Selecting The Right Protective Clothing
For The Job

By Beth Hohl, Manager
Marketing and R&D
Kimberly-Clark Safety Division

Choosing the most appropriate protective apparel is a job in itself. With differing standards and guidelines, changing regulations, and a checklist of criteria including design, fit and cost, there’s a lot to consider. Of course, the primary responsibility of protective clothing is to protect the wearer—the critical factor in selecting proper apparel.

Risk Assessment Is the First Step
Safety professionals and their employers must, at all times, identify and understand the potential hazards workers may be exposed to and properly train them in selecting and wearing the appropriate apparel.

The first step in choosing the right protective clothing for the job is to identify the substances (particulates, liquids and gases) present in the work site as well as the hazards associated with these substances (i.e., dermal toxicity, reactivity, etc.). A survey of the work site must be completed listing physical or environmental hazards, such as sharp instruments, rough surfaces or machinery. Also, make a list of who will be wearing the clothing, the work that person will do, and what equipment will be used.

Once this task has been accomplished, determine the potential hazard exposure for each worker task. Ask the following questions to determine if there is anything specific to the worker task(s) that will require special protection:

• • What state will the hazardous substance be in (solid, liquid, or gas)?
  • What is the route of potential exposure (respiratory, dermal, or ingestion)?
  • Is exposure expected?
  • What is the frequency and duration of exposure?
  • What are the expected short- and long-term physical outcomes if exposure