Chemical Splash

PENETRATION RESISTANCE

Penetration resistance testing evaluates if liquids physically penetrate materials using visual observation for detection. It is intended for use with liquid-splash, liquid-tight, EPA level B or C garments. The primary purpose is to keep liquids from contacting the wearer’s skin.

PERMEATION RESISTANCE

Permeation resistance testing measures the passage of chemicals (liquids and gases) through a material at a molecular level and requires sensitive analytical equipment to detect chemical breakthrough. It is intended for use with vapour-protective, gas-tight, EPA level A garments. The primary purpose is to isolate the wearer from a surrounding hazardous chemical environment.

ASTM F903 TEST METHOD

Standard Test Method for Resistance of Materials Used in Protective Clothing to Penetration by Liquids

PURPOSE

This test method provides a quantitative determination of the liquid barrier performance of protective clothing, clothing constructions and materials and is used to evaluate and compare the liquid penetration resistance of protective clothing and materials. 

SCOPE

This test method is used to test specimens of protective clothing and candidate materials and constructions to be used in protective clothing for resistance to visible penetration of liquids. In somes cases, significant amounts of hazardous materials will permeate specimens that pass this penetration test. The resistance to visible penetration of the test liquid is determined with the liquid in continuous contact with the normally outside surface of the test specimen. For more sensitive analysis of liquid permeation ASTM Test Method F739-99a is recommended (Test Method for Resistance of Protective Clothing Materials to Permeation by Liquid or Gases under Conditions of Continuous Contact).

KEY DEFINITIONS

Penetration - The movement of matter through closures, porous materials, seams and pinholes or other imperfections in protective clothing on a non-molecular level. Discussion - for this test method, the specific material is a liquid chemical (based on hazard analysis). 

Permeation - The process by which a chemical moves through protective clothing material on a molecular level. Discussion - permeation involves the following: (1) absorption of molecules of the chemical into the contacted (challenge side) surface of the material, (2) diffusion of the absorbed molecules in the material and (3) desorption of the molecules from the opposite (collection side) surface of the material.

Protective Clothing - A garment used for the purpose of isolating parts of the body from contact with a potential hazard.

TEST PROCEDURE C (TEST YIELDS PASS OR FAIL)

The test method evaluates the liquid penetration of a single layer or multiple layer material specimen from an item of protective clothing, that is, the base material of which the protective clothing item is made, a seam or a closure. Specimens may also be from a material intended for use in protective clothing. The test specimen is placed on a test apparatus designated as a 'Liquid Penetration Tester', which applies the chemical liquid of interest so that the liquid is in contact with the outside surface of the material specimen (challenge surface). 

The material specimen passes if the inside surface of the material specimen indicates no presence of liquid at the time selected for the test and the material specimen fails if the inside surface of the material specimen does indicate the presence of liquid prior to the time selected for the test. The time is noted when the first indication of liquid is observed.