The Right Suit for the Job

How can you evaluate the "appropriateness" of a specific garment? Review the performance of individual garments against two test ASTM methods.

• By Kimberly Dennis
• Apr 01, 2003

IN many occupations--even outside of hospitals and other health care environments--workers run the risk of being exposed to potentially hazardous bloodborne pathogens and bodily fluids. In fact, it is estimated that approximately 5.6 million workers in the United States are at risk of exposure to bloodborne pathogens, including 1.2 million non-health care workers. Laboratories, mortuaries, janitorial services, animal research facilities, laundries, emergency response, and crime scene cleanup are just a few of the non-health care work settings in which employees may be exposed to blood, bodily fluids, and bloodborne pathogens.

Employers and workers in these and other industries need to know how to evaluate protective apparel for protection against bloodborne and bodily fluid hazards. It's especially important to note that, just because a protective garment offers adequate resistance to certain liquids, one should not assume the garment will also protect against bloodborne pathogens.

What Are Bloodborne Pathogens?
The Occupational Safety and Health Administration defines bloodborne pathogens as "infectious materials in blood that can cause disease in humans, including hepatitis B and C and human immunodeficiency virus, or HIV." Workers exposed to these pathogens risk serious illness or death.

In addition to human blood, blood products, or blood components, other potentially infectious materials include human body fluids such as saliva; semen; vaginal secretions; cerebrospinal, synovial, pleural, pericardial, peritoneal, and amniotic fluids; any body fluids visibly contaminated with blood; unfixed human tissues or organs; HIV-containing cell or tissue cultures; and HIV- or HBV-containing culture mediums or other solutions.

Relevant Standards
Title 29 of the Code of Federal Regulations Section 1910.1030 contains the standards for what employers must do to protect workers whose jobs put them at a reasonable risk of coming into contact with blood and other potentially infectious materials. These should be reviewed and understood. The standards require employers to:

• Establish an exposure control plan to eliminate or minimize employee exposures.
• Use engineering controls to isolate or remove bloodborne pathogen hazards from the workplace.
• Enforce work practice controls to reduce the likelihood for exposure.
• Provide personal protective equipment such as gloves, gowns, and masks.
• Make Hepatitis B vaccinations available to employees.
• Provide post-exposure follow-up to workers who experience an exposure incident.
• Use labels and signs to communicate hazards.
• Provide information and training to employees on dangers, preventive practices, and post-exposure procedures.
• Maintain employee medical and training records.

CFR 1910.1030 states that "personal protective equipment will be considered 'appropriate' only if it does not permit blood or other potentially infectious materials to pass through to or reach the employee's work clothes, street clothes, undergarments, skin, eyes, mouth, or other mucous membranes under normal conditions of use and for the duration of time which the protective equipment will be used."

How can one evaluate the "appropriateness" of a specific garment? The American Society for Testing and Materials has developed two test methods to assess the effectiveness of materials used in protective clothing for protecting the wearer against contact with bodily fluids and bloodborne pathogens. Garment specifiers and purchasers should review the performance of individual protective garments against these two test methods.

ASTM F1670-98 is the Standard Test Method for Resistance of Materials used in Protective Clothing to Penetration by Synthetic Blood. It is intended to identify protective clothing material candidates for further testing according to a more rigorous procedure involving a surrogate for bloodborne pathogens. The more rigorous procedure is found in ASTM F1671-97b, the 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.

Both methods provide for penetration testing under conditions of continuous liquid contact. ASTM F1670-98 bases pass/fail determinations for protective clothing on visual detection of synthetic blood penetration, while ASTM F1671-97b bases pass/fail determinations on detection of viral penetration. Both test methods are based on ASTM's Test Method F903 for measuring the resistance of chemical protective clothing materials to penetration by liquids.

It is important to point out here the reliance on penetration resistance testing versus permeation resistance testing. Some garment manufacturers tout the chemical permeation resistance of their fabrics and garments while downplaying or ignoring penetration resistance. With bloodborne pathogens, penetration resistance is the key performance variable for determining both liquid splash and pathogen resistance because bloodborne pathogens are transmitted by the physical passage of liquid.

Protective Fabric Technology
In evaluating garments for their ability to protect against bloodborne pathogens, one can look toward the health care industry for direction. There, protection from blood and bodily fluids is a constant concern. Many health care professionals turn to gowns and drapes made of breathable-barrier film laminates, such as those comprised of microporous films, to provide a unique combination of comfort and protection.

Outside of traditional health care settings, one can easily find protective suits made of breathable-barrier film laminates, with a microporous film interior layer and outer layers made of a copolymer of polypropylene and polyethylene. The microporous film inner layer allows heat and sweat vapor to escape, yet protects against bloodborne pathogens, as well as sprays from many non-hazardous liquids and small particles. The relatively tough outer layers protect the film barrier from tearing and abrasion. This construction results in a good combination of durable comfort and protection.

The most crucial part of the microporous film laminate is the film layer itself. As the name implies, an interconnected network of micropores is formed in the film, which by tortuous path and size permits the transfer of moisture vapor (such as perspiration) while inhibiting the transfer of liquids and particulates. The transfer of heat and perspiration away from the skin and through the laminate itself enables the body to cool itself and helps the skin to feel drier. Because the microporous film itself is usually not very durable or cloth-like, it is typically laminated to at least one nonwoven layer or preferably to two layers, forming a sandwich with the film in the middle.

The fabric structure is ideal for surgical gowns because it keeps the surgeon safe from bloodborne pathogens while remaining breathable and comfortable throughout hot, grueling medical procedures such as those encountered in orthopedic surgery. It also is ideal for non-hazardous liquid and limited chemical protection, because its blood and bodily fluid resistance translate nicely into liquid barrier performance under pressure in industrial applications.

Garments made of flashspun polyethylene without a film laminate, on the other hand, may be assumed to provide adequate bloodborne protection, but in reality they do not. In fact, there are currently no flashspun polyethylene suits without films on the market that pass ASTM F1670/1671 testing.

Additional Factors
In addition to the fabric technology used in protective garments, the design or construction of the actual garment affects its ability to protect against bloodborne pathogens.

For example, a garment with seams in the back instead of the front provides more protection in primary exposure areas. A seam that is serged with overlap stitching, then reinforced with a film tape, will better resist penetration by blood and other liquids as compared with unsealed seams. Covered zippers also provide extra protection in splash situations.

A generously cut garment, with extra room in the seat and crotch, will provide for a fuller range of motion while reducing the pulls, tears, and ripouts that can compromise the protection the garment offers.

In conclusion, when workers run the risk of being exposed to bloodborne pathogens, it is wise to evaluate the protective garments they will be wearing against the appropriate ASTM test methods, while also considering the human comfort factors of garment fit and breathability.

This article originally appeared in the April 2003 issue of Occupational Health & Safety.