According to European standards, there are six basic types of protective clothing against chemical and microbiological hazards, including COVID-19. Based on the different groups of applications, these six types include: 1) gas-tight, 2) air-fed non-gas-tight suits, 3) suits against pressurized liquids, 4) suits against sprayed liquids, 5) suits against solid particles, and 6) suits offering limited protective performance liquid chemicals. With the exception of Type 5, the level of protection reduces from Type 1, which offers the highest level of protection, to Type 6, which offers the least protection.
Types 3 to 6 suits are normally worn with gloves, respirators, and protective boots, whereas Types 1 and 2 suits are full body suits incorporating protection for feet, hands, and face.
Table 1 delineates the details of each type, including the definition and symbol designated for the types.
Table 1. Definition of protective clothing types and their usages
Type 1 and Type 2
Type 1 protective clothing refers to completely enclosed protective gas-tight suits designed to protect against chemical contamination in the form of liquid or gas. Similarly, Type 2 protective clothing refers to non-gas tight suits that retain positive pressure to prevent the ingress of dust, liquids, and vapors.
Since Type 1 and Type 2 protective suits are designed for highly hostile environments, they are fully sealed, incorporating breathing apparatus, or an air line for air supply. They are used in highly hazardous industrial environments or by emergency responders. Figure 1 and Figure 2 are the images of Type 1 and Type 2 protective clothing.
Figure 1. Image of Type 1 Protective Clothing
Figure 2. Image of Type 2 Protective Clothing
Type 3, Type 4, Type 5, and Type 6
In general, the most commonly used protective suits are Type 3 through to Type 6. Type 3 and 4 suits are made from non-breathable and chemically resistant fabrics. Both Type 3 and Type 4 are designed to protect against liquid chemicals. However, Type 3 suits should be able to withstand a jet of liquid, whereas Type 4 suits are designed to withstand a high-pressure spray.
Since Type 3 protective clothing withstands strong directional jets of a liquid chemical during the test, it has sealed seams rather than stitched. The standards to meet Type 4 classification are similar to those for Type 3, but a lighter spray at a lower pressure is used to test the qualification for Type 4.
Type 5 suits are full-body protective items covering the trunk, arms, and legs, such as one-piece coveralls or two-piece suits, which can be with or without hoods, visors, and foot covers. Type 5 is tested to verify its resistance to dust and particles.
Specifically, the test for Type 5 includes exposure to a dry aerosol with a particle size of 0.6um. The test result should indicate that the inward leakage of the aerosol must be below a minimum threshold.
Like Type 3 and Type 4, Type 5 protective clothing also protects against light spray and splashes. However, it differs from Type 3 and Type 4 tests in that there is less volume of liquid sprayed and no build-up of liquid.
Type 6 suits, offering the lowest level of protection, are designed to protect against splashes and light sprays.
Therefore, Type 6 protective suits are suitable for environments where occasional splashes by liquids of relatively low toxicity are possible (e.g., paints). Figure 3 to Figure 6 are the images of Type 3 to 6 protective suits.
Figure 3. Image of Type 3 Protective Clothing
Figure 4. Image of Type 4 Protective Clothing
Figure 5. Image of Type 5 Protective Clothing
Figure 6. Image of Type 6 Protective Clothing