Considerations for Selecting Protective Clothing used in Healthcare
Healthcare workers wear protective clothing (e.g., surgical gowns, isolation gowns, and coveralls) to protect both patients and themselves from the transfer of microorganisms by blood and body fluids.
Selecting Protective Clothing
Barrier Properties of Protective Clothing
A microorganism’s movement through protective clothing materials depends upon several factors, including the following:
- Physical and chemical properties of the fabric: Includes factors such as thickness pore size, and repellency
- Shape, size, and other characteristics of the microorganisms: Includes factors such as morphology, motility, and adaptation to environmental extremes
- Characteristics of the carriers: Includes factors such as surface tension, volume, and viscosity
- External factors: Includes factors such as physical, chemical, and thermal stresses
Several different microorganisms have been found in healthcare settings, including bacteria, viruses, and some fungi.
Microorganisms are transported by carriers such as body fluids, sloughed skin cells, lint, dust, and respiratory droplets.
Design of protective clothing: gown vs coverall
Employers should consider the garment design as part of their selection process. Unfortunately, no clinical studies have been done to compare the efficacy of gowns vs. coveralls. Both have been used effectively by healthcare workers in clinical settings during patient care.
While the material and seam barrier properties are essential for defining protection, the coverage provided by the material used in the garment design, as well as certain features including closures, will greatly affect protection.
For example, a coverall with a front zipper closure could result in the compromise of barrier protection if the ordinary cloth and plastic zipper used in its construction is not covered with a flap of barrier material that can be sealed to the garment.
Similarly, most of the surgical gowns rated for high levels of barrier protection may include the high-performance barrier materials in only certain portions of the gown (sleeves and front panel). This is especially important when contact from hazardous/contaminated fluids can come from multiple directions.
In general, there is a significant difference between the design of traditional coveralls and isolation/surgical gowns.
- Traditional coveralls: Provide 360-degree protection because they are designed to cover the whole body, including back and lower legs and sometimes head and feet as well.
- Surgical/isolation gowns: do not provide continuous whole-body protection (e.g., possible openings in the back, coverage to the mid-calf only)
- Gowns: are relatively easier to put on and, in particular, to take off. They are generally more familiar to healthcare workers and hence more likely to be used and removed correctly.
During patient care, the risk of the anticipated exposure is typically in the area of front chest and sleeves, thus gowns are used frequently in health care.
- Coveralls: The level of heat stress generated due to the added layer of clothing is also expected to be less for gowns than coveralls due to several reasons, which include the openings in the design of gowns and the total area covered by the fabric.
For gowns, it is important to have sufficient overlap of the fabric so that it wraps around the body to cover the back (ensuring that if the wearer squats or sits down, the gown still protects the back area of the body).
Review Protective Clothing Manufacturers Data/ Information
Gown and coverall manufacturers should be consulted before selections are made to:
- Review both fabric and garment specifications (including type, strength, and barrier testing results of seams) of the protective clothing in consideration;
- See if the considered protective clothing is suitable for use in a medical setting;
- Determine protective clothing design features, including areas of protective coverage and features that impact its ability to be effectively integrated with other forms of PPE;
- Determine if a range of sizes to fit all staff is available;
- Understand the ease of use (including ease of wear and removal without self-contamination); and
- Review all available information on protective clothing including potential limitations, availability, and practicality.
Current Healthcare Protective Clothing Standards and Specifications
Several fluid-resistant and impermeable protective clothing options are available in the marketplace for healthcare workers. These include isolation gowns, surgical gowns, and coveralls.
When selecting the most appropriate protective clothing, employers should consider all of the available information on recommended protective clothing, including the potential limitations. Employers should consult protective clothing manufacturers as needed in regards to availability and practicality for their facilities.
A key step in this process is to understand the relevant standards and test methods. Descriptive information about each standard is provided in the body of this document.
Standard Test Methods to Measure Blood and viral penetration resistant
When the transmission route is defined as “direct contact transmission,” employers should consider gowns and coveralls that demonstrate resistance to synthetic blood, as well as the passage of the virus. Standard test methods can be used to evaluate the resistance of fabrics or seams/closures to synthetic blood penetration and viral penetration.
- Synthetic Blood Penetration – ASTM F1670/ ISO 16603
- Viral Penetration: ASTM F1671/ ISO 16604
ASTM F1670 and ISO 16603 are “screening-tests” that evaluate the resistance of a material to synthetic blood penetration
Performance requirements for protective clothing
This technical report is structured to be as broad as possible in listing multiple test methods with minimum performance requirements in order to maximize the potential that an employer will find appropriate data from different manufacturers.
However, it is important to note that different test methods, while similar, do not yield the same absolute results due to differences in test equipment, conditions, and procedures.
These particular methods/standards have been selected because they are broadly used in the industry and current international protective clothing classification standards to describe the performance levels provided by garments and to differentiate the protection levels provided.
Employers should be aware that garments qualifying under different standard methods may in fact provide different levels of protection. Limited information is available to compare different products using these test methods.
Standards are available to define the performance requirements for clothing or clothing materials used to protect against infectious agents. ANSI/AAMI PB70external icon, EN 13795, EN 14126, and NFPA 1999 are examples of standards frequently used in the United States and Europe.
ANSI/AAMI PB70 is used to classify the garments used in the healthcare industry, such as surgical and isolation gowns.
Typically, EN 14126 is used for protective coveralls, and EN 13795 is used for surgical gowns. NFPA 1999-2013 is primarily intended for emergency medical first responders, but its scope also covers medical first receivers.
Comparison of the Test methods and classification standards for gowns and coveralls
Similarly, for coveralls, it is difficult to compare test methods and performance specifications directly.
In Europe, the EN 14126 standard typically is used to evaluate and classify coveralls used to protect from infectious agents, and EN 13795 is used to evaluate and classify surgical gowns.
Unlike surgical or isolation gowns (ANSI/AAMI PB70), there is no widely used classification standard in the United States. Coveralls with materials and seams tested against ASTM 1671 are specified in NFPA 1999–2013, Standard on Protective Clothing for Emergency Medical Operations.
This standard establishes minimum performance requirements for single-use emergency medical garments, multiple-use emergency medical garments, and other PPE for protection
Source: CDC ->NIOSH ->NPPTL