Choosing the right lens coatings for protective eyewear

WHEN IT comes to selecting the appropriate safety eyewear lens coatings, the process can be made straightforward by following some simple rules. 

Coatings must be appropriate to the task in hand. If unsuitable lens coatings are used there is the risk of unwanted consequences such as eye irritation, lack of compliance and confidence in PPE, low worker morale, and subsequently reduced efficiency.  

Types of lens coating 

Certain lens coatings are appropriate and effective for some jobs, but not for others. For example, coated lenses that are permanent anti-fog on both sides, scratch resistant and antistatic are particularly suitable for work in high humidity or polluted circumstances, while extreme coatings which separate anti-fog and scratch resistant lens coatings allowing them to perform at a much higher level and on the side of the lens where the coating is needed most, are ideal for work in tough and dirty environments. 

In welding, a grey-tint welding filter lens, as well as providing 100% ultraviolet and infrared protection and glare reduction, also gives perfect natural colour recognition, unlike traditional green-tinted welding lenses, which can alter colours. Correct colour vision is vital in welding tasks where safety can depend on the accurate recognition of colours in safety signs and signals in environments such as foundries, steelworks, aerospace or engineering. 

In workplace settings with a high risk of small particles, dirt and dust flying around, such as in steel making, mining or construction, highly scratch-resistant coatings are a must, preferably on both sides of the spectacle or goggle. 

In working situations such as in paper, food, textiles and refrigerated warehouses with high humidity levels and persistent condensation, permanent, hydrophilic fog-resistant coatings are essential for safe and non-interrupted effective working. 

In the past, anti-fog coatings used to wear or wash off quickly, so their permanence is a big step forward in increasing performance and life span of a product even after repeated cleaning. The modern hydrophilic coating becomes sponge-like, absorbing moisture without becoming saturated, so that the wearer does not have to take off their spectacles or goggles to clear any fog, enhancing both safety and wearer compliance.

Chemical- and biological-resistant coatings are needed for whenever chemicals are worked with, especially in medicine, food and waste management. They are also needed to protect against hazardous liquids, toxic dust, gas and vapours. 

In jobs that require frequent change from indoor to outdoor environments, a 20% silver mirror sun tint lens could be used to allow workers to see in both light environments.

Selecting the right lens coating

So how can eyewear procurers decide on the perfect lens coating for the job in hand and the relevant working conditions? Good manufacturers can assist companies in selecting the proper eyewear and lens coatings for specific work environments.  However, it should not be a difficult or daunting task and it is, in fact, very easy to make the right choice using a foolproof coatings selection system, which caters for most working conditions and industries.

The most efficient way to do this is to use a ‘spider graph’ selection chart. With this method, it is easy to plot and opt for the right coating for the right job, so eliminating wasteful trial and error, saving time and costs, and increasing efficiency.  

The method is straightforward. The workplace conditions in terms of temperature (hot, cold) are entered on the horizontal axis of the chart, the air humidity (dry, wet) is described on the diagonal axis, and the degree of dirt (dirty, clean) specified on the vertical axis. When these three points are joined to form a triangle, the largest area will indicate the appropriate lens coating for the defined area of use.

A set amount of choices is available to cover most working conditions, making the selection of the right lens coating for a particular function very simple. 

For more information:

www.bsif.co.uk

Tel: 01442 248744