Belt clips live on in smartphone radiation testing

Most handset makers assume you're using something that separates the phone from your body

A cellphone holster holding an Apple iPhone 5s.

A cellphone holster holding an Apple iPhone 5s.

The FCC's radiation standards for your smartphone date back to the 1990s. But that's OK. You use a belt clip, don't you?

That hallmark of turn-of-the-century tech fashion is largely forgotten these days. That is, until you look at product manuals for some of the newest smartphones on the market. In the fine print about safety, Samsung, Motorola, HTC and LG all talk about accessories that keep a handset at least 1 centimeter away from your body, as if malls were still full of kiosks selling these things to Abercrombie-clad teens.

That fine print became an issue earlier this year in Berkeley, California, when the city government passed a law that would require stores to direct their customers' attention to the radiation-risk language in cellphone user manuals. Like other proposed laws about phone radiation, it's come under legal fire from the mobile industry.

The U.S. Federal Communications Commission says there's no scientific evidence that RF (radiofrequency) radiation from mobile phones causes cancer, headaches, dizziness or other health effects that some critics say are linked to the devices. But it does define how much radiation a smartphone is allowed to emit, using guidelines adopted in 1996. The FCC's rules for testing those emissions likewise harken back to the age of the rave party, though the agency has begun looking into changes.

Manufacturers have to conduct two tests to measure how much RF energy a test dummy absorbs from each phone. One of the tests simulates talking on the phone, with the handset right up against the dummy's head. The other is intended to show how much radiation a body would get just from carrying the device. That's where things get a little weird.

The FCC lets manufacturers decide how far from the dummy their phones are tested.

They have a choice of two standards, according to an information page on the FCC's website. One is for devices "designed to operate on the body of users using lanyards or straps, or without requiring additional body-worn accessories." Those devices need to have a "test separation distance" of no more than 5 millimeters from the dummy.

The other standard is designed to account for accessories that keep the phone away from the user's body. It allows for a test separation distance of as much as 2.5 centimeters, though it lets vendors go closer if they want. "This distance is determined by the handset manufacturer, according to the typical body-worn accessories users may acquire at the time of equipment certification," the FCC page says.

"May" is the key word in that sentence. Sure, people can still buy a holster or a belt clip for a brand-new smartphone. But will they?

"That does not reflect reality today for the vast majority," said analyst Avi Greengart of Current Analysis.

You might expect phone makers to use the closer standard, given how many people carry their phones in their pocket. Vendors know this: They put a lot more effort into slim designs and scratch-resistant glass than into, say, Kid Rock and Spice Girls ringtones. Yet when it comes to radiation testing, they're still stuck in the last decade.

Take the Health and Safety Warranty Guide for the Samsung Galaxy S6 Edge, for example.

"For body-worn operation, this device has been tested and meets FCC RF exposure guidelines when used with an accessory that contains no metal and that positions the mobile device a minimum of 1.5 cm from the body. Use of other accessories may not ensure compliance with FCC RF exposure guidelines," the guide says.

Samsung doesn't say what kind of accessory it's talking about here, but unless it counts purses and backpacks as accessories, the implication is clear: Holster up like a cable guy.

Or check out the safety page from the Motorola Moto G manual: "When using the mobile phone next to your body (other than in your hand or against your head), maintain a distance of 1.5cm (3/4 inch) from your body to be consistent with how the mobile phone is tested for compliance with RF exposure requirements." If you use a case or holder, make sure it doesn't have any metal, Motorola adds.

The user guide for an LG G4 says the phone was tested for "typical body-worn operations," with 1 cm between the body and the back of the phone. And the manual for the HTC One M9 from Sprint comes right out and invites us on a walk down memory lane: "To ensure that RF exposure levels remain at or below the tested levels, use a belt-clip, holster, or similar accessory" to keep the sleek 2015 smartphone at least 1 cm from your body. They don't say which is best, nor do they recommend the best Bryan Adams albums to load on your Rio.

Apple, on the other hand, is either too realistic or too vain to endorse a fashion that the iPhone helped to kill. It uses the 5mm rule.

