← All interactive lessons · About 4 minutes · Expand each chapter · No audio
Correction: The earlier universal gap and safe/unsafe slider conflated different assessment frameworks. They have been removed.
1. Identify the document
Record the issuing body, edition, jurisdiction and intended application. A regulatory limit, scientific guideline and voluntary precautionary recommendation have different roles. A lower recommendation is not automatically a demonstrated threshold of harm.
2. Match the quantities
Check frequency, units, population, averaging time and measurement location. RF power density, low-frequency magnetic fields and SAR cannot be compared as though they were one quantity.
3. Read beyond a single number
ICNIRP’s 2020 RF guidance covers 100 kHz to 300 GHz and includes exposure limits with dosimetry and health-evidence appendices. Use the conditions in the original document. This lesson does not certify a room against any standard.
4. Ask an answerable question
Instead of asking which number looks smallest, ask whether the measurement method and exposure situation match the chosen document. For a formal assessment, use an appropriately qualified professional and the applicable local requirements.
Check your understanding
Can two different limits be divided to produce a universal health-risk multiplier?
Reveal the answer
No. A numerical ratio does not establish a ratio of health risk, especially when the assessment conditions differ.
Further reading
ICNIRP RF guidelines explain technical assessment conditions. Reading a shielding report explains why test conditions matter.
Editorial update: 17 October 2026. Educational explanation, not a personal exposure or medical assessment.