{"id":1422760,"date":"2021-03-19T12:24:29","date_gmt":"2021-03-19T12:24:29","guid":{"rendered":"https:\/\/www.jacksonsart.com\/blog\/?p=1422760"},"modified":"2026-03-31T15:49:46","modified_gmt":"2026-03-31T14:49:46","slug":"explaining-carcinogen-warnings-on-artists-materials","status":"publish","type":"post","link":"https:\/\/www.jacksonsart.com\/blog\/2021\/03\/19\/explaining-carcinogen-warnings-on-artists-materials\/","title":{"rendered":"Prop 65: Explaining Warnings On Artists’ Materials"},"content":{"rendered":"

In California, it is a requirement to label products that contain chemicals that may cause cancer, birth defects, or reproductive harm. Products sold outside of California are not required to have the warning label, even if they contain the same substances.<\/span>
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What Is Proposition 65, and Why Are These Warnings Everywhere?
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Federal vs Californian Law<\/h3>\n

Under federal law, artists\u2019 materials such as oil paints are exempt from the general ban on lead in consumer paints, provided they are clearly labelled and meet ASTM D4236 safety standards. This is why brands which use traditional lead-based whites can still sell their products legally to artists.<\/p>\n

However, while these products may be fully compliant with federal safety regulations, California\u2019s Proposition 65 imposes stricter labelling requirements. Even trace amounts of certain chemicals \u2014 including naturally occurring ones in pigments \u2014 can trigger a mandatory warning if exposure exceeds the state\u2019s very low thresholds. This helps explain why a product may be considered \u2018non-toxic\u2019 under federal standards but still carries a cancer or reproductive harm warning in California.<\/p>\n

Warning Label Requirements<\/h3>\n

Companies often label such products, irrespective of whether they will be sold in California or transported outside of the state. This is why if you live outside of California, you may encounter two different art products containing the same chemicals, but only the one that has been produced in California will have the warning label.<\/p>\n

California\u2019s Proposition 65, also called the Safe Drinking Water and Toxic Enforcement Act, came into law in 1986 and is intended to help people make informed decisions about protecting themselves from chemicals that could cause harm.<\/p>\n

As part of the law, the state is required to publish a list of chemicals that are \u2018known to the State of California to cause cancer or reproductive toxicity.\u2019 The list is updated at least once a year and contains nearly 1000 chemicals. The complete list can be found here on the California Office of Environmental Health Hazard Assessment (OEHHA) website<\/a>. This list ranges from obvious industrial toxins to some naturally occurring minerals.<\/span><\/p>\n

\"Carcinogen<\/a>
Artists’ materials with the Proposition 65 warning aren’t necessarily more hazardous than those without it. Products sold outside of California are not required to have the warning label even if they contain the same substances.<\/figcaption><\/figure>\n

Why Some Products Have Carcinogen Labels and Others Don\u2019t<\/h3>\n

As part of the law, most manufacturers selling products in California must provide \u2018clear and reasonable warnings\u2019, unless the expected level of exposure would pose no significant cancer risk. Businesses decide whether to put warning labels on their products based on their knowledge of the types of chemicals in them.<\/p>\n

Products that are sold outside of California are not required to have the warning label, even if they contain substances that might cause cancer. Some companies that sell products all over the world might only label those sent to California, even though all their products contain the same compounds.<\/p>\n

Why Do So Many Products Have Prop 65 Warnings?<\/b>\u00a0<\/span><\/h3>\n

California\u2019s standards for requiring a warning are very strict. The threshold for many chemicals is extremely low (often far below what federal safety regulations consider dangerous).<\/span><\/p>\n

Many businesses choose to label out of caution, even if the actual risk is minimal. This is because failing to warn when required can lead to costly penalties (up to $2,500 per day per violation!)\u200b<\/span><\/p>\n

As a result, Californians see Prop 65 warnings on a wide variety of items \u2013 electronics, jewellery, foods (like coffee or canned goods), furniture, and art and craft materials, among many others.<\/span><\/p>\n

Why Do So Many Art Supplies Have This Warning?<\/b><\/h4>\n

If you\u2019re an artist or hobbyist, you\u2019ve probably noticed harm warnings on paints, pigments, clays, and other art supplies. Artists\u2019 materials often carry Prop 65 warnings because of certain things in them. For example, heavy metals in pigments, solvents in painting mediums, or other chemicals used in art products. Many mineral pigments (like Cadmium Reds, Cobalt Blues, or earth colours) naturally contain trace amounts of metals that are on the Prop 65 list.<\/span><\/p>\n

The law makes <\/span>no exception<\/span> for \u2018naturally occurring\u2019 versus added chemicals \u2013 if using the paint could expose you above the limit, it needs a warning. Even tiny trace levels of a listed chemical can trigger a Prop 65 warning label.<\/span><\/p>\n

For<\/span> example<\/span>, <\/span><\/i>Golden<\/a> explained why its Zinc White oil paint carries a warning for cadmium and lead: the zinc oxide pigment is mined from the earth and contains extremely low impurities of lead and cadmium (under 12.5 ppm cadmium and 2.5 ppm lead).\u00a0<\/span><\/p>\n

These levels are so low that toxicologists consider them insignificant under federal art material safety standards. In fact, ingesting a pea-sized amount of that paint would only expose you to about the same amount of lead and cadmium as what\u2019s allowed in a day\u2019s worth of drinking water\u200b.<\/span><\/p>\n

The product is considered safe to use and meets all national art product safety guidelines, but because those metals are present even in trace amounts, California requires the warning\u200b.<\/span><\/p>\n

