INDIA’S SAR LIMITS SHOULD CHANGE – HERE’S WHY

By Michael Milligan

Not many people get excited about a mobile phone’s Specific Absorption Rate (SAR). But mention radio frequency (RF) exposure, and that will soon change. Yet the relationship between the two is not well known outside of the industry. The SAR is the measure of the amount of RF energy absorbed within the body. The SAR limits for devices are well established and based on a robust body of scientific knowledge. Compliance with the limits is an essential requirement in many countries worldwide, including India.

Most of the world has adopted the recommendations of the International Commission on Non-Ionizing Radiation Protection (ICNIRP), a body recognized for its expertise by the World Health Organization (WHO). ICNIRP’s recommended SAR limit of 2 watts per kilogram over a 10-gram mass (‘2W limit’) has been adopted into national regulations and standards in more than 158 countries around the world – but not India.

While most countries have followed ICNIRP’s recommendations since 1998, a handful have gone with the limits used by the United States Federal Communications Commission (FCC), which were adopted in 1996. The FCC limit for mobile phones is 1.6 W/kg over a 1 gram mass (‘1.6W limit’) and has been traditionally used by countries that have used similar frequency bands as the US – although the SAR limits have little to do with the operating frequencies. So, the globe has generally been in either of two camps – the vast majority adopting ICNIRP’s 2W limit or the FCC’s 1.6W limit.

Yet in 2012, India adopted the US FCC limit even though its frequency allocations would typically align it with ICNIRP. This created a hybrid approach that does very little for anyone – except make it harder for India’s device manufacturers, who must design and test devices against the 1.6W limit while competitors marketing outside of India design and test against the 2W limit.

One of the first questions that is often asked about the two limits is whether one is safer than the other. The answer to that is no. There is no health difference between the two limit values – since both values are far below the levels known to cause harm. The difference between the actual level of harm and the limit devices must comply with is known as ‘reduction factors’. These reduction factors allow for different populations such as the sick, elderly, children, and pregnant women to all be protected, and they are just one of the elements incorporated into the standards to ensure suitable protection. As ICNIRP has said: “There are a number of steps involved in deriving ICNIRP’s guidelines. ICNIRP adopts a conservative approach to each of these steps in order to ensure that its limits would remain protective even if exceeded by a substantial margin. For example, the choice of adverse health effects, presumed exposure scenarios, application of reduction factors and derivation of reference levels are all conducted conservatively. The degree of protection in the exposure levels is thus greater than may be suggested by considering only the reduction factors, which represent only one conservative element of the guidelines. There is no evidence that additional precautionary measures will result in a benefit to the health of the population.”

Since the ICNIRP recommended limits are considered protective for all – what is the difference between them and the FCC limits? Well, as indicated above, the limits are based on a substantial body of scientific research, and in the case of ICNIRPs, the scientific basis of the recommendations was last updated in 2020. This followed a seven-year process of review, consultation, and scientific evaluation.

Therefore, the ICNIRP (2020) recommendations represent the latest in scientific knowledge. The 2020 guidelines introduced some changes, particularly above 6 GHz for 5G technologies that were not in the previous 1998 guidelines, and this shows how the guidelines have evolved based on increased knowledge and the latest research.

In contrast, the FCC limits were adopted in 1996 and are based on the ANSI/IEEE C95.1-1992 standard and the NCRP’s 1986 report on the Biological Effects of RF Fields. The FCC has not updated them since then, so the scientific basis and rationale of the FCC limits are now 30 years old.

Although the IEEE C95.1 standard has been updated twice since the FCC adopted its limits – once in 2005 and again in 2019 – the FCC has not acted to revise its limits to reflect the updated science. As a result, even though the IEEE standard now has largely harmonized its recommendations with those of ICNIRP – to the point that both now recommend a 2W/kg SAR limit – the FCC’s limits continued to reflect the old standards rather than the latest science.

As was noted in the IEEE C95.1-2005 standard, “Since publication of ANSI C95.1-1982, significant advances have been made in our knowledge of the biological effects of exposure to RF energy ICES agrees that the biologically based ICNIRP rationale is more appropriate than the purely dosimetry-based rationale in ANSI C95.1-1982 and IEEE Std C95.1-1999.”

That really highlights the difference between the FCC and ICNIRP/IEEE approaches—the latter is based on biological effects (which seems more appropriate for a standard designed to protect us), while the FCC’s limits were based on limitations in measurement—or dosimetry—which the IEEE revised.

One might argue that there is not much difference between 1.6W/kg and 2W/kg of power absorption, but it is really in the measuring mass (the 1gm vs 10gm) that things become difficult. The FCC’s smaller averaging mass makes design and testing more difficult, while ICNIRP’s measuring mass is actually based on biology—a fact that makes it inherently more suitable for human exposure limits, i.e., the 10-gram average correlates with local temperature rise much better than the 1-gram average.

In 2012, when India adopted the 1.6W limit, it was not at all clear why the decision was made, but the telecom market in India has changed dramatically since then. The industry had very little in the way of manufacturing and was importing the devices that it was selling. Now, 97% of the devices sold within the country each year are manufactured in India, and the industry is exporting 25% of its manufacturing output worth $10 Billion, making it the second largest device manufacturing country in the world – with enormous potential still before it.

With this growth, the government has an opportunity to reconsider the SAR limit that devices must be tested against. In fact, sticking with SAR limits that are scientifically outdated and that are at odds with the markets that India is, or is planning to, export to could pose a potential roadblock to achieving the overall aims of the Government’s policies and plans for the industry.

As we have already seen, the current limit does not offer any health benefits, but it certainly complicates compliance testing, adding additional time and cost, which in turn makes devices more expensive. Addressing this issue will make India’s device manufacturers even more competitive and will only further encourage the industry’s success.

About the Author:

Michael Milligan is the Secretary General of Mobile & Wireless Forum (MWF). The MWF is an international association of companies with an interest in mobile and wireless communications including the evolution to 5G and the Internet of Things.