Major Shift in PPE Standards: Will EN ISO 16321-1:2022 + A1:2025 Replace EN 166? The Ultimate Transition Guide for Manufacturers and Buyers

As global industrial safety standards align to facilitate cross-border trade, the regulations governing Personal Protective Equipment (PPE) are undergoing one of the most significant transformations in decades. For over a quarter of a century, EN 166 has been the undisputed bedrock of European occupational eye and face protection standards—whether for safety glasses, face shields, or specialized goggles.

However, this classic standard is officially stepping down. The European Committee for Standardization (CEN) and the International Organization for Standardization (ISO) have introduced the EN ISO 16321 series to unify requirements globally. With the ratification of the crucial amendment, EN ISO 16321-1:2022 + A1:2025, the timeline for complete replacement has become a pressing reality for PPE manufacturers, procurement managers, and global safety professionals.

This deep-dive guide explores whether EN ISO 16321-1:2022 + A1:2025 replaces EN 166, the critical transition timelines, the key technical differences introduced by the 2025 amendment, and how your business can proactively adapt.

1. The Definitive Answer: Yes, EN 166 is Officially Replaced

Yes, EN ISO 16321-1:2022 + A1:2025 will completely replace EN 166.

This change is not a mere localized update. It is a massive harmonization project between European (CEN) and International (ISO) standards bodies. Historically, manufacturers exporting to Europe had to test to EN standards, while those exporting to the Americas or Asia had to align with ANSI or other local frameworks. This led to redundant testing and multiple certifications for a single product.

By adopting the ISO framework under the “EN ISO” banner, Europe has embraced a truly globalized technical standard. Passing EN ISO 16321-1 means a product’s technical data and safety metrics are aligned with international metrics, substantially reducing trade barriers for global supply chains.

Why was the “A1:2025” Amendment Necessary?

When EN ISO 16321-1 was first published in 2022, testing laboratories and manufacturers noticed ambiguities regarding “headform clearance” and “side-protection coverage” when applying the rules to various facial profiles.

To resolve these implementation pain points, Amendment 1 (A1) was officially enacted. The 2025 revision clarifies ergonomics, provides strict geometric definitions for unobstructed fields of vision, and refines the precise boundaries of protection zones. Therefore, when discussing compliance today, EN ISO 16321-1:2022 + A1:2025 is the singular, definitive benchmark.

2. The Timeline: How Long Are Existing EN 166 Certificates Valid?

The transition from EN 166 to the new harmonized standard follows a phased implementation period designed to prevent immediate market disruption for both CE (EU) and UKCA (UK) markings.

December 11, 2025: The Critical Transition Deadline

This date marks the formal withdrawal of EN 166 by CEN.

• For New Products: Notified Bodies no longer accept new applications or issue new certificates based on EN 166. Any eye and face protection product entering the EU or UK market for the first time must be certified under EN ISO 16321-1:2022 + A1:2025.
• For Major Modifications: If an existing product certified under EN 166 undergoes any significant material or design changes, it can no longer be updated via an amendment to the old certificate. It must be completely re-certified under the new EN ISO standard.

The 5-Year Certificate Grace Period (Up to late 2030)

If a product obtained an EU Type-Examination Certificate (Module B) under EN 166 before the deadline, that certificate remains legally valid until its expiration date.

• Because PPE certificates typically carry a maximum validity of 5 years, certificates issued just prior to the withdrawal will remain valid for sales and manufacturing until approximately December 2030.
• During this buffer period, existing inventory and legacy products can be legally sold, provided no design modifications are made. However, by the time the certificate expires (no later than 2030), a full transition to the new standard is mandatory.

3. The Grand Consolidation: Streamlining Fragmented Standards

Old European eye protection frameworks were highly fragmented. Designing a pair of multi-functional safety glasses often required manufacturers to cross-reference multiple distinct standards. The new EN ISO 16321 series simplifies this by consolidating those scattered regulations into three primary pillars:

Legacy European Standards (CEN)	New Harmonized International Standards (EN ISO)	Scope & Covered Protection Areas
EN 166 (Core Specifications) EN 170 (Ultraviolet Filters) EN 171 (Infrared Filters) EN 172 (Solar Glare Filters for Industrial Use) EN 1836 (Partially – Sunglasses)	EN ISO 16321-1:2022 + A1:2025	General Occupational Eye & Face Protection Covers non-welding mechanical impacts, chemical liquids, dust, UV, IR, and solar glare protections.
EN 169 (Welding Filters) EN 379 (Automatic Welding Filters)	EN ISO 16321-2	Protection for Welding & Allied Techniques Regulates optical filtering and thermal radiation protections in high-energy welding environments.
EN 1731 (Mesh Face Shields)	EN ISO 16321-3	Mesh Protectors Applies to mesh visors used in forestry and gardening to guard against flying wood chips or mechanical debris.

4. Deep-Dive: Core Technical Differences and Structural Changes

EN ISO 16321-1:2022 + A1:2025 introduces thorough updates to testing equipment, physical measurements, and product classifications. The four most impactful technical shifts include:

1. Ergonomics & “Unobstructed Field of Vision” (A1:2025 Focal Point)

Legacy EN 166 standards allowed relatively flexible side-protection profiles. The 2025 A1 amendment rigorously adopts the ISO 18526-4 international digital and physical headform series.

