What is SAR Testing for Absorption Ratio

SAR stands for Specific Absorption Rate. Simply put, it measures the amount of electromagnetic radiation emitted by electronic devices that is absorbed by the human body. Its core purpose is to protect human health and prevent harm from excessive electromagnetic radiation.

Currently, the European Union, the United States, Canada, and other countries/regions mandate sar testing for electronic devices with wireless functions. Products without a qualified report are directly prohibited from being placed on the market

Many people mistakenly believe that only mobile phones and headsets require sar testing—this is completely wrong!

Any device with wireless functions (Bluetooth, WiFi, 5G, NFC, etc.) must undergo SAR testing, including portable energy storage power supplies, smart wearables, and automotive equipment.

In particular, many portable energy storage power supplies now feature Bluetooth control, so SAR testing must not be overlooked

Core Standards & Applicable Products for SAR Testing

SAR testing does not follow a unified standard; requirements vary by country/region. It is mainly divided into two major systems: the EU and the US, with reference to relevant domestic standards. Accurate compliance prevents pitfalls��

European Region (Required with CE certification)

• Core Standards: EN 50361 (General Standard), EN 62209-1 (Specific Test Method)

• Compliance: Must meet the eu red directive; it is a mandatory extended test item for CE certification.

• Limit Requirement: Head/body absorption dose ≤ 2.0 W/kg (based on 10g tissue), strictly following EU electromagnetic radiation regulations, consistent with limits for mobile phones, kids’ watches, etc.

• Applicable Products: Portable energy storage power supplies, smart speakers, wearable devices, automotive electronics with Bluetooth, WiFi, 4G/5G functions.

A SAR test report paired with CE-RED certification is mandatory for customs clearance when exporting to the EU.

United States (Required with fcc Certification)

• Core Standards: FCC OET Bulletin 65C, IEEE 1528

• Compliance: Must meet fcc part 15 / Part 22; a mandatory threshold for market entry in the US.

• Limit Requirement: Head absorption dose ≤ 1.6 W/kg (based on 1g tissue), stricter than the EU with more detailed test procedures, focusing on radiation emission control.

• Applicable Products: All electronic devices with wireless transmission, including portable energy storage power supplies (Bluetooth/WiFi control), mobile phones, tablets, wireless headsets, etc.

SAR reports are required for random inspections on Amazon US.

China & Other Regions (Supplementary as Needed)

• China Standard: GB 21288-2017, limit consistent with the EU (≤ 2.0 W/kg).

Mainly for domestic sales and 3c certification. After portable energy storage power supplies are included in China’s 3C certification, SAR testing may be required in some scenarios.

• Other Regions:

• Canada (IC standards)

• Australia (ACMA standards)

Limits refer to the US/EU; test procedures are generally reusable without repeated testing—only a regionally recognized report is needed.

Key Reminder:

Products without wireless functions (e.g., ordinary non-Bluetooth portable power supplies, purely wired electronic devices) do NOT need SAR testing—do not waste money on unnecessary tests.

However, any product with a wireless module, even low-power Bluetooth, must be tested. Random inspections by EU/US customs will verify this.

How is SAR Testing Performed?

Use a qualified third-party laboratory (must hold ISO 17025 accreditation, e.g., JJR LAB, for reports to be accepted by customs and platforms). The process is straightforward��

 Pre-Consultation & Document Preparation (1 day)

Provide the laboratory with 3 core details:

• Product type (e.g., portable energy storage power supply)

• Wireless functions (Bluetooth/WiFi/5G)

• Target market (EU/US/Domestic)

Prepare documents:

• Product circuit diagram

• Wireless module parameters

• Bilingual product manual (Chinese & English)

• 2–3 samples (identical to mass production; wireless modules unmodified)

Additional descriptions required for special functions.

 Scheme Confirmation & Agreement Signing (1 day)

• Laboratory develops a test plan based on product parameters, specifying standards, items, timeline, and cost.

• Review and sign the entrustment agreement, clarifying responsibilities, accuracy, and report format (digital/printed).

Confirm the report meets customs/platform requirements for the target market to avoid disputes.

 Sample Shipment & Laboratory Acceptance (1–2 days)

• Ship samples with proper protection to avoid damage to samples or wireless modules.

• Laboratory verifies sample information and wireless functionality before testing.

Non-compliant or faulty samples will require resupply, delaying the timeline.

Laboratory Testing & Rectification (5–7 working days)

• The laboratory uses a professional test system to simulate human contact (handheld, close to body) and measures absorbed electromagnetic radiation during normal operation, with full data recording in accordance with standards.

• If results are non-compliant (e.g., excessive radiation), the laboratory provides rectification suggestions:

￮ Optimize wireless module placement

￮ Reduce transmission power

￮ Add shielding layers

Resample and retest after rectification until compliance.

Pre-testing is recommended to reduce retest costs.

Report Issuance & Follow-Up Maintenance (1 day)

• Upon passing, a bilingual SAR test report (Chinese & English) with an accredited official seal is issued, listing standards, limits, and test data for full traceability.

• Store the report securely for random inspections by customs, Amazon, etc.

Retesting is required if wireless modules or appearance are modified to avoid invalidation.

Critical Pitfalls for Newcomers

a. Mistakenly testing products without wireless functions

Only products with Bluetooth, WiFi, etc., need testing; wired products do not.

b. Confusing EU and US standards

EU: ≤ 2.0 W/kg (10g tissue); US: ≤ 1.6 W/kg (1g tissue).

Wrong standards = invalid reports, rejected by customs.

c. Using unaccredited laboratories

Reports from labs without ISO 17025 or regional recognition are invalid.

Choose reputable labs such as JJR LAB to avoid wasted cost and delayed clearance.

d. Samples inconsistent with mass production

Modified wireless modules or transmission power invalidate reports.

Products will be removed from shelves during platform inspections, consistent with all cross-border compliance rules.

e. Missing SAR testing

Wireless products exported to the EU/US without SAR testing risk:

• Customs seizure

• Amazon listing removal

• Fines from FCC / CPSC

Additional SAR Testing Information

Testing Timeline:

Regular: 5–7 working days;

Expedited: 3–4 days (extra fee);

Complex products (multiple wireless modules): +1–2 days.

Cost Reference:

• Single wireless function (e.g., Bluetooth): USD 1100–1750

• Multiple wireless functions (Bluetooth + WiFi): USD 2200–4200

Charged by function count and target market; domestic testing is relatively lower.

Application Scenarios:

Customs clearance in EU, US, Canada;

Listing on Amazon, independent websites, offline retailers;

Support for China 3C certification.

Avoidance Tips:

Prioritize labs offering one-stop services: pre-test + rectification + report.

Ideal for first-time SAR testing sellers to minimize detours.