This illustrates a common situation. The warning doesn\u2019t automatically mean the art supply will harm you, only that it contains a chemical that, in high enough exposure, could be a concern. Often, the chemicals are bound up in the product (like metals in solid pigment) and only pose a risk if the product is mishandled (e.g. sanding or spraying without ventilation, or ingestion).<\/span><\/p>\n

The bottom line for artists:<\/b><\/span><\/h3>\n

Don\u2019t panic when you see a Prop 65 warning on your art supplies. The label is there because California errs on the side of caution. Even natural ingredients (earth pigments, minerals, etc.) can contain known trace carcinogens or toxins\u200b.<\/span><\/p>\n

It doesn\u2019t necessarily mean the product is \u2018toxic\u2019 in normal use. Use it responsibly (avoid creating dust or fumes, don\u2019t ingest it, etc.), and you can continue to create art safely.<\/span><\/p>\n

\"Carcinogen<\/a>
The Prop 65 warning regulations got an update effective <\/span>January 1, 2025, with some important changes to how warnings must be given. These changes were aimed at making warnings more informative for consumers.<\/span><\/figcaption><\/figure>\n


\nProp 65 Requirements in 2025: What\u2019s New?<\/b><\/h2>\n
Short-Form Warnings Now Name the Chemical<\/b><\/h5>\n

In the past, the short-form warning didn\u2019t have to list a specific chemical (it could just say \u2018Cancer\u2019 or \u2018Reproductive Harm\u2019). Under the 2025 amendments, any short-form warning on a product must include the name of at least one chemical that triggers the warning\u200b.<\/span><\/p>\n

It also must indicate the type of hazard. For example, a new short-form might say \u2018Cancer risk from exposure to Lead\u2019 or \u2018Can expose you to Toluene, a reproductive toxicant\u2019, instead of the old generic statement\u200b.<\/span>
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\u2018CA WARNING\u2019 Language Option<\/b><\/h5>\n

The traditional wording still starts with \u2018WARNING:\u2019, but businesses now have the option to use \u2018CA WARNING\u2019 or \u2018CALIFORNIA WARNING\u2019 instead. So don\u2019t be surprised if you see \u2018CA WARNING:\u2019 on some labels \u2013 it\u2019s legally equivalent to \u2018WARNING\u2019 in this context. The text still needs to be in bold and all caps to grab attention\u200b.<\/span><\/p>\n

Triangle Symbol Still Required (except for foods)<\/b><\/h5>\n

The ⚠️ triangle icon continues to be a required element for most Prop 65 warnings\u200b. You\u2019ll still see it on product labels next to \u2018WARNING\u2019.<\/span><\/p>\n

One notable exception is with food product labels: for food items, the new regulation allows short-form warnings without the triangle symbol\u200b. For non-food consumer products, assume the triangle will be there.<\/span><\/p>\n

Internet Sales \u2013 New Clarity<\/b><\/h5>\n

If you\u2019re shopping online, the seller must provide the Prop 65 warning on the website before you complete the purchase, typically on the product page or at checkout\u200b.\u00a0<\/span><\/p>\n

The 2025 update clarified that for online purchases, a business can comply by giving an electronic\/website warning and doesn\u2019t have to also include a physical warning on the product package when it\u2019s delivered\u200b. Many companies still do put it on the package, but legally the online warning covers the requirement for that sale\u200b.<\/span><\/p>\n

Other Labelling Changes<\/b><\/h5>\n

The new rules removed some old font-size requirements that tied the warning font to other text on the package. Now, the main rule is that the warning text (short or long form) must be at least 6-point font and prominent enough to be noticed\u200b<\/span>.<\/p>\n

Additionally, there are now specific tailored warnings for certain products (like vehicle parts, furniture, etc.) However, for most consumer goods, including art materials, it\u2019s the standard warning that applies\u200b.<\/span><\/p>\n

Transition Period Until 2028<\/b><\/h5>\n

Don\u2019t worry if you still see the \u2018old\u2019 style short-form warnings (the ones that just say \u2018Cancer\/Reproductive Harm \u2013 www.P65Warnings.ca.gov\u2019) on some products. Businesses have a grace period to adjust: products made before Jan 1, 2028 can use either the old or new warning language and still be considered compliant\u200b.\u00a0<\/span><\/p>\n

This means that through 2027, companies can phase in the new labels. By January 2028, any short-form warnings should be using the new format with the chemical name\u200b. So during 2025\u20132027, you\u2019ll likely encounter a mix of warning styles on store shelves. Both are legally valid for now. The difference is just that the newer ones give you more specifics.<\/span><\/p>\n

\"ACMI<\/a>
ACMI-certified product seals indicate when products have been evaluated by a qualified toxicologist and are labelled in accordance with federal and state laws in the USA.<\/figcaption><\/figure>\n

How to Get More Information About What\u2019s in The Product<\/h2>\n

While manufacturers are required to put Prop 65 warning labels on applicable products sold in California, they are not required to report those details to OEHHA (the Office of Environmental Health Hazard Assessment). As a result, OEHHA cannot provide product-specific information to help consumers understand which chemical is present or the potential risk it poses.<\/span><\/p>\n

Since August 30, 2018, Prop 65 long-form warnings must name at least one listed chemical and indicate whether it can cause cancer, reproductive harm, or both. Manufacturers aren\u2019t required to list every chemical present, but the warning must be clear, reasonable, and include a reference to<\/span> www.P65Warnings.ca.gov<\/span><\/a>.<\/span><\/p>\n

Short-form warnings, often used on small packaging or where space is limited, originally didn\u2019t need to name any chemical. However, this is changing. From January 1, 2025, all newly manufactured products using short-form warnings must also name at least one chemical of concern. Businesses have until January 1, 2028, to fully comply with this updated requirement.<\/span><\/p>\n

If you find a carcinogen warning label on a product and want more information:<\/p>\n