• Global Anthropometric Data: The new headforms accurately represent modern global demographics, factoring in varied facial widths, nasal bridges, and structures across genders and ethnicities.
• Field of Vision Metrics: When mounted to the test headform, the protector must guarantee a specific, quantified minimum horizontal and vertical unobstructed view, preventing thick frames from creating dangerous visual blind spots in industrial settings.

2. A Restructured Mechanical Impact Coding System

One of the most immediate changes for procurement managers is the retirement of the familiar impact letter markers (S, F, B, A). The new EN ISO 16321-1 updates these codes to align with international ballistics testing velocities:

• Legacy EN 166 Marking: F (Low energy impact 45 m/s), B（Medium energy impact 120 m/s), A (High energy impact 190 m/s).
• New EN ISO 16321-1 Marking: Replaced by a more precise, leveled classification system (e.g., Level C, Level D, etc.). These utilize updated projectile masses and velocities defined under international standards, ensuring more reliable repeatable testing outcomes.

3. Granular Chemical & Liquid Jet Protections

Under the old EN 166 system, passing a basic drop-and-splash test granted a broad liquid protection code of 3 (Liquid droplets). Recognizing that modern petrochemical and laboratory settings present diverse fluid dynamics, the new standard splits this hazard into distinct subgroups:

• Liquids and Droplets: For conventional ambient splashes and droplets.
• Liquid Jets: A brand-new test category assessing resistance to continuous, pressurized streams of liquids originating from a specific direction. This ensures targeted safety for high-pressure washing or chemical valve maintenance.

4. Overhauled Product Markings & Lens Stampings

Because filter standards (UV, IR, Solar Glare) are now consolidated into Part 1, the stampings on the lenses and frames are changing fundamentally:

• Ultraviolet Protection: The old markings (e.g., 2-1.2 or 2C-1.2) are replaced. The new standard introduces the prefix U (or UL for lenses offering enhanced color recognition), followed by the scale number—resulting in markings like U1.2.
• Solar Glare Protection: The old industrial solar glare code prefix (e.g., 5-2.5 or indicators containing L) is eliminated. Lenses are now cleanly categorized into five transmittancy steps from G0 to G4 (ranging from clear to very dark tints).

5. Actionable Roadmap for Manufacturers and Procurement Managers

To prevent supply chain disruptions, border delays at customs, or compliance gaps, companies must proactively adjust their operations.

For PPE Manufacturers and Exporters

• Execute a Gap Analysis: Submit your current EN 166 product designs to accredited third-party testing laboratories (such as BSI, SGS, TUV, or PZT) for pre-testing against the A1:2025 parameters, particularly validating side-protection boundaries and headform visibility constraints.
• Transition EU/UKCA Type Examinations: Discontinue any legacy EN 166 certification pipelines. Route all upcoming and redesigned models directly through EN ISO 16321-1:2022 + A1:2025 pathways to maximize your certificate’s 5-year commercial life cycle.
• Update Molds, Laser Etchings, and Documentation: Redesign frame and lens injection molds to account for the new U and G marking codes. Concurrently update your User Instructions (IFU), packaging labels, and official Declarations of Conformity (DoC).

For EHS (Environmental Health & Safety) Officers and Corporate Buyers

• Audit Internal Inventories: Check your current PPE suppliers to determine if they have begun transitioning their certifications. While existing EN 166 inventory remains legal to use through its buffer period, prioritize suppliers offering EN ISO 16321 compliant options during upcoming contract renewals.
• Revise Internal Safety Manuals: Update internal procurement protocols and training literature. Ensure that older directives (e.g., “Look for code 3 for chemical splashes”) are progressively updated to account for the incoming integrated ISO hazard codes.

6. Summary

The complete replacement of EN 166 by EN ISO 16321-1:2022 + A1:2025 is an irreversible step forward for international industrial safety. While valid legacy EN 166 certificates will continue to taper off during their remaining grace periods, forward-thinking enterprises that aggressively transition to the unified global standard will secure a distinct competitive advantage in the international PPE market.

🔗 Official Announcements and Authoritative Sources

To cross-reference this technical transition or to verify compliance criteria with your engineering teams, consult the official international regulatory databases below:

1. European Committee for Standardization (CEN) Database:
   • Standard Reference: EN ISO 16321-1:2022
   • Latest Amendment: EN ISO 16321-1:2022/A1:2025
   • Note: Detailed timelines regarding the formal withdrawal (downdate) of EN 166 can be monitored via the CEN Standard Search Portal.
2. International Organization for Standardization (ISO):
   • Official Document: ISO 16321-1:2021/Amd 1:2025
   • Note: This repository lists the exact international engineering provisions, test headform geometries, and physical testing setups updated in the 2025 Amendment 1 text.
3. Notified Body & Testing Authority Technical Bulletins:
   • Leading international PPE certification bodies—such as SATRA Technology, BSI Group, and SGS—have published dedicated regulatory compliance whitepapers detailing the practical cessation of EN 166 intake, establishing the absolute baseline for global compliance strategies.