European Standard EN 344:1997, "Safety, protective and occupational footwear for professional use," was developed by the CEN/TC 61 technical committee ("Foot and leg protectors"), with the secretariat held by BSI. This standard specifies requirements for the design, structure, and performance of safety and protective footwear, covering components such as the complete shoe, upper, lining, tongue, insole, and outsole. The test methods prescribed in the standard are similar to those in other comparable standards, and the underlying principles are generally applicable to most anti-static safety footwear. Key performance indicators include:
Impact resistance of the toe cap
Impact tests are conducted using a steel impactor of a specified weight; the clearance height beneath the toe cap upon impact must remain above a specified minimum value, and the toe cap must not exhibit any cracks that penetrate through the material along the test axis. It should be noted that standards across different countries vary regarding impactor weight and specifications, drop height, and testing machine construction; these differences must be taken into account during actual testing.
Puncture resistance
The testing machine is equipped with a pressure plate, and the pressure plate is equipped with a test nail. The test nail is a head with a truncated tip. The hardness of the nail head should be greater than 60HRC. Place the shoe sole sample on the chassis of the testing machine in such a position that the test nail can pierce through the outsole. The test nail pierces the sole at a speed of 10 mm/min ± 3 mm/min until it penetrates.
Record the maximum force required until it penetrates. Select 4 points on each sole for testing (at least 1 point of which is at the heel). The distance between each point is not less than 30 mm and the distance from the edge of the insole is greater than 10 mm. There is a bottom with anti-slip blocks, which should be pierced between the blocks. Two of the four points should be tested within a distance of 10-15 mm from the edge line where the base corrugation is located. If humidity will affect the results, the soles should be immersed in deionized water at 20℃±2℃ for 16±1h before testing.
Electrical Properties
After conditioning the footwear in both dry and humid atmospheres, the shoe is filled with clean steel balls and placed on a metal probe assembly; using specified resistance testing equipment, the electrical resistance between the two front probes and the third probe is measured. Generally, conductive footwear requires a resistance of no more than 100 kΩ, while antistatic footwear requires a resistance between 100 kΩ and 100 MΩ.
