These boots are made for warming

Kettering, UK – Footwear testing and research organisation SATRA has recently developed a rating system to indicate the thermal insulation performance of footwear to consumers.

In creating the system, the UK body took its cue from the familiar ‘tog’ ratings for bedding duvets, which is a readily understood way of comparing the performance of products on the market.

While, for many applications, footwear is designed to keep the wearer’s feet warm, it is often a challenge to easily communicate this performance level to the customer at the key point of sale setting, said the Kettering-based group.

SATRA, therefore, developed a simple scale to “demystify thermal performance” called the ‘footwear effective tog’ (FET) level, which is identified by its ‘TM436 whole shoe thermal insulation and cold rating test’.

To calculate an effective FET value, the test measures the thermal performance properties of footwear, generates both an ‘R’ value and a cold rating to evaluate the insulation performance.

The FET scale runs from 1 to 20 – the higher the number, the more thermally insulating the product is, thus allowing customers to select footwear suitable for a specific end use.

According to SATRA, the FET level required by the wearer depends on the activity for which the footwear is worn.

For example, it explains, when working in a freezer at -15°C, a worker driving a forklift truck – a low-movement activity – is likely to require footwear with a FET rating of up to 15.

By contrast, it said, a worker who is walking around picking or moving stock – a high-movement role – would require footwear with a FET rating of up to 10.