You are holding a pair of safety glasses and there is a short string of characters stamped on the temple, something like Z87+ U6. That string is the entire specification. This guide decodes it, then answers the harder question behind it: whether the job in front of you calls for glasses, goggles or a face shield.
Where the markings live
Under ANSI/ISEA Z87.1 the manufacturer's mark and the applicable code letters are stamped on the frame or housing, and again on the lens where the lens itself carries a rating. Frame marks describe the device; lens marks describe the lens. A frame stamped Z87+ fitted with unmarked replacement lenses is no longer a certified impact protector, which is why replacement lenses should always come from the same product line.
The first thing to look for is whether a plus sign is present. Everything else is secondary.
Z87 versus Z87+: the impact question
Z87.1 sorts protectors into non-impact and impact rated. A non-impact device is marked Z87 and must survive the drop ball test: a 25.4 mm (1.0 in.) steel ball weighing 68 g (2.4 oz) released from 127 cm (50 in.) above the lens.
An impact-rated device is marked Z87+ and has to pass three considerably harder tests:
- High mass impact. A steel projectile with a 30 degree conical tip, weighing at least 500 g (17.6 oz), dropped from 127 cm (50 in.) onto the protector mounted on a headform.
- High velocity impact. A steel ball fired at the protector at a speed set by device type, at multiple impact points.
- Penetration. A weighted needle assembly of 44.2 g (1.56 oz) dropped from 127 cm (50 in.) onto the lens.
The high velocity speeds are where the three device families separate, and they explain a lot about how each one is built:
| Device type | 6.35 mm steel ball | 6.0 mm steel ball |
|---|---|---|
| Spectacles, readers, magnifiers | 45.7 m/s (150 ft/s) | 50.9 m/s (167 ft/s) |
| Goggles, full-facepiece respirators | 76.2 m/s (250 ft/s) | 84.7 m/s (278 ft/s) |
| Face shields, welding helmets, loose-fitting respirators | 91.4 m/s (300 ft/s) | 101.5 m/s (333 ft/s) |
If there is any flying particle hazard in the task, grinding, chipping, machining, striking tools, powder-actuated fastening, specify Z87+ and nothing less. Plain Z87 belongs on tasks where the eye risk is glare, nuisance dust or light chemical exposure. Most of what you will find in safety glasses is impact rated, but confirm it on the frame rather than on the product photo.
The rest of the code letters
| Mark | What it means |
|---|---|
| Z87 | Meets the standard; not impact rated |
| Z87+ (or + on a lens) | Impact rated |
| Z87-2 | Prescription (Rx) protector |
| D3 | Splash and droplet protection |
| D4 | Dust protection |
| D5 | Fine dust protection |
| U + scale number (U2 to U6) | Ultraviolet filter; higher number blocks more UV |
| R + scale number (R1.3 to R10) | Infrared filter |
| L + scale number (L1.3 to L10) | Visible light (glare) filter |
| W + shade (W1.3 to W16) | Welding filter shade |
| V | Variable tint (photochromic) |
| S | Special purpose lens |
| X | Passed the standard's anti-fog test |
| H | Designed for a smaller head size |
Two groups here get misread constantly. The D codes are pass or fail hazard tests, not a ladder. D3 is judged by whether a liquid splash produces coloration inside marked circles on the test form; D4 by whether the lens keeps at least 0.80 of its original reflectance after a dust chamber exposure; D5 by a fine dust version of the D3 coloration check. A goggle can carry D3 alone, or D3 D4 D5 together. The scale numbers are filters, and they are not interchangeable across letters. A dark lens marked L is a glare filter and is not a substitute for a welding filter marked W.
Glasses, goggles or a face shield?
Safety glasses
Spectacles with permanent or detachable side protection are the default for impact hazards; OSHA requires side protection wherever there is a hazard from flying objects, and accepts clip-on or slide-on side shields that meet the standard. What glasses cannot do is seal. They will not stop a splash arriving from below the lens or a fine powder that drifts in around the frame. For outdoor glare, polarized wraparound styles such as the MCR Safety Hulk HK4 are worth comparing on frame markings and lens tint together.
Goggles
Goggles seal against the face, so they are the correct primary protector for chemical splash and for dust fine enough to defeat a spectacle. OSHA's own selection guidance calls for indirectly vented goggles for chemical splash, direct or indirect ventilation for nuisance dust, and indirect or unvented goggles for fine dust. That maps cleanly onto the marks: look for D3 on splash safety goggles, and D4 or D5 where the hazard is airborne particulate.
Face shields
Face shields protect the face, not just the eyes, and they are secondary protectors. OSHA's selection chart repeatedly specifies a face shield worn over spectacles or goggles for impact, heat, chemical splash and dust hazards; a shield on its own leaves the eyes exposed from underneath and around the edges. Choose the window to the hazard rather than by price. A clear anti-fog visor such as the Honeywell Uvex Bionic Shield suits splash and impact work, while a tinted acetate window like the SureWerx Jackson F30 in dark green is aimed at radiant heat and glare. Crews already in hard hats should look for slot-mounted headgear rather than a second suspension, and compare window materials across the face shields range.
Editions: 2020, 2025, and what OSHA actually enforces
Z87.1 was revised in 2020, and ANSI/ISEA published Z87.1-2025 on 8 January 2026. The 2025 edition expands and clarifies product marking requirements, including guidance on prescription lens carriers, tightens the language around impact testing, lens haze and minimum coverage, and adds a cross-reference to ANSI/ISEA Z87.62-2021 on protection against sprays of blood and other potentially infectious materials.
OSHA, meanwhile, still incorporates ANSI/ISEA Z87.1-2010, ANSI Z87.1-2003 and ANSI Z87.1-1989 (R-1998) by reference in 1910.133(b). The practical reading: eyewear built to a current edition satisfies OSHA, and there is no compliance reason to scrap stock marked to an older edition, but write new purchasing specifications to the newest edition you can source.
A short buying checklist
- Flying particles anywhere in the task? Z87+ only, no exceptions.
- Liquid chemicals? Sealed goggles marked D3, with a shield over them for pouring and decanting.
- Fine dust or powder? D4 or D5 with indirect or no ventilation.
- Welding, cutting or torch work? A W shade chosen from the OSHA shade table, never a tinted L lens.
- Prescription wearers? Either a Z87-2 Rx protector or an over-the-glasses design that does not disturb the prescription lenses.
- Fogging is the most common reason PPE gets pushed up onto a forehead. Specify X-marked anti-fog lenses and keep a lens cleaning station where the work happens, not in the supply room.
If you are building a program rather than replacing a single item, start from the hazard assessment and work across the whole eye and face protection range, so that the shield, the goggle and the everyday spectacle are all specified against the same list of tasks.
This guide is educational. Selection and compliance remain the employer's responsibility under the applicable standard.