Rubber mats are tested for electrical resistance and other properties to ensure their effectiveness in preventing electric shock. Testing methods include using high-voltage test apparatus to measure resistance and checking for any weak spots in the compound to ensure the matting is compliant with the relevant guaranteed standards, which include IEC 61111. Class 0 - class 4, ASTM D178 class 1 - class 5 and similar regulations that are accepted in countries around the world.