Products and services

Metal midsoles in safety footwear

In an attempt to raise the standards of PPE in the UK, safety company Arco tested the chromium content of metal midsoles in 14 Class 1 footwear products at its Product Assurance Laboratory.  Its product assurance team found that seven of the 14 products contained less than 0.2% of chronium.


Midsoles must be able to resist a penetration test using a nail with a force of 1100N and a corrosion test in a 1% sodium chloride solution. 

In order to adhere to EU standard EN ISO 20345 2011, midsoles must be able to resist a penetration test using a nail with a force of 1100N and a corrosion test for 48 hrs in a 1% sodium chloride solution. Furthermore, in its publication ‘Toe Caps and Penetration Resistent Inserts (BULSEP2013)’, SATRA has indicated that to ensure current standards for Class 1 footwear products are met,  metalic midsoles should be made of stainless steel also known as high chromium  steel, as it is likely that only stainless steel will pass the test. These steels contain generally a minimum of 10.5% chromium, the element  that prevents the steel from corroding. A true stainless steel midsole has high corrosion resitant properties, thus ensuring the long term protection from penetration.  

During an investigation conducted by Arco’s Product Assurance team, it was identified that 7 of the 14 products contained less than 0.2% of chromium. Carbon steel inserts containing low levels of chromium may pass an initial puncture resistance test, but are likely to corrode over time especially if the sole of the footwear has been penetrated. This can then pose significant risk to the wearer who would be unaware their midsoles are no longer compliant or fit for purpose. 

To further complicate matters for buyers and end-users, the use of stainless steel midsoles in the construction of footwear is not immediately evident and purchasers are relying on the CE mark being accurate. Even though the manufacturer is responsible for compliance of its products, they do not always have the resources in place for regular testing. Additionally, less reputable manufacturers or importers can make changes to the product once CE certification has been gained for the products which will then affect the product’s performance

The BSIF has recently written to its members urging them to redouble their efforts in making sure that their suppliers can provide all the evidence required to guarantee the quality and performance of the products in their ranges.  It also plans to re-launch the Registered Safety Supplier Scheme with new conditions requiring independent testing to ensure products sold still perform to the EN test clauses. 

To ensure the safety of workers, customers can take the following steps:
•    Ask your suppliers for a declaration of conformity that shows the original certification for the PPE you are purchasing.  
•    Ask your supplier to provide evidence that they only use stainless steel midsoles in all class 1 products. 
•    Ask your suppliers to define their process for sample testing to ensure safety products continue to meet the required standards.
•    Ensure your suppliers are members of the BSIF Registered Safety Supplier Scheme.
•    Ask your suppliers to define their process of quality assurance at the manufacturing facility to ensure the products are being manufactured as they were originally certified. 
•    Always buy from a trusted source.

Remaining vigilant as an industry and ensuring suppliers of PPE follow rigorous processes and have ongoing testing in place will help protect workers.


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