Safety Goggle Marking Guide

When selecting a pair of safety goggles, it’s important to match your choice to the hazards you will be facing. The frames and lenses of your safety goggles are etched with a series of letters and numbers, each corresponding to a different hazard that they can protect you against. While these symbols can seem daunting at first, they are arranged in a specific order to make them as simple to read as possible.

In this article, we’ll explain what each of these markings mean, and how to go about deciphering them when selecting your safety goggles. The first, and most basic, standard that you should look for is EN 166, which should be the minimum standard present on all eye protection. After that, it's time to look at frame markings and lens markings. Frame markings are divided into two categories: Strength Designation and Style and Protection. Lens markings are divided into four categories: Radiation Protection, Light Transmission, Optical Quality and Lens Properties. 

As a point of reference, we will use the frame and lens markings of the Supertouch E10 Safety Glasses:

• Frame marking: CE STPPE EN 166 S 3-1.2 
• Lens marking: CE 3-1.2 STPPE 2 S K

Frame Standards

Frame markings are typically made up of three ratings, and the name of the manufacturer (which, in our example is represented by "STPPE" – Supertouch PPE). These three standards are: the European Standard (EN 166), Strength Rating (S), and Style of Protection (which our example glasses do not adhere to). In our example code, the additional 3-1.2 refers to UV protection, which isn’t included by all manufacturers in their frame markings.

Strength Rating Breakdown

There are four possible frame strength ratings that will protect you from the following:

• S: Impact with a small object travelling at up to 12 meters per second
• F: Impact with a small object travelling at up to 45 meters per second
• B: Impact with a small object travelling up to 120 meters per second
• A: Impact with a small object travelling up to 190 meters per second
• T: Suitable for use at extreme temperatures

Style and Protection Breakdown

There are four possible Style and Protection ratings, providing:

• 3: Liquid splash protection
• 4: Protection from dust particles over 5 microns
• 5: Protection from dust particles under 5 microns
• 8: Resistance to electrical short circuit arcs
• 9: Resistance to penetration from hot solids

Example: Referring to the markings on our E10 Safety Glasses, we know they are resistant to impacts with small objects up to 12 meters per second, and are compliant with EN 166. Our example marking doesn't include a Style of Protection Rating, as these are more commonly associated with safety goggles, and not the glasses we've used as our example.

Lens Standards

Lens markings are usually made up of four standards, and the name of the manufacturer. These are Radiation Protection (3 in our example markings), Light Transmission (1.2), Optical Quality (2), and Lens Properties (S and K).

Radiation Protection Breakdown

There are 5 possible Radiation Protection ratings, providing:

• 2: UV protection with a coloured light filter that may alter colour recognition (corresponding with EN 170)
• 2C or 3: UV protection with a clear light filter, allowing good colour recognition (corresponding with EN 170)
• 4: Protection with infrared filters (EN 171)
• 5: Protection from sun glare (EN 172)
• 6: Protection from sun glare with infrared filters (EN 171 + EN 172)

Light Transmission Breakdown

There are four possible levels of Light Transmission ratings, allowing the following amount of light to pass through the lens:

• 1.2: Between 74.4% and 100%
• 1.7: Between 43.2% and 58.1%
• 2.5: Between 17.8% and 29.1%
• 3.1: Between 8% and 17.8%

To put these numbers into context, goggles with low levels of light transmission should be used in very bright environments, and high levels of light transmission are suitable for areas with comfortable lighting. 

Optical Quality Breakdown

There are three levels of Optical Quality, each referring to a different optical class:

• 1: Class 1 - High quality for regular use
• 2: Class 2 - Medium quality of occasional use
• 3: Class 3 - Low quality for rare use

Lens Property Breakdown

There are seven possible Lens Property ratings:

• S: Protection against impact with a small object travelling at up to 12 meters per second
• F: Protection against impact with a small object travelling at up to 45 meters per second
• B: Protection against impact with a small object travelling at up to 120 meters per second
• A: Protection against impact with a small object travelling at up to 190 meters per second
• T: Ability to withstand extreme temperatures
• N: Resistance to fog
• K: Scratch resistance
• 8: Resistance to electrical short circuit arcs
• 9: Resistance to penetration by hot solids

Example: Referring to the lens markings on our E10 Safety Glasses, we know they provide UV protection with a clear light filter (3) , allow between 74.4% and 100% of light to pass through (1.2), are medium quality for occasional use (2), and are scratch resistant (K) and impact resistant (S).

Still Unclear?

While we've broken down the main features and standards you need to know when choosing your safety goggles, these things can be tricky. If you have any questions or comments about safety goggle and glasses markings, let us know in the comments section below and we'll get back to you as soon as we can.