The FCC doesn't say a phone tested closer to the body is safer than one tested farther away, and the emissions limit is the same for both. Devices either exceed the allowed radiation level or they don't.

Yet the language in some user manuals implies that separation distance does matter if you're worried about radiation. Under the heading, "Can I minimize my RF exposure?" the LG G4 user guide says, "You can place more distance between your body and the source of the RF, as the exposure level drops off dramatically with distance."

And despite their careful advisories about maintaining a buffer between the phone and your body, and making sure the accessory you use doesn't contain any metal that might conduct radiation, cellphone makers don't offer many products to keep their handsets at a safe distance. Most carriers, too, stock just a handful of models. There are better selections at online retailers, especially, which must have more warehouse space for storing unsold belt clips.

So why do manufacturers keep testing phones as if everyone snaps up a matching holster and shows it off on MySpace as soon as they buy a phone?

"Compliance and safety are not the same thing, and compliance with a 5mm testing standard would not necessarily be safer for consumers than compliance with a 1.5cm standard," Motorola Mobility spokesman William Moss said via email. "The test at 1.5cm meets all requirements for consumer safety, and is widely used in the industry." Other major manufacturers did not comment.

Vendors may keep doing it the same way for consistency, said Roger Entner, an independent mobile industry analyst. If anyone took phone makers to court over the safety of their products, they'd have one less thing to explain.

"There's nothing nefarious about testing it the way you've always tested it," Entner said.

"It may be that they started using this as a crutch," Greengart at Current Analysis said. Today's phones are more efficient and therefore emit less radiation, so more of them might pass without the extra buffer, he said. "So maybe it's time for us to update the testing specs."

Stephen Lawson covers mobile, storage and networking technologies for The IDG News Service. Follow Stephen on Twitter at @sdlawsonmedia. Stephen's e-mail address is

Join the newsletter!


Sign up to gain exclusive access to email subscriptions, event invitations, competitions, giveaways, and much more.

Membership is free, and your security and privacy remain protected. View our privacy policy before signing up.

Error: Please check your email address.

Tags mobilesmartphonesregulationApplehtcconsumer electronicsU.S. Federal Communications CommissionSamsung ElectronicsLG ElectronicsMotorola Mobility

Keep up with the latest tech news, reviews and previews by subscribing to the Good Gear Guide newsletter.

Stephen Lawson

IDG News Service
Show Comments

Cool Tech

Bang and Olufsen Beosound Stage - Dolby Atmos Soundbar

Learn more >

Toys for Boys

Nakamichi Delta 100 3-Way Hi Fi Speaker System

Learn more >

Sony WF-1000XM3 Wireless Noise Cancelling Headphones

Learn more >

ASUS ROG, ACRONYM partner for Special Edition Zephyrus G14

Learn more >

Family Friendly

Philips Sonicare Diamond Clean 9000 Toothbrush

Learn more >

Mario Kart Live: Home Circuit for Nintendo Switch

Learn more >

Stocking Stuffer

Teac 7 inch Swivel Screen Portable DVD Player

Learn more >

SunnyBunny Snowflakes 20 LED Solar Powered Fairy String

Learn more >

Christmas Gift Guide

Click for more ›

Most Popular Reviews

Latest Articles


PCW Evaluation Team

Tom Pope

Dynabook Portégé X30L-G

Ultimately this laptop has achieved everything I would hope for in a laptop for work, while fitting that into a form factor and weight that is remarkable.

Tom Sellers


This smart laptop was enjoyable to use and great to work on – creating content was super simple.

Lolita Wang


It really doesn’t get more “gaming laptop” than this.

Jack Jeffries


As the Maserati or BMW of laptops, it would fit perfectly in the hands of a professional needing firepower under the hood, sophistication and class on the surface, and gaming prowess (sports mode if you will) in between.

Taylor Carr


The MSI PS63 is an amazing laptop and I would definitely consider buying one in the future.

Christopher Low

Brother RJ-4230B

This small mobile printer is exactly what I need for invoicing and other jobs such as sending fellow tradesman details or step-by-step instructions that I can easily print off from my phone or the Web.

Featured Content

Product Launch Showcase

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?