When choosing a glove for protection against viruses like the one that causes COVID-19, it’s important to know which regulatory standards exist to help ensure proper protection.
In the European Union, the EN ISO 374:2016 standard measures the ability of gloves to protect users against dangerous chemicals and micro-organisms. Part 5 of the EN ISO 374 standard outlines the terminology and performance requirements for micro-organisms risks (including viruses). Gloves featuring the EN ISO 374-5 VIRUS pictogram on packaging are proven to prevent the penetration of viruses through the glove material when tested in accordance with ISO 16604*.
In North America, the ability of gloves to protect against micro-organisms is defined by ASTM F 1671, a similar test to ISO 16604, whereby a sample of glove material is placed in a test cell with a bacteriophage under pressure one side. The glove is only confirmed as protective against viruses if there is zero penetration of bacteriophage into the other side of the test cell.
*ISO 16604:2004: Clothing for protection against contact with blood and body fluids - Determination of resistance of protective clothing materials to penetration by blood-borne pathogens - Test method using Phi-X 174 bacteriophage.
Protective gloves against micro-organisms
In the European Union, a glove claiming to offer a level of chemical protection must comply with the new EN ISO 374 standard. The standard consists of five parts, Part 2: Determination of resistance to penetration, determines the gloves ability to resist the penetration of chemicals. Part 5 – EN ISO 374-5:2016 Terminology and performance requirements for micro-organisms risks, specifies the performance requirements for gloves that protect the user against micro-organisms. There are two classifications:
a. Protection against bacteria and fungi
b. Protection against viruses, bacteria and fungi
A glove claiming protection from bacteria and fungi must carry the following pictogram and warnings;
All gloves claiming micro-organism protection must have been penetration tested as outlined in Part 2 of the standard. Gloves claiming protection from viruses require additional penetration testing according to ISO 16604:2004 - Clothing for protection against contact with blood and body fluids — Determination of resistance of protective clothing materials to penetration by blood-borne pathogens — Test method using Phi-X174 bacteriophage. The detection of any penetration constitutes a test failure. A glove claiming protection from virus, bacteria and fungi must carry the following pictogram and warnings;
In North America, gloves must pass ASTM F 1671 - Standard Test Method for Resistance of Materials Used in Protective Clothing to Penetration by Blood-Borne Pathogens Using Phi-X174 Bacteriophage Penetration as a Test System.
This test method is based on Test Method F903 used to evaluate the barrier effectiveness against penetration of liquids through materials, seams, closures or other planar assemblies used in protective clothing and specimens from finished protective clothing. Finished items of protective clothing include gloves, arm protectors, aprons, coveralls, suits, hoods and boots. Body fluids penetrating protective clothing materials are likely to carry microbiological contaminates and visual detection is not sensitive enough to detect minute amounts of liquid containing microorganisms. This test method is used to measure the resistance of materials used in protective clothing to penetration by blood-borne pathogens using a surrogate microbe under conditions of continuous liquid contact. Protective clothing material pass/fail determinations are based on the detection of viral penetration. Passing results indicate that no liquid penetration was observed over the duration of the test exposure.
What is Penetration, Permeation and Degradation?
Penetration
Penetration is the movement of a chemical and/or micro-organism through pinholes or other imperfections in a protective glove material at a non-molecular level.
Permeation
is the process by which a chemical dissolves and/or moves through a protective glove material on a molecular level.
Permeation can occur without damaging the material or by damaging the material by degrading it. Permeation is measured in the amount of time (minutes) it takes for a chemical to pass through the barrier at a determined permeation rate, which is referred to as Chemical Breakthrough Time; and the Permeation Rate which is the rate (volume over time) at which a chemical passes through the glove material.
Degradation
Sometimes chemical protective gloves can act as sponges, soaking up the liquids and holding them against the skin. This degrades the glove. Degradation is the change in one or more physical characteristics of a glove caused by contact with a chemical or bodily fluid. Indications of degradation are flaking, swelling, disintegration, embrittlement, colour change, dimensional change, appearance, hardening, softening, etc.
