Material Selection, Isolation Standard and Testing Requirements of Medical Isolation Clothing

Medical isolation gowns and protective clothing  are made of polypropylene non-woven fabric, which is SMS non-woven fabric (S is spunbond layer, M is meltblown layer). Because of the shortage of medical equipment, some doctors use polypropylene raincoats. Do these yellow, white, blue, and dark blue protective suits, isolation gowns, and surgical gowns have corresponding standards? Are the material requirements the same? Following discussions on these medical supplies are from the perspective of polymer materials.

1. Material selection of medical isolation gowns

For any piece of medical isolation gowns, after the SMS spunbond fabric and meltblown fabric are compounded, it is not to be made into gowns immediately, but to be post-processed to meet the requirements of the three antibodies: water resistance, alcohol resistance, and blood resistance. The treating liquid is generally a fluorine-based material.

After the processing is completed, gowns are made and then disinfected. Common medical disinfection way includes high-temperature steam sterilization, ethylene oxide sterilization and radiation sterilization. The radiation sterilization enjoys the best effect.

Therefore, some articles mention the use of electron beam for disinfection and sterilization. What needs to be noticed here is that radiation sterilization is effective which eliminates bacteria, but the polypropylene is also eliminated. That is, the performance of the non-woven fabric is also attenuated after radiation. If the epidemic has not occurred for several years later, the surgical gown was probably crushed and degraded.

2. Isolation standards for medical isolation gowns

In addition to the difference in color, the barrier requirements are definitely different. According to the AAMI definition, medical isolation gowns is a type of protective clothing. In the case of patient isolation, it is used to protect medical personnel and patients from infection of microbes and body fluids. Protective clothing is mainly designed to isolate all or part of the body from potential dangers, or to isolate the external environment from infection for the wearer.

3. Testing requirements for medical isolation gowns

Spray test: observe how much water will penetrate after the non-woven fabric is sprayed with water. According to the standard placement method of the sample, spray deionized water on the surface of the fabric and test the weight of deionized water absorbed by the filter paper under the fabric through the fabric.

Hydrostatic pressure test: observe how much pressure the non-woven fabric is taken, water droplets will appear. The test refers to applying a pressure of 60 mbar/min on a test area of 100 square centimeters to test the product's ability to block water.

The AAMI standard has extremely high requirements on non-woven fabrics. The non-woven fabrics we mentioned are composed of two kinds of polypropylene fibers. The fibers may leak. If we put the film in, the problem of permeation is completely solved. Therefore, in the highly demanding AAMI Level 4 medical isolation gowns, a hydrophilic and moisture-permeable film with air permeability would be used.