RF Safety Awareness training is useful for RF technicians, RF engineers, installers, system analysts and subcontractors. It’s important to understand why RF safety awareness training and certification is required by OSHA and the FCC.
The Occupational Safety and Health Administration (OSHA) and the Federal Communications Commission (FCC) require telecommunications workers to be certified for RF safety awareness. The FCC has made it clear that RF safety is truly important for all employees who work on or near wireless and broadcast communication sites. Failure to comply can result in personal injury, fines and lawsuits.
The FCC requires that members of the public should be kept safe when they are near wireless antennas. OSHA requires that employees must be provided with safe work environments. This includes workers who enter and work on or near wireless systems. A workplace that exposes employees to RF energy is considered to be a hazardous environment, and workers with potential exposure must be trained. If you own or manage a company that services wireless and other telecommunications sites, OSHA requires that your employees be trained and certified in RF safety awareness.
Periodic Training
Although OSHA and the FCC do not offer specific guidance on how often your team requires training, most experts agree it should be done for all new employees and on an annual basis for existing employees. Record keeping is extremely important. The RF safety awareness training completion certificate should be signed by the trainer and dated, A copy of the signed certificate should be maintained in your human resources training files. RF safety awareness training is not only required, compliance helps to keep your employees safe, prevent injuries and reduces potential liability.
Most electromagnetic energy levels are generally safe, but you should understand how to determine whether dangerous levels exist. Electromagnetic energy is all around us, generally at low levels. Wireless sites that generate this energy include cellular radio, paging systems, public safety systems and business communications systems. Typical wireless communications systems operate in the VHF, UHF and SHF bands. The human body acts in a way similar to an antenna in that it absorbs a certain amount of RF energy. This absorbed energy is the source of potential health concerns related to RF safety.
Body Resonance
The measurement quantity utilized to measure RF energy is absorbed in a human body is the called the specific absorption rate (SAR). It is usually expressed in units of watts per kilogram or milliwatts per kilogram. The human body has resonance that causes more energy to be absorbed in a range of frequencies around 100 MHz. Because if the resonance, RF Safety standards are generally more restrictive for the 30 MHz to 300 MHz frequency range.
Ionizing radiation is electromagnetic energy capable of producing ions (charged atoms) as they pass through matter. Electromagnetic energy at frequencies above those of ultraviolet (UV) light (such as x-rays) is ionizing and can cause permanent biological cell changes. Non-ionizing radiation is electromagnetic energy that does not have enough photons to create ions. In this case, energy is absorbed as heat. These effects are not cumulative are not shown to cause cancer. RF energy at frequencies below UV light is non-ionizing. The primary danger with high levels of RF energy is tissue heating and RF burns. Proper training allows workers to know the signs of over exposure, and more importantly, how to avoid or protect themselves from higher levels of exposure.
The good news is that wireless telecommunications equipment only generates non-ionizing radiation, and at most cellular and other wireless communications sites the energy levels are low enough that tissue heating is not a matter of concern. Ground-level exposure is much less than the exposure at the same height as the antennas and directly in front of the antennas. For cellular rooftop sites, potential exposure approaching or exceeding the safety guidelines is only likely to be encountered close to and directly in front of the antennas while they are transmitting. Broadcast sites such as AM, FM and TV stations can use much higher power levels, up to 1 million watts for certain stations. Although the amount of RF energy workers can be exposed to at these sites depends on a number of factors, workers going to these sites need to take all precautions to ensure RF safety.
Precautions
RF safety means understanding the basics of electromagnetic energy and its potential effect on the human body, as well as practicing common sense. As an example, employers should ensure that employees do not look into an open waveguide that is connected to an energized power source of microwave radiation. Avoiding or minimizing time directly in front of energized wireless antennas is also beneficial. A good RF safety course covers these precautions in detail.
There is also a difference between uncontrolled and controlled exposure. Uncontrolled exposure occurs when the general public or those unaware may be exposed to RF energy and cannot exercise control. Controlled exposure occurs when exposure results from employment and when those involved are fully aware. The occupational control limits are five times higher than the exposure limits for the general population or uncontrolled exposure. This makes a difference because with controlled exposure, there is an expectation of awareness and training, RF safety is about being aware and identifying areas that may be hazardous, using proper signage, providing written guidelines and training employees and site workers.
Multiple Transmitters
RF safety training should also cover how to address sites with multiple transmitters, which are common. Per FCC rules, RF safety compliance at a site with multiple transmitters is a shared responsibility. The FCC’s exposure guidelines constitute exposure limits, not emission limits, so they are relevant only at accessible locations. Access can and should be controlled by appropriate means such as fences, locked doors and raised antennas.
For broadcast sites, a good RF safety course covers the use of personal protection equipment (PPE). This can include RF protection suits, power control, RF safety monitors and standard operating procedures as part of a robust RF safety program. RF safety monitors are particularly critical when climbing a tower or when working near broadcast sites, where workers should always wear RF personal monitors. In other situations, such as wireless communication sites, monitors are not always needed as long as the employees have received proper RF safety training. Employers should also always ensure that they supply employees with the required safety equipment for any job. For example, this includes proper lighting for required work and observations, safety glasses for any jobs that involve flying debris and first aid kits for their teams. It’s important to ensure that is carried out by employees in a safe and healthful manner.
On-site or Online RF Safety Training
Rf safety training is generally available either with the trainer traveling to your office or online. Online training is convenient and affordable and allows the student to take the course when time is available and set at a comfortable pace. One excellent, convenient and affordable on-line RF safety awareness training options is the course offered by Singer Executive Development. More information can be found at: RF Safety Training. If you bring a trainer into the office, the cost per employee will most likely be higher, unless you have a large number of students. In-person training, with the instructor face-to-face with the students, provides abundant opportunity for questions and answers and a deeper relationship with the instructor. Regardless of the delivery method you choose, it’s important to understand that OSHA and the FCC require your site workers to be certified. Employees such as RF technicians, RF engineers, installers, system analysts and subcontractors can all benefit from RF safety awareness training.
This article on RF safety awareness training was written by Andy Singer. This article first appeared in the February 2016 issue of AGL magazine.
RF Safety Awareness Links and Information:
FCC Human Exposure to RF Radiation Fields
FCC OET Bulletin No. 65 – Evaluating Compliance with FCC Guidelines for Human Exposure to RF
29 CFR 1910 – Occupational Safety and Heath Standards
OSHA Safety and Health Regulations for Construction
Singer Executive Development RF & Microwave Training
