Our eyes are the most sensitive, exposed part of the body and the effects of an eye injury can be life-changing and devastating. The outer layer of the eye, the cornea, is vulnerable as it is only 0.5mm thick, making it easy for foreign objects and hazardous substances to penetrate.
Occupatations such as welding, chemistry and forestry obviously require eye and face protection, but many other hazards are present in almost all environments which might often be overlooked. Before starting a task, think about what you're about to do and ask yourself 'what are the risks?'
Working outside, as a gardener for example, presents minor risks; scratches to the eyes from twigs or canes; chemicals in weedkiller; soil particles getting into the eye - soil and even pond water can contain a nasty bug called acanthamoeba which causes corneal ulcers. Sunglasses are a great, simple way to stay safe outdoors and will also shield your eyes from harmful UV rays.
If using chemical cleaning products you should take care to avoid contact with the eyes. If contact occurs with any chemical substance, or dirt, you should immediately rinse them well with fresh, cold water, or eyewash - this should be an item that is included in your workplace first aid kit.
Nail and staple guns can cause terrible injury if something goes wrong. There is always the risk that a nail may be deflected or that splinters could be ejected towards the operator. Accident analysis has shown that the vast majority of eye injuries caused by nail guns would have been avoided if eye protection had been worn.
This video highlights these risks and the importance of wearing eye protection (warning; it does contain some images of eye injury) > http://bit.ly/1jG3YEz
HSE have this short guide to working with nail guns, here.
When selecting safety eyewear you first need to consider the tasks for which you will be wearing them and the hazards and substances you will be in contact with.
The general safety standard for eye protection is EN166 but within this, different specifications and values will be designed for specific hazards.
EN175 sets the specification for Eye and Face Protection
EN379 sets the specifications for Personal Eye Protection – Automatic Welding Filters
EN1731 covers mesh type Eye and Face Protectors
Lenses with a filtering effect are rated using scale numbers. The scale numbers consist of a code number and a shade number separated by a hyphen – except for welding filters which have no code number. Higher shade numbers have a stronger filtering effect (eg, they are darker for welding).
No code number but a shade number between 1.2 and 16. Suffix 'a' denotes filter for use in gas welding with flux .
2 or 3 code number denoting UV filter without or with good colour recognition, respectively. Plus a shade number between 1.2 and 5.
Infra Red Filters.
4 code number for IR filters, plus a shade number between 1.2 and 10.
Using the scale numbers, an Infra Red filter with a shade number of 4 would be written as 4-4.
A UV filter, with good colour recognition and a shade number of 5 would be written as 3-5.
The optical class denotes the optical quality of the lens on a scale of 1, 2 or 3 with Class 1 being the best.
Applicable to both lenses and frames.
S – increased robustness (lenses only)
F – high speed particles, low energy impact (any type)
B – high speed particles, medium energy impact (goggles and faceshields only)
A – high speed particles, high energy impact (faceshields only)
Fields of Use
3 - resistant to liquid droplets (goggles) or liquid splashes (faceshields, but not mesh)
4 – resistant to coarse dust particles
5 – resistant to gas and fine dust particles
9 – resistant to molten metals and hot solids
9 – resistant to molten metals and hot solids.
Other Lens Markings
You might also see these markings used;
K or AS – resistant to surface damage by fine particles/ Anti-Scratch
N or AF – resistant to fogging
On some products you may see them labelled with ANSI z87. This is the American National Standards Institute and their rating may appear on products from American manufacturers. Z87 is the equivalent of our EN166, a specification or standard for Personal Eye and Face Protection.
Looking at some of the products on our Eye Protection page, we can see many examples of these markings in use.
We can see that this product is labelled as conforming to EN166. This means that it meets the minimum requirements of safety eyewear, but would not be suitable for more specialist applications. This product will protect the wearer from minor hazards.
This product is labelled EN166 4.9.BT So we know that it meets the required EN166 spec for safety glasses. The 4 & 9 tell us that its fields of use. It is resistant to coarse/ large dust particles (4) and molten metal and hot solids (9). The lettering denotes its mechanical strength. 'B' shows that it is resistant to high speed particles, medium energy impact and 'T' means it is resistant to these hazards at extremes of temperature. It is also labelled ANSI z87 showing that this product also meets the American standards for Eye and Face Protection.
We can see that these are high quality goggles. They are labelled EN166 1B 3459 so conform to the safety standard EN166. 1B denotes the optical class (lens quality) with 1 being the highest and 'B' denotes the mechanical strength - resists high speed particles, medium energy impact. The fields of use 3459 mean that these goggles meet all fields of use; liquid droplets (3); large dust particles (4); gas and fine dust (5); and molten metal and hot solids (9).