The U.S. Supreme Court rejected an industry challenge to a Berkeley law requiring cellphone retailers to include information about radiation guidelines with all sales. Photo: Startup Stock Photos

The U.S. Supreme Court has denied a challenge to a Berkeley law requiring cellphone retailers to warn consumers about radiation exposure.

The 2015 “right to know” law will stay in effect in Berkeley.

A wireless communications trade association, CTIA, challenged the law right after it was passed, arguing it violated retailers’ free-speech rights. After federal courts upheld Berkeley’s law, CTIA took its grievances up to the Supreme Court, where justices denied the petition without any explanation Monday.

In a press release Friday, Mayor Jesse Arreguín called the outcome “a victory for our public health and safety.”

The law in question requires all Berkeley cellphone sales and leases to come with a notice referring to federal radio frequency (RF) exposure guidelines.

The notice must say: “If you carry or use your phone in a pants or shirt pocket or tucked into a bra when the phone is ON and connected to a wireless network, you may exceed the federal guidelines for exposure to RF radiation. Refer to the instructions in your phone or user manual for information about how to use your phone safely.”

The Ninth Circuit Court of Appeals determined that the message is a constitutional safety warning that serves to enforce existing federal guidance. Challenging the law, CTIA lawyers argued that the requirement unfairly forces retailers to distribute politically biased information they might disagree with.

Meanwhile, the California Brain Tumor Association and Harvard Law Professor Lawrence Lessig were among those who rallied behind Berkeley during the challenges to the ordinance, Arreguín said. The latter represented Berkeley in the case pro-bono.

Natalie Orenstein reports on housing and homelessness for The Oaklandside. Natalie was a Berkeleyside staff reporter from early 2017 to May 2020. She had previously contributed to the site since 2012,...