ASTM F1671 / F1671M-13. 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 and/or 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.

Test not accredited in our laboratory.

The test method described in these standards evaluates the efficacy of materials used in the manufacture of protective clothing against bloodborne pathogens using a surrogate virus suspended in a liquid, simulating the conditions of continuous contact in a sanitary environment. Its objective is to evaluate samples of finished articles of protective clothing and the identification of possible candidate materials for protective clothing. This method is not effective for testing protective clothing materials that are internally coated with a thick coating that can absorb liquid containing the test virus.

Health professionals who treat and care for patients can be exposed to biological fluids capable of transmitting diseases. These diseases can be caused by a wide variety of microorganisms and can pose significant risks to health and life. This situation is especially important in the case of blood-borne viruses, such as the hepatitis B virus (HBV), the hepatitis C virus (HCV) or the human immunodeficiency virus (HIV). To protect themselves from infectious agents transmitted by blood, health personnel should wear protective clothing made of materials that prevent microbes or viruses from passing through. These protective garments can be, for example, gloves, aprons, masks, hoods, or boots, among others.

The test method described by the ASTM F1671 and ISO 16604 standards is specifically designed to simulate the penetration of hepatitis B virus, hepatitis C virus, and human immunodeficiency virus, and it is considered by extension that, if it resists penetration by these virus, it will also resist penetration by larger microorganisms, such as bacteria. To carry out the method, the test tubes of the materials are exposed to a nutrient broth containing the Phi-X174 bacteriophage virus, as a surrogate virus due to its characteristics similar in size and shape to the hepatitis C virus, and by extension to the hepatitis C virus. hepatitis B and human immunodeficiency (these viruses are not used because they are difficult to grow in laboratories).

For homogeneous or uniform samples, 3 test square pieces of between 70 and 75 mm2 must be evaluated. An additional 3 test tubes should be used to assess the compatibility of the material with the test microorganism, i.e. whether it contains substances that are inhibitory, retain or dry out the test microorganism and may lead to misinterpretation of test results. the proof. If a sample of protective clothing has different materials or thicknesses at different locations, pieces from each location should be tested. If it is desired to declare that the seams of a protective clothing offer the same protection as the base material, additional specimens containing the seams must be tested. The material used in the protective garment will pass or fail the test, depending on whether it resists (does not penetrate) or allows (penetrates) penetration by the Phi-X174 bacteriophage. The method is evaluated by two procedures: a) visual observation of the possible penetration of the liquid in suspension through the material, and b) detection of the virus on the surface opposite to that on which the material under study was exposed to the suspension. viral, even if no fluid was observed on the opposite side of the exposure. Any evidence, visual or virological of penetration, will indicate the inability of the material to resist penetration.

It must be taken into account if the protection material is going to be subjected to physical, chemical or thermal effects, which could negatively influence the behavior of the material (storage conditions, washing and sterilization of reusable materials, pre-wetting in alcohol, etc.). In the event that it can occur, the tests must be carried out after adequate preconditioning, representative of the expected conditions of use (physical, chemical or thermal conditions that may deteriorate it). The manufacturer must indicate the possibility that the tested material may be altered by heat treatment (moist sterilization), so as not to do so in the event that it may be altered. In the event that non-sterile material is used, the test will include the corresponding controls to exclude the presence of the bacteriophage in the evaluated materials.

The test is carried out exposing the specimens for a determined time and under a selected pressure, according to the ASTM F1671 or ISO 16604 standards:

For ASTM F1671 / F1671M-13 standard:

Select between: 1) procedure A (without retaining screen); 2) procedure B (with retaining  screen). The retaining screen (procedure B) must be selected for the evaluation of extensible or elastomeric materials.

For ISO 16604: 2004 standard:

  1. For materials and components in critical areas, that seek to limit exposure in situations involving the presence of a large amount of blood or body fluids in direct contact with liquids, pressure and inclination: 1) procedure A (without retaining screen); 2) procedure B (with retaining screen). 
  1. For critical area materials and components seeking to limit exposure in situations involving the presence of blood or body fluids and different possible levels of contact pressure. A selection must be made of the level of protection required, based on an analysis of the task and the anticipated degree of exposure: 1) procedure C (no retaining screen); 2) procedure D (with retaining screen). In case of selecting procedure C or D, the client must indicate the pressure at which the test must be carried out (1.75 KPa, 3.5 KPa, 7 KPa, 14 KPa or 20 KPa), based on the level of protection required. 

Procedures B and D employing a retaining shield should be selected for stretchable elastomeric materials.

This test method is normally performed after the test material has been tested for resistance to penetration by synthetic blood in accordance with ASTM F1670 or ISO 16603:2004, to confirm that although there is no visual penetration, no there is penetration of the bacteriophage. For procedures C and D, the highest pressure that did not show visual penetration in the test performed according to ISO 16604:2004 can be used for the test.