Dear Valued Customer,

We are informing you of the California Prop 65 regulations and the need for the warnings you may be seeing on UPB master shipping cartons. UPB manufactures a wide variety of paper-board and plastic cartons and many of them may be sold into California. Prop 65 is a piece of legislation approved by ballot initiative by California voters in November of 1986. Also known as the Safe Drinking Water and Toxic Enforcement Act, the original purpose of the law was to prevent the dumping of toxic chemicals in waterways. This FAQ will provide a general summary of Proposition 65.

What is Proposition 65?  Proposition 65 requires businesses to warn Californians before exposing them to chemicals in the consumer products they buy and use. Proposition 65 requires the State to publish a list of chemicals known to cause cancer, birth defects or other reproductive harm, known as the “Prop 65 List”. The California Office of Environmental Health Hazard Assessment (OEHHA) administers the Proposition 65 program and maintains the Prop 65 List, which is updated at least once annually. The list presently contains about 1,000 chemicals.  

Which chemicals are on the Proposition 65 List? There is a range of naturally occurring and synthetic chemicals on the Prop 65 List. These chemicals include ones you expect, such as lead, asbestos and tobacco smoke, but also chemicals that may come as a surprise, such as aspirin.  Certain chemicals on the list, such as styrene, carbon black and titanium dioxide are commonly found in consumer products. The updated Prop 65 List can be found at:

Are chemicals that may be found in UPB products harmful to the health of my employees and customers? While components used to manufacture various UPB packaging products may contain Proposition 65 listed chemicals, the types and quantities of chemicals are expected to present very little, if any, actual threat to you or your customers.

For example:

  • All black inks, regardless of who the ink maker or printer is, contain carbon black, a Prop 65 listed chemical. The state of California has identified carbon black to cause cancer only when in it’s respirable form, or dry powder form. When UPB applies black ink to a substrate, that ink is cured into a plastic film which binds the carbon black to the substrate making it impossible to inhale it, if the carton is used as intended. Titanium dioxide, a pigment used to create opaque white, is also known to cause cancer, but only in respirable form.

  • Some of our adhesives contain very small amounts (typically less than 1% or 2%) of toluene or other solvents that may be Prop 65 listed. All of these solvents are quite volatile so they dissipate rapidly once applied to the carton. Hence, the actual amount of these solvents in a finished carton are expected to be close to 0%.

  • Benzophenone is a chemical used in UV coatings as a photo-initiator. When UV coating is applied to a substrate it is then subjected to UV lamps to cure the coating. Energy from UV light cleaves the molecules of benzophenone to initiate the reaction required to convert the liquid coating into a solid plastic film. After that molecule of benzophenone has been cleaved it is no longer actually benzophenone, and therefore is technically no longer a Prop 65 listed substance.

These three examples are common types of listed chemicals found components required to manufacture packaging products, regardless of who that manufacturer may be. While the likelihood that these chemicals can cause harm is expected to be essentially nonexistent, it is UPB’s responsibility to inform our customers that these chemicals may, nonetheless, be present in the final product. In reality, the substances may no longer even be present by the time the product is delivered.

What is the warning requirement for businesses? Businesses are required to provide a “clear and reasonable” warning before knowingly and intentionally exposing anyone to a chemical on the Prop 65 List. UPB is responsible for notifying our customers of any listed chemical that is, or may be, present in the packaging products that it produces. UPB may put a warning label on the shipping case label, but will never alter the graphics of the actual product carton without direction, and proof approval, from our customers.

After August 30, 2018, new Prop 65 regulations took effect. These revisions changed the wording of the required warning. For products manufactured after August 30, 2018, the warning must identify one or more chemicals on the Proposition 65 List, must add a symbol (as depicted below but which also may be printed in black and white for packaging or labels that do not contain the color yellow), and the new warning language will be as follows (either the long form or short form warning is okay):

For cancer:

Prop 65 for Cancer.png

For reproductive harm:

Prop 65 for Repro Harm.png

For cancer and reproductive harm:

Prop 65 for Cancer and Repro Harm.png

Where can I get more information on Proposition 65? For general information on the Prop 65 list of chemicals and list of safe harbor levels, you may contact OEHHA's Prop 65 program at (916) 445-6900, or visit: