IARC 2B Classification
The IARC classification preamble and the general remarks both clarify this important point:
This Monograph is focused on the potential for an increased risk of cancer among those exposed to RF radiation, but does not provide a quantitative assessment of any cancer risk, nor does it discuss or evaluate any other potential health effects of RF radiation.
The assessment of health risks is the responsibility of another part of the WHO - the International Electromagnetic Fields (EMF) Project, which was set up in 1996 to assess the scientific evidence of possible adverse health effects from electromagnetic fields and to provide advice to governments around the world.
Following the IARC announcement in early June 2011 the WHO updated its factsheet on electromagnetic fields and public health in mid-June 2011 and while acknowledging the IARC classification have said mobile phones were not known to cause any health problems:
A large number of studies have been performed over the last two decades to assess whether mobile phones pose a potential health risk. To date, no adverse health effects have been established as being caused by mobile phone use.
In addition, the possible link with cancer is not supported by evidence of an increase in the number of brain cancer cases during the rapid increase in mobile phone use globally according to the 2014 World Cancer Report published by IARC:
Time trends in glioma incidence based on Nordic countries and the USA exclude any large increase in incidence attributable to mobile phone use, albeit with reference to a relatively short time from initiation of exposure. No association was observed between mobile phone use and other cancers.