01
Purpose
EN 166:2001 is the legacy general performance and marking standard for personal eye protection. For new products/certification, the current main reference is the EN ISO 16321-1:2022+A1:2025 series.
Eye ProtectionTECHNICAL PPE LIBRARY
EN 166
EN 166 Legacy Eye Protection Standard
EN 166:2001 is the legacy general performance and marking standard for personal eye protection. For new products/certification, the current main reference is the EN ISO 16321-1:2022+A1:2025 series.
Product type
Legacy personal eye-protection reference
Field focus
Code + product + conditions of use
TECHNICAL PRODUCT IDENTITY
EN 166
EN 166Legacy reference1Legacy optical classF / B / ALegacy mechanical codeEN ISO 16321-1Current main seriesAlways verify the actual product label, manufacturer technical documentation and conformity markings.
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Typical use
Field identification of existing EN 166-marked products and current-series comparison when selecting new eye/face protection.
03
What to look for?
Read lens/frame codes on existing EN 166 products; for new selection verify the EN ISO 16321 series and manufacturer conformity documentation.
CLASSES & SELECTION LOGIC
Technical classes in this standard
A class code is not a selection decision by itself. Interpret it together with task-specific risk assessment and manufacturer data.
LEGACY
EN 166:2001
Legacy reference still seen on existing/previously certified products. Current series applies to new certification.
CURRENT
EN ISO 16321-1
Current general occupational eye/face protection reference for new products is EN ISO 16321-1:2022+A1:2025.
READ THE PRODUCT LABEL
Code & marking decoder
EN 166Legacy referenceMay appear on legacy products and stock covered by still-valid older certificates.1Legacy optical classExample of optical class in the EN 166 marking system.F / B / ALegacy mechanical codeMechanical-strength codes in the EN 166 marking system.EN ISO 16321-1Current main seriesCurrent general reference for new occupational eye/face protection products.
READ THE PRODUCT IN THE FIELD
Where is the standard marking found?
Location varies by manufacturer and design. These are the first places to check; final verification must use the actual product and manufacturer documentation.
1
EN 166 marking on lens or frame of legacy products
The marking should be legible, durable and match the product.
2
Manufacturer and legacy codes on temple / side arm
The marking should be legible, durable and match the product.
3
EN ISO 16321-1 series markings and conformity documentation on new products
The marking should be legible, durable and match the product.
STANDARD FAMILY
Standards often reviewed together
EN 166:2001Legacy eye-protection reference
EN ISO 16321-1:2022+A1:2025Current general reference for new occupational eye/face protection
EN ISO 16321-2 / -3Relevant parts are considered separately for welding, mesh and special applications
COMMONLY CONFUSED
They are not the same thing
Legacy EN 166 ≠ current standard for new certification
After 11 November 2025 the EN ISO 16321 series applies to new products/renewed certification; existing legacy certificates may remain subject to their validity conditions.
WRONG-SELECTION EXAMPLE
A typical field mistake
Treating open-sided safety spectacles as sufficient for a chemical splash hazard.
Why is this a problem?
Protector type, coverage and declared splash performance must match the task.
Better approach
Verify the protector type and current standard/marking for the actual hazard.
WHERE IN THE FIELD?
Typical applications
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Existing product identification
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New-product selection
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Grinding / particles
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Chemical splash
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Laboratory
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Maintenance
HSE FIELD CHECK
30-second field check
Use for quick pre-checks. It does not replace certification, competent inspection or task-specific risk assessment.
CHECK FOCUS
Is the standard/edition under which the product was certified clearly identified?
CRITICAL MISTAKE
Treating open-sided safety spectacles as sufficient for a chemical splash hazard.
BETTER APPROACH
Verify the protector type and current standard/marking for the actual hazard.
1
Is the standard/edition under which the product was certified clearly identified?
2
Are lens and frame undamaged?
3
Does the protector type match the actual hazard?
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Are markings legible and consistent with manufacturer documentation?
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For new products/certification, has the EN ISO 16321 series been verified?
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