IEC TC 76 guides laser safety standards to worldwide acceptance

50 years old this year, lasers cross many
areas of manufacturing

By Jeanne Erdmann

Lasers have become so integrated into our lives that we hardly notice them anymore. Perhaps a 50th anniversary of the first laser calls for a few moments' reflection. Thanks to lasers, we can listen to music and watch a movie without a care. We can stand at a podium and point a focused beam of light at a PowerPoint presentation, careful, of course, not to direct the light into someone’s eye. Laser pointers are also used to send sniffer dogs to inspect particular containers. One of the most remarkable uses for lasers is in medicine. Lasers can demolish a tumour without surgery, correct vision, heal wounds, even remove unwanted hair.

Use of lasers is broadening

Lasers are looking pretty fresh-faced, considering they’re 50 years old. Lasers have found a home too in so many areas of human and veterinary medicine. Underlying the success of lasers are IEC standards that address critical issues such as safety and measurement. In the critical area of brain surgery, lasers help create maps of the brain through CT (computed tomography) and MRI (magnetic resonance imaging). These direct surgeons to exactly where they need to operate. Thanks to IEC 62464-1, Magnetic resonance equipment for medical imaging - Part 1: Determination of essential image quality parameters, no one has to give a thought to image quality and measurement issues.

"In times of economic slowdown, to see the committee growing is a positive sign," says William Ertle, president of Rockwell Laser Industries and, since 1978, Secretary of IEC TC (Technical Committee) 76: Optical radiation safety and laser equipment. TC 76 writes standards for laser radiation pertaining to human safety, which includes lasers and LEDs (light-emitting diodes). TC 76 now has 90 members from 20 P- (Participating) Member countries and 16 O- (Observer) Member countries. Membership has grown by approximately one-third in the past 10 years. Because of the diversity and number of applications, standards written by TC 76 are popular among IEC publications.

Lasers cross many areas of manufacturing, such as free-space optical communications, lighting and medical technologies. Also, LEDs are increasingly used in streetlamps and home illumination. "For the size, niche, and participation we are one of the most relied-upon Technical Committees and we produce quite a few standards," says Ertle. The two TC 76 standards most relevant to the worldwide community are IEC 60825-1, Safety of laser products - Part 1: Equipment classification and requirements, the main standard for manufacturing, and IEC/TR 60825-14, Safety of laser products - Part 14: A user's guide.

"Our committee is a safety committee and we write safety standards," says TC 76 Chairman Jerome Dennis, who has watched the industrial laser market grow exponentially in the past decades. Dennis has 55 years of primary optical radiation technology experience. He began his career as a Navy physicist working on optical flash effects of nuclear weapons. When the laser age began in 1961, Dennis jumped onboard. Since then, he’s worked for both industry and government, and is now consulting after finishing his career at the CDRH (Center for Devices and Radiological Health) – a branch of the US (United States) FDA (Food and Drug Administration) – and the FDA itself.

In the nearly 12 years that Dennis has chaired TC 76, committee members have refined their basic standard, have written new standards and revised others. TC 76 has also adopted joint IEC photobiological safety standards for lamps and lamp systems. One of the most recent changes was removing LEDs from most laser standards, including free-space optical communications equipment. In the majority of applications, LEDs function more like lamps. Most applications treat LEDs as lamps. However, when used in fiber optic communication systems, LEDs resemble small sources, so their hazards are more similar to lasers than to lamps.

The success of IEC TC 76 standards has prompted organizations in countries such as the US to adopt IEC standards. For instance, the CDRH enforces a safety standard for laser products sold or imported into the US. The CDRH has not been able to keep pace with the ongoing refinement of the IEC international Standards and is therefore taking steps to align its safety requirements with the IEC, says Ertle. The US is becoming more and more interested in IEC standards to the point where the CDRH will accept certain sections of an IEC publication. "It’s basically our government saluting that standard saying in these areas we’re going to accept the IEC standards," says Ertle.

The US acceptance of TC 76 standards adds to the TC’s growing worldwide influence. Canada now has a presence in TC 76, and China hosted the 2008 TC 76 meeting, a first for that Asian country.

Today, TC 76 expects to remain busy, especially with LEDs finding more and more applications. For example, in some applications, a certain amount of light is needed to get the job done. With a traffic light, a person in a car or on the street, wouldn’t be exposed to hazard, but a workman servicing the fixture could be exposed depending on how bright the light is or whether it’s on or off.

IEC TC 76 is also working on documents for measurements, fiber optics and medical applications. Also covered under TC 76 standards are intense pulse light systems, which are technically not lasers but very bright broadband lights that have caused many injuries. Since TC 76 is responsible for optical radiation safety, these lights fall under its scope.

Growth brings challenges

The growth of laser technology is presenting new challenges to TC 76. "So many other technical committees are establishing standards for the performance of light-generating products, we need to liaise with them to make sure that we’re speaking the same language and we understand where our diverse committees are coming from," comments Dennis.

Those opportunities will come because TC 76 has been invited to the IEC General Meetings in October 2010 in Seattle, Washington, US, and in Melbourne, Australia, in 2011. "It’s a big rarity for a niche industry but maybe it’s sign of the time with lots going on in the laser industry," says Ertle.

"We’ll see what happens in 2012," says Dennis.