Mechanisms that govern chemical resistance in gloves
Two mechanisms govern chemical resistance in gloves: permeation and degradation.
Permeation occurs when a chemical migrates through the glove material at a molecular level. It measures how quickly and effectively a chemical can penetrate through the glove, even if the glove appears intact.
Degradation happens when a chemical damages the glove’s structure, leading to weakening, swelling, or breakdown of the material. This process compromises the glove’s strength and protective ability, reducing its effectiveness against chemicals.
Permeation Test
A permeation test measures how quickly a specific chemical passes through a protective material, such as a glove, and the time it takes for the chemical to be detected on the other side. This test adheres to stringent standards, such as EN 16523-1:2015+A1:2018 and ISO 374-1:2016+A1:2018. These standards ensure the material’s effectiveness in providing chemical protection.
For gloves, permeation testing assesses the time it takes for a specific chemical to penetrate the glove at a given permeation rate (1 μg/cm²/min). The EN 16523-1:2015+A1:2018 standard, linked to ISO 374-1:2016+A1:2018, is widely recognized and dictates the procedures and conditions for conducting permeation tests. During these tests, the glove is immersed in a chemical under laboratory-controlled conditions of continuous contact at room temperature at 23°C +/- 2, relative humidity (RH) 50% +/- 5.
Permeation Test Procedure
The permeation test procedure involves assessing the resistance of glove materials to chemical penetration. A sample of the glove material is mounted in a test cell, separating it into two chambers. While, one chamber is exposed to the chemical, the other contains a collection medium, typically a gas or liquid. The chemical permeates through the glove material, and its concentration is measured in the collection chamber over time.
The breakthrough time (BTT) is recorded as the time taken for the chemical to be detected on the other side of the material at a specific threshold. This test determines the glove’s protective capabilities against hazardous chemicals.
Interpreting Permeation Test Results
Permeation test results are categorized into performance levels from 1 to 6, based on normalized breakthrough time (NBT) values. Higher performance levels indicate greater resistance to permeation:
Chemicals Tested in the Chemical Permeation Test
According to ISO 374-1:2016+A1:2018, 18 chemicals are tested in the chemical permeation test. The table below showcases the code letters, chemicals, CAS numbers, and classes of the chemicals:
Classification of Chemical Gloves Based on Performance Level
Gloves are classified as Type A, B, or C based on the NBT. The following table showcases how the gloves are classified according to the ISO 374-1:2016+A1:2018 standard:
Selecting Chemical-Resistant Gloves Based on Permeation Testing
Begin by identifying the specific chemicals you will handle. Refer to safety data sheets (SDS) to understand the hazards and properties of these chemicals.
Select gloves with breakthrough times that exceed the expected duration of exposure to each chemical. This ensures that the gloves provide adequate protection throughout the task.
Permeation testing is a critical component in selecting chemical-resistant gloves, ensuring that they provide the necessary protection against hazardous chemicals. Understanding the importance of permeation testing helps maintain a safe working environment, protecting workers from chemical exposure and its associated risks.
Dive into the permeation guide of DPL, which provides detailed information on the performance of gloves against specific chemicals, aiding you in making informed decisions.
