ASTM F739-20 Standard Test Method for Permeability of Liquids and Gases through Protective Clothing Materials under Continuous Contact Conditions

The standard "ASTM F739-20 Standard Test Method for Permeation of Liquids and Gases through Protective Clothing Materials under Continuous Contact" published by the American Society for Testing and Materials (ASTM) describes a test method for measuring the permeation of liquids and gases through protective clothing materials under Continuous Contact. This test method is intended for use when the test chemical is a gas or liquid and the liquid is volatile (i.e. has a vapor pressure greater than 25 mm of mercury at 1 degrees) or dissolved in water or another liquid that does not interact with the clothing material.

For the purposes of this standard, the following terms and definitions apply:

• Analytical technique refers to a procedure by which the concentration of a test chemical in a collection medium is determined quantitatively. These techniques are generally specific to individual chemical and collection medium combinations. Applicable techniques include, but are not limited to: flame ionization, photo ionization, electrochemical, ultraviolet and infrared spectrophotometry, gas and liquid chromatography, colorimetry, spot length detector tubes, and radionuclide labeling and detection counting.
• Breakthrough detection time refers to the elapsed time measured from the first exposure to the test chemical to the sampling time immediately preceding the sampling time at which the test chemical was first detected. Breakthrough detection time depends on the sensitivity of the method.
• Closed circuit refers to a test mode in which there is no change in the volume of the collection medium other than sampling.
• Collection medium refers to the liquid, gas, or solid that absorbs, adsorbs, dissolves, suspends, or otherwise captures the test chemical and does not affect the permeability being measured.
• Cumulative permeation is the total mass of chemical that permeates a given area of ​​protective clothing material over a given period of time from the moment the material first comes into contact with the test chemical.
• Degradation refers to a detrimental change in one or more properties of a material. For protective clothing materials, changes in physical properties are usually of most concern.
• The minimum detectable mass permeated is the smallest mass of test chemical that can be detected by the full permeation test system.

This test method is normally used to evaluate flat samples of finished protective clothing and candidate materials for protective clothing products. Finished protective clothing products include gloves, sleeves, aprons, suits, coveralls, hoods, boots, respirators, and the like. The term “finished product samples” includes the usual continuous areas of protective clothing as well as the stitched or other interrupted areas. The seams selected for testing are representative of the seams used in the basic construction of the protective clothing product and generally include both the base material and the seams where the base material is joined to other types of materials.

Permeation detection time, standardized permeation time, permeation rate, and cumulative permeation are key measures of a clothing material's effectiveness as a barrier to a test chemical. Such information is used to compare clothing materials in the process of selecting clothing for protection from hazardous chemicals. Long permeation detection times, long standard permeation detection times, low cumulative permeation rates, and low permeation rates are characteristics of barrier materials that are more effective than materials with higher permeation properties.

Essentially, different chemicals interact with materials in different ways. What works for one chemical may degrade rapidly for another. ASTM F739-20 provides a standard procedure for testing this. It is important to know how long it takes for a chemical to migrate through a material. This is especially important when determining how long someone can safely wear personal protective equipment in a hazardous environment.

Without this testing, workers may unknowingly wear gloves, clothing, or other personal protective equipment that appear protective but allow hazardous chemicals to pass through, which can lead to chemical burns, poisoning, or chronic health effects. The ASTM F739-20 standard test method creates a controlled, reproducible laboratory method that manufacturers and safety professionals can trust. Many safety regulations (OSHA, NIOSH, and the like) require employers to select personal protective equipment based on tested and documented performance, and ASTM F739-20 chemical permeation testing is a frequently referenced standard.

Our organization, which has been trying to support businesses from every sector with its testing, measurement, analysis and evaluation studies carried out in a wide range for years, has a strong staff that closely follows the developments in the world in the field of science and technology and constantly improves itself. In this context, testing services are also provided to businesses in accordance with the standard "ASTM F739-20 Standard test method for permeability of liquids and gases through protective clothing materials under continuous contact conditions".