the assessment, which is exactly why warnings proliferate. This guide does not quote specific NSRL or MADL numbers, because they are chemical-specific, are revised by OEHHA over time, and must be read from the current official table for the chemical in question.

Exposure pathways for electronics

What makes an electronic product different from, say, a food container is the mix of exposure routes. A user does not eat a charger, but they handle it daily, and a child may mouth a cable. The three routes the assessment has to consider are these:

• Dermal contact. The dominant route for cables, cords, grips, wearable bands and handheld housings. Lead and phthalates can transfer to skin from soft PVC and from plated surfaces handled repeatedly. The realistic contact time and surface area drive the dose.
• Oral / hand-to-mouth. Relevant where small parts, cords or accessories may be mouthed, especially for products plausibly used by or around children. Migration into saliva is the model used.
• Inhalation. Less common for solid electronics, but relevant for products that heat, off-gas, or are used in enclosed spaces, and for certain coatings or flame-retardant systems.

Because the same part can present more than one route, an assessment is done per chemical per pathway, and the warning decision follows the worst case. A connector that a user touches for seconds a day is a different calculation from a wristband worn against the skin for hours, even if both are plated with the same metal.

When an assessment is worth funding

A reasonable rule of thumb: fund the exposure assessment when the product line is high volume, long-lived, or premium enough that a Prop 65 warning would hurt the brand or the listing, and when the suspected chemical is a single, well-characterised one with a published safe-harbor level. Default to a warning when the product is a low-value accessory, when several listed chemicals are present at once, or when the supply chain cannot give a reliable concentration. The assessment is an investment that pays off across a product family; a one-off SKU rarely justifies it.

Enforcement: the 60-day notice and private plaintiffs

Proposition 65 is enforced very differently from a typical regulatory scheme, and this is what makes it a litigation risk rather than an inspection risk.

1. Public enforcement exists but is the minority. The California Attorney General, district attorneys, and certain city attorneys can bring actions.
2. Private enforcement dominates. The statute lets any person act "in the public interest". Private plaintiffs, often the same specialised plaintiff firms, bring the large majority of cases.
3. The 60-day notice. Before suing, a private plaintiff must serve a Notice of Violation on the alleged violator and on the Attorney General, identifying the product and the chemical. This 60-day notice is the document manufacturers actually receive. Thousands are served every year.
4. Penalties and fees. Civil penalties can run up to a statutory maximum per violation per day, and, decisively, a prevailing private plaintiff recovers attorney fees. The fee recovery is the engine of the model.
5. Settlement is the norm. Most notices resolve in a negotiated settlement that combines a payment, attorney fees, and an agreement to warn or reformulate going forward.

This "bounty-hunter" structure means the practical compliance driver is not a government auditor but the prospect of a 60-day notice from a private firm. It rewards documented, defensible decisions: a manufacturer who can show either a sound exposure assessment below the safe-harbor or an adequate warning in place is in a far stronger position when a notice arrives.

What a manufacturer typically does

A workable program for an electronics manufacturer selling into the US usually combines several of these steps:

• Get a full material declaration from suppliers, ideally a full material disclosure, not only a RoHS or REACH statement, because Prop 65 chemicals overlap but are not identical to either list.
• Cross-check the bill of materials against the current OEHHA list, paying particular attention to cables, cords, grips, plated parts and any soft PVC.
• Decide per exposure pathway: assess exposure against the NSRL or MADL where the analysis is worth it, or apply a safe-harbor warning where it is not.
• Use the safe-harbor wording and symbol, on the product or package and on the product web page, before purchase.
• Pass warning obligations along the chain by contract, since a supplier that provides a part can be required to provide the warning to the next party.
• Keep the file: declarations, list checks, exposure assessments, and the wording used, so a 60-day notice can be answered with evidence.

How Prop 65 fits with the other US and EU chemical rules

It helps to place Prop 65 next to the regimes a manufacturer already knows.

