You are what you wear." This sartorial adage is especially true when it comes to protective apparel. That's because the safety of at-risk employees depends on not only the performance of their protective apparel but also its wearability. To achieve necessary protection, workers must be willing and able to wear the proper clothing when performing their duties.
Characteristics that encourage workers to wear garments at the proper time and in the proper way should be considered key criteria when selecting protective clothing inventory. While employers traditionally focus on barrier performance, durability and permeability when selecting garments, their responsibilities in providing workers with protection extend beyond supplying apparel with those basic performance characteristics.
For example, employers must be responsible for selecting protective apparel that meets the specific workplace hazard, for training employees in its proper use, for documenting that employees understand how to select and dispose of their clothing, and for retraining and retesting those employees who fail to use their clothing properly. Retraining and retesting also are required whenever workplace hazards change significantly. The employer's success in meeting these requirements can be influenced greatly by the "wearability characteristics" of garments made available to the work force.
Nine Elements of Wearability
What are some of the wearability characteristics to look for when evaluating personal protective equipment (PPE)? While certain requirements will depend on the type of breathing apparatus and other special features of the total protective ensemble, nine attributes are important in all applications that involve garments made from protective fabrics. Each of these characteristics will have an influence on workers' attitudes toward protective apparel and how they will use the garments provided for their safety.
1. Reliable Barrier Protection and Durability
Can the wearer be confident in the garment's ability to protect against all workplace hazards and stand up under rugged job conditions?
Employees must feel safe and secure in the apparel provided for their use. Employers should select protective garments with documented barrier properties. This information is available from garment manufacturers and should be retained by the employer with other PPE selection documentation. (Caution: Most barrier tests are performed on pristine materials; manufacturers also should supply barrier data on materials that have been abraded and flexed as they will be when in use.)
Employers also must determine if the barrier tests are relevant to the workplace hazard involved. For example, barrier tests conducted with particles greater than five microns may not be meaningful in selecting many garments. Particles of this size settle 20 times faster than one-micron particles and do not remain airborne for long. Barrier tests using one-micron particles are preferred because particles of this smaller size remain in the air for extended periods and are more likely to penetrate the garment and to be inhaled deeply into the lungs.
2. Proper Fit
Does the garment allow the wearer to perform the job function in the normal manner without added difficulty? Does it allow a full range of motion without binding or risk of tearing?
When it comes to selecting protective apparel, there is no one-size-fits-all solution. A garment that is too large is just as unacceptable as one that is too small. Subpart I of OSHA's standard for personal protective apparel, 29 CFR 1910.132, requires employers to provide workers with apparel that fits properly. Sizing charts are helpful in issuing clothing, but it is important for employees to try on the garments they will wear to ensure a good fit and full range of motion. This is because the size designations for protective garments may not be the same as those for consumer apparel (e.g., jackets and sweatshirts).
In addition, not all garment manufacturers use the same sizing standards. Without uniform standards, garment manufacturers are free to change sizes and dimensions arbitrarily. To help achieve uniformity, DuPont requires manufacturers of Tyvek* garments to follow American National Standards Institute minimum sizing standards and audits garments made of Tyvek to ensure that standards are met.
3. Ease of Care, Maintenance and Repair
Can the wearer care for garments with minimal effort?
Simplified care is one of the major advantages of limited-use clothing materials. These garments are designed and priced to be used only once or a limited number of times and then disposed of. They require no special care by the wearer other than proper storage. On the other hand, protective apparel that is designed to be reused must be cleaned and inspected after each use. Damaged items must be repaired or retired from use. Repairing reusable garments often requires that the items be thoroughly decontaminated and returned to the manufacturer. In some applications, only the manufacturer can determine if the garment has been damaged beyond repair.
The key metric in choosing between limited-use and reusable clothing is usually cost per use. However, a garment's care requirements must be included in making such calculations because the costs of garment maintenance, repair and storage can be significant. What's more, care requirements influence the amount of effort that employees must expend to wear their garments in the correct manner. Thus, care requirements become a cost and wearability issue.
4. Flexibility and Lightweight
Is the apparel supple and pliant? Does it allow the wearer maximum freedom of movement? Is it light in weight?
Minimum weight and maximum flexibility are important in a protective garment because they affect the wearer's range of motion and degree of job fatigue. While lightweight, limited-use protective apparel offers significant advantages over reusable garments, lightweight fabrics also must be strong enough to withstand the rigors of the workplace. For example, Tychem BR, a new material developed by DuPont for protection against hazardous chemicals, is an excellent example of a high-barrier, high-strength fabric that excels in this important wearability characteristic.
5. Comfort and Heat Stress
Will the wearer find the garment comfortable -- both aesthetically and physiologically? Does the garment allow sufficient air flow to prevent heat stress?
To the employee, the aesthetic comfort of a protective garment (how it looks and feels) can be just as important as its physiological comfort (whether it contributes to heat stress). Although both affect wearability, it is important to remember: Never sacrifice barrier to obtain comfort.
