LED Testing to EN 62471
Since the 1970s, lasers and LEDs have been classified based on their hazard in the standard IEC 825 (later IEC 60825).
LEDs were incorporated into IEC 62471-1:2005 “Photobiological safety of lamps and lamp systems” in 2005. This standard’s measurement conditions were set at 200 mm with varying fields of view based on risk group. IEC 60825-1 was revised again in 2007, including the removal of most LEDs from being tested under the same standard as lasers.
Since 60825-1(2001) was the last standard to implicitly apply to LEDs, it is often still used to evaluate LEDs because it is the most restrictive due to the possibility of a short measuring distance. Furthermore, other standards and directives, most notably the Electric Toys Standard, still refer to this version of the standard.
Testing to BS EN 62471
The standard for photobiological safety of lamps and lamp systems is BS EN 62471. It is used to evaluate the risk posed by LEDs, LED arrays, lamps, and general lighting sources.
The irradiance and radiance are measured in accordance with the standard, weighted according to the spectral distribution, and compared to the risk group limits of the following hazards:
- Actinic UV
- Blue Light
- Eye IR
- Skin Thermal
- Retinal Thermal
- Retinal Thermal Weak Visual Stimulus
The product would be assigned to risk groups 1-3 or exempt depending on how the radiance / irradiance compares to the limits. The length of time a light source can be safely viewed depends on both the risk group and the wavelength.
Examples of products we have already tested to BS EN 62471 include:
- Medical LEDs
- Phone camera LEDs
- Forensic LEDs
- Night Vision IR illuminators
UKAS Accredited Testing
Lasermet is the UK’s leading test house for testing to the following standards:
- BS/EN 60825-1 / IEC 60825-1
- BS/EN 60825-2 / IEC 60825-2
- BS/EN 60825-12 / IEC 60825-12
- BS/EN 60601-2-22 / IEC 60601-2-22
- 21 CFR 1040.10
- BS/EN 60825-1:2014, 2007, 2001 (off-site)
- BS EN 62471
LED Testing Packages
The full LED Testing package includes the following services:
PROTOTYPE & FINISHED PRODUCT TESTING
We will test and certify your prototype or completed product to the appropriate standard or standards and provide a full test report including details of:
- Measurement test results
- Required Engineering Controls
- Risk group assignment
- Required information in User Manual and Product Brochures
- Required Labelling
- Failure modes of drive electronics and other reasonably foreseeable failures affecting safety
We will issue a classification conditional on making the listed changes (such as labeling, user information, and minor engineering changes) if a product fails to meet the desired classification due to minor failures. When a retest is required, it is usually done at a reduced cost.
CONSULTANCY AT THE DESIGN STAGE
Imagine this scenario:
You work for two years on a product that uses LEDs (or another non-laser light source). Your focus will be on producing an excellent product, and only when you are close to production will you submit your product for LED safety testing, only to discover that changes are required to meet the standard. Changes in the late stages of development can be costly and cause production and sales to be delayed. Significant design changes can be costly both financially and in terms of time.
As a result, to avoid having to make changes to your product in order to meet the safety requirements of BS EN 62471, we recommend that you involve us early in the design process.
CE MARKING, SAFETY STANDARDS, & FDA (CDRH) REPORTS
As part of the process of CE marking, all LED products sold in Europe must be certified to EN 62471.
- Low Voltage Directive
- Machinery Directive
- General Product Safety Directive
- Radio & Telecommunication Transmission Equipment Directive
- Medical Devices Directive
Most manufacturers prefer to have their compliance with the relevant LED safety requirements independently verified.
IManufacturers achieve product conformity in European countries by certifying products to the applicable standards. It is the manufacturer’s responsibility to identify the relevant standards, design the product appropriately, and include a declaration of conformity in the user manual. Non-conformances are detected and addressed by various national enforcement organizations, such as The Trading Standards Organisation in the United Kingdom. The standards are set by expert committees and are constantly reviewed and amended. This places responsibility on manufacturers while also allowing standards to be kept up to date with changing technology, new information, and changes in current practice.
The situation for LED products is different in the United States. In the United States, product safety is governed by Federal Regulations, which are enforced by the Food and Drug Administration (FDA).
LED products are not subject to any Federal Regulation (for example, 21 CFR 1040.10) and are not required to be registered.
INFORMATION REQUIRED FOR LED TESTING TO BS EN 62471
- Intended Risk Group of product
- Wavelengths accessible during normal operation
- Approximate powers accessible during normal operation
- Can the LED(s) fire either continuously, or repeatedly while pulsing
- LED datasheets
- One functioning unit, as close as possible to final version
- Brief description of product, its function, and number of LED sources
- Unit set-up / operating instructions
- Details of pulse structure
- Any additional equipment necessary to operate unit
- Copies of all required LED safety labels
- Copy of product user manual
If some of the information/items requested above are not supplied, it may take a long time to analyze the circuit, resulting in additional test costs. In some cases, classifying the equipment may be impossible without all of the relevant samples/information listed above.
As a result, we strongly advise manufacturers to carefully consider their drive electronics to ensure that the reasonably foreseeable single fault failure requirement is met. Otherwise, serious issues are likely to arise during the testing stage, when manufacturers are under pressure to get the product on the market.