A step change in footware

There are many instances where specialist footwear is required to be worn in a cleanroom environment and the hygiene processes for the use of footwear within the different sectors will be specific to each company and the products it makes. This article reviews the main issues to consider when choosing the right footwear for cleanroom personnel, and looks at some of the latest developments in the materials being used to produce products.

There is a wide variety of properties offered by different industrial footwear including: safety toe caps, dual or single density sole units, antistatic, chemical-, fire-, scratch- and tear-resistance, micro fibre or natural fibre, breathability, comfort, polyurethane soles, slip-resistance and washability.

It may seem like a long list just for a pair of shoes but these are some of the key considerations that need to be addressed when selecting safety footwear for the cleanroom sector.

Unlike heavier industries, where physical protection tends to dominate the list of needs, requirements for shoe selection within the cleanroom sector are far broader.

While developments in fabrics used both on the exterior and interior of cleanroom shoes have improved in performance, they have also given those with responsibility for quality control and health and safety more to think about in the decision-making process.

So what are the main considerations that need to be addressed when selecting safety footwear for the cleanroom sector?

Which material?

Where traditionally leather was used as the key material for cleanroom footwear, developments in materials manufacture in recent years has meant that alternatives are now available that provide performance benefits over leather.

One example is Wat-Out – a micro-fibre that reproduces the structure of leather but with the added benefit of being repellent to chemicals such as solvents, acids, oils, alkalis, animal fats and water. The material is also highly breathable, extremely lightweight and antistatic, in addition to being flame proof, scratch- and tear-resistant.

“The advent of micro fibre technology has not only created greater choice but has also enabled safety footwear manufacturers to create products that have all of the features of leather but with additional benefits over and above leather, such as chemical resistance,” says Stuart Thorne of Jal Group, Europe’s largest safety footwear manufacturer. “These micro fibres are also more durable than leather, bringing real advantages to users.”

In addition to improved performance, new fibres can also provide additional benefits in the shape of lightness and breathability improving wearer comfort significantly.

“Despite the fact that the cleanroom is an extremely controlled environment, including temperature control, the feet will perspire. With 250,000 sweat glands, a pair of feet is capable of excreting as much as half a pint of moisture every day,” says Thorne.

“With new fibre development, shoes now allow the feet to effectively breathe, greatly improving wearer comfort. It is also important to remember that one of the major causes of footwear breaking down is through the moisture that leaches out of the skin and into the fabric of the shoe. If that moisture is not allowed to permeate out through the footwear it will remain in the shoe and break it down from the inside out, reducing its life expectancy,” adds Thorne.

Product design

Given the need to reduce particulate levels and the threat of cleanroom contamination as much as possible, safety shoe designs that are minimal in their approach should be selected.

Slip-on shoes should be the preferred options with minimal stitching again to reduce opportunity for contamination.

Comfort

It goes without saying that providing footwear that is highly comfortable is a minimum requirement. But given the level to which cleanroom personnel will be on their feet – often working at the same work station for long periods during a shift - this requirement is magnified further.

“Foot fatigue brought about by standing in the same spot in basic footwear that is perhaps too tight, ill fitting or that does not have a comfortable footbed and sole unit. In addition to being uncomfortable for the feet, ill fitting shoes that do not provide high levels of comfort can also lead to wider issues such as stiffness of the back,” says Thorne.

Slip-resistance

While most cleanroom environments involve dry processes, it is important to remember that behind manual handling injuries, slips and trips have, over the past five years, been either the second or third most common injury in the sector. As a result it is important to consider the under sole protection provided where a slip hazard is concerned.

“If there is any likelihood for a liquid or substance spilling on the floor during the cleanroom process, it is important that a sole unit that can displace the spilled liquid or substance rather than clog the sole and therefore increasing the risk of slipping is selected,” says Thorne.

“Sole units should be designed for a specific purpose and it is important to find out the slip resistance of a sole unit when deciding on which footwear to choose.”

Chemical protection

The need for chemical protection will once again depend on the processes taking place within the cleanroom. Where chemicals are used in the cleanroom and there is a risk of spillage and foot contact, chemical protection becomes a pre-requisite.

The key step in the process is to identify the type of chemicals being worked with. Once this has been done, advice from a leading safety footwear manufacturer should be sought to identify the right shoe material to provide the right levels of protection should a spill occur.

Physical protection

While it may not seemingly be the most hazardous industry for crush injuries, the fact remains that these type of injuries do occur in cleanrooms. Where materials are carried from one area to another or there is the risk of something being dropped from a workbench, then physical protection needs to be incorporated into the safety footwear through a 200 Joule protective toecap.

There is a diverse range of factors that need to be considered when selecting safety footwear for a cleanroom environment. Which features drive the decision making process will depend largely on the type of activity taking place in a particular cleanroom, the hazards encountered and specific performance required.

With technology providing improved performance over traditional footwear, it is important to understand the company’s needs and to consider the needs of the wearer.