Sep. 03, 2026
1 mm = 1,000,000 nm
Class (IEC / ANSI) | Wavelength Range (IEC 60825 1) [nm] | Wavelength Range (ANSI Z136.1) [nm] | Power Limit (Continuous Wave) | Core Risk and Description |
Class 1 / I | 180 – 1,000,000 | 180 – 1,000,000 | ≤ 0.39 mW (visible) | Safe under reasonably foreseeable conditions. |
Class 1M / IM | 302.5 – 4,000 | 302 – 2,800 | No simple upper limit, but total power < 0.5 W | “M” stands for Magnification. Safe for the naked eye, but hazardous when viewed with magnifying optics (e.g., loupes, telescopes). |
Class 1C | not specified | not specified | application dependent | IEC only – for medical, diagnostic, or cosmetic laser products that contact the skin or internal tissues. |
Class 2 / II | 400 – 700 | 400 – 700 | ≤ 1 mW | Visible light only. The human blink reflex (approx. 0.25 s) provides protection. |
Class 2M / IIM | 400 – 700 | 400 – 700 | ≤ 1 mW | Visible; safe for brief naked eye exposure, but hazardous when viewed with optical instruments. |
Class 3R / IIIa | 180 – 1,000,000 | 180 – 1,000,000 | 1 – 5 mW | “R” stands for Reduced requirements. Direct intrabeam viewing carries a potential risk. |
Class 3B / IIIb | 180 – 1,000,000 | 180 – 1,000,000 | 5 – 500 mW | Direct or specular reflections cause severe eye damage; also hazardous to skin. |
Class 4 / IV | 180 – 1,000,000 | 180 – 1,000,000 | > 500 mW | Highest hazard level. Direct, specular, and even diffuse reflections can injure eyes and skin; also a fire risk. |
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Do not apply directly without verification – The table above is a highly simplified reference. The actual Accessible Emission Limit (AEL) depends on factors such as wavelength, pulse duration, beam diameter, and other parameters.
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Differences in standard revisions – Standards are updated periodically. For instance, some sources indicate that the 2026 revision of ANSI Z136.1 may raise the upper limit for Class 3R visible lasers to 15 mW.
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FDA specific requirements – The U.S. FDA regulations are mandatory and enforceable. Their classification system (Class I, IIa, II, IIIa, IIIb, IV) differs slightly from IEC. For example, laser pointers sold in the U.S. are strictly limited to Class IIIa (≤ 5 mW).
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