Users involved in the production, use, transportation, and emergency response with liquid chemicals can be exposed to numerous compounds capable of causing harm upon contact with the human body. The deleterious effects of these chemicals can range from acute trauma such as skin irritation and burn to chronic degenerative disease, such as cancer. Since engineering controls may not eliminate all possible exposures, attention is often placed on reducing the potential for direct skin contact through the use of personal protective equipment (PPE) that resists permeation, penetration and degradation. The test method described in this part of EN 16523 are intended to be used to evaluate the barrier effectiveness of materials used for protective clothing, gloves and footwear materials against ingress by liquid chemicals. This test method provides various options for reporting test results in terms of breakthrough time, permeation rate and cumulative permeation to allow a comparison of PPE material permeation resistance. These parameters are key measures of the effectiveness of a material to act as a barrier to the challenge chemical. Such information is used in the comparison of PPE materials during the process of selecting PPE for protection from hazardous chemicals. Long breakthrough times, low permeation rates and low cumulative permeation mass are characteristic of high level permeation resistant materials.