Aesthetic comfort. There is a concern that aesthetically unpleasant apparel will not be worn properly. Aesthetic comfort is a function of personal preference, plus other complex factors, and can be difficult to measure accurately. Carefully controlled experiments have been designed to determine aesthetic comfort qualities of protective garments. Because of the cost and effort involved in these tests, however, evaluations are usually based on anecdotal comparisons.
Physiological comfort. More important to the wearability issue is the employee's physiological comfort when working in a protective garment. (Physiological comfort is directly tied to heat stress.)
All clothing has an impact on the body's temperature mechanism. By its nature, protective clothing can be an added barrier to natural cooling. In hot, humid situations where the worker is sweating profusely, body cooling depends on the rate at which moisture is removed from the space between the skin and the clothing. Recent studies by DuPont comparing a wide range of limited-use garments have demonstrated that the mass transport of humid air, or "air flow," through the fabric is the key to heat stress and physiological comfort of a garment. (Some manufacturers erroneously claim that the comfort of barrier garments is controlled by the rate that water vapor diffuses through the protective fabric material. This diffusion measurement is called moisture vapor transmission rate.)
6. Ruggedness of Construction
Is the garment well-made? Is there sufficient material at key stress points? Has quality stitching been used?
In addition to quality fabric and proper seam construction, garments must be properly styled and correctly cut to accommodate the full range of activities involved in the job task.
7. Donning and Doffing Characteristics
Is the garment easy to put on (don) and take off (doff)? Will doffing contribute to contamination of hair, skin or clothing?
Proper donning and doffing of protective equipment, including apparel, is a requirement of Subpart I of OSHA standard 29 CFR 1910. OSHA inspectors have issued citations for failure to train workers in correct procedures. Proper doffing methods should focus on removing apparel without contaminating the wearer. For example, asbestos workers must be trained to remove garments while still wearing their respirators. Only after contaminated garments have been removed and properly contained are the workers free to exit to a noncontaminated area and remove their respirators. Degree of difficulty in performing the don/doff functions is an important wearability issue and should be considered when selecting all items of protective apparel.
8. Ease of Cleaning, Disposal and Recycling
Can the wearer dispose of used garments without extra work? Is there a potential "take-home" problem? Can contaminated garments be discarded in an environmentally safe manner?
Any extra effort required of the employee to maintain and dispose of protective equipment may discourage proper use. Limited-use garments require little, if any, maintenance and score high in this regard. Reusable garments that become contaminated with hazardous materials should be laundered by the employer, not sent home with the employee. In fact, in several regulations, OSHA mandates that workers must not take contaminated protective clothing away from the workplace to be laundered. However, this has not eliminated the problem of transferring hazardous materials to the home environment.
The take-home problem also can result from other actions. When workers are exposed to hazardous materials in the workplace, there is always the concern that they will unknowingly take those contaminants into their car or home. For example, the employee's street clothes may become contaminated because the protective apparel provided is inadequate. If workers walk away from the job wearing contaminated personal clothing, they may contaminate their nonwork environment and inadvertently expose themselves, their family and their friends to hazards of the workplace. This is especially dangerous in situations where respirators are used in the workplace, because no employee drives home wearing a respirator for protection.
Even though these take-home exposures may be at a lower level, the hazard is real and must be considered a serious wearability issue. This problem has been documented in a recent National Institute for Occupational Safety and Health report to Congress, as well as in numerous industrial hygiene studies, including a recent article about beryllium contamination that appeared in the American Industrial Hygiene Journal.
9. Proper Garment Design
Ensuring that protective apparel is properly designed and made from the right materials may be the most important -- and most controversial -- of all wearability issues. Contrary to common practice in some firms, selecting the right fabric and the right style of garment for an application should not be the job of the purchasing agent. The selection of protective clothing is a critical safety and health decision that should be made by safety and industrial hygiene professionals.
What's more, it is unwise to allow the purchasing department to deviate from established apparel specifications and make substitutions based on claims that alternate products "meet the industry standard" or "are equal to the garments now in use." Garment design and materials of construction are critical to proper protection and the safety of employees. Decisions on this wearability issue should be made with care by qualified safety professionals.
When it comes to selecting apparel for at-risk workers, remember that "protection is in the wearing." By offering employees apparel that provides protection and good wearability characteristics, employers will encourage their workers to make optimum use of their safety wardrobe and achieve a higher level of personal protection.
James P. Zeigler, Ph.D., is a research associate in the Tyvek Business at the Spruance Plant in Richmond, Va. As such, he provides market support and product development for Tyvek Protective Apparel and Tychem chemical barrier fabrics. Zeigler has particular expertise in protective apparel research testing, protective apparel industry regulations and standards, weapons of mass destruction and more. He serves as chairman of the particulates subcommittee on the American Society for Testing and Materials Committee F23 on Protective Clothing and is a member of the National Fire Protection Association technical committees for Emergency Medical Services and Hazardous Materials Protective Clothing and Equipment.