Question	Prop 65	RoHS	REACH
Jurisdiction	California (de facto US)	EU and aligned markets	EU
Legal nature	Warning law	Restriction directive	Restriction and authorisation regulation
Trigger	Exposure above safe-harbor level	Concentration in homogeneous material	Presence, use, or supply of the substance
Compliance options	Warn, or stay below threshold	Stay below threshold only	Remove, reduce, authorise, or notify
Enforced by	Private plaintiffs (mainly)	Market surveillance authorities	ECHA and member-state authorities

The key insight is that the four chemical-content regimes a global electronics maker tracks (Prop 65, RoHS, REACH, and the conflict minerals reporting under Dodd-Frank) all read different parts of the same bill of materials, with different legal logic. RoHS and REACH ask "is the substance present above a limit". Conflict-minerals reporting asks "where did the tin, tantalum, tungsten and gold come from". Prop 65 asks "is a person exposed, and was a warning given". A single material declaration program can feed all of them, but each conclusion has to be reached separately. For an overview of which content regimes attach to a given product, see the REACH and SVHC guide and the glossary entries on RoHS and WEEE.

Common pitfalls

• Treating RoHS compliance as Prop 65 compliance. They cover overlapping but different chemicals and ask different questions. A RoHS-clean cable can still carry DEHP that triggers Prop 65.
• Warning on everything by reflex. Over-warning has itself been challenged as misleading. A warning with no documented basis is a liability, not a shield.
• Using a legacy short-form label after 1 January 2028. Products manufactured and labelled before that date keep the old short form indefinitely, but units manufactured and labelled on or after it must name a chemical under section 25603(b) of Title 27 of the California Code of Regulations.
• Putting the warning only in the manual. The warning must be given before exposure, which for e-commerce means on the product page before purchase, not after the sale.
• Ignoring the supply chain. Cables, power supplies, grips and plated hardware are frequent triggers and are often the parts a brand knows least about.
• Assuming a small company is exempt. The ten-employee threshold is real, but retailers impose Prop 65 by contract regardless of your headcount.
• Quoting an old NSRL or MADL. Safe-harbor levels are revised; always read the current OEHHA table for the specific chemical.

Practical takeaways

For an electronics company entering or already selling in the US market, Proposition 65 is best handled as a standing process, not a one-time label exercise. Build a material declaration program, map your bill of materials against the live OEHHA list, decide warning-versus-assessment per exposure pathway, use the safe-harbor format including the triangle symbol and the p65warnings.ca.gov reference, push obligations down the supply chain by contract, and keep the evidence. Done that way, Prop 65 stops being a recurring 60-day-notice surprise and becomes a documented, defensible part of the same chemical-content discipline you already run for RoHS, REACH and conflict minerals.

See also

• Environmental compliance: what it asks of a product
• NRTL / UL listing: US product safety explained
• PPWR: the EU Packaging and Packaging Waste rules

Working on California Proposition 65 warnings on an electronic product for a real product? AESTECHNO can audit your design and certification plan. Get in touch →

Sources & references

1. Proposition 65 Warnings Website (consumer-facing portal) , California OEHHA www.p65warnings.ca.gov/
2. OEHHA, Office of Environmental Health Hazard Assessment , California OEHHA oehha.ca.gov/proposition-65
3. The Proposition 65 List of chemicals , California OEHHA oehha.ca.gov/proposition-65/proposition-65-list
4. Safe Harbor Levels (NSRLs and MADLs) , California OEHHA oehha.ca.gov/proposition-65/general-info/current-proposition-65-no-significant-risk-levels-nsrls-maximum
5. New Proposition 65 Warnings (clear and reasonable warning regulations) , California OEHHA www.p65warnings.ca.gov/new-proposition-65-warnings
6. Title 27 CCR, Article 6, final regulatory text approved by OAL on 26 November 2024 (sections 25601, 25602, 25603, 25607.2, new 25607.50 to 25607.53) , California OEHHA oehha.ca.gov/sites/default/files/media/2025-01/finalregtext112624approval_0.pdf
7. Final Statement of Reasons, Article 6 Clear and Reasonable Warnings, Safe Harbor Methods and Content (October 2024) , California OEHHA oehha.ca.gov/sites/default/files/media/2025-01/fsor112624approval_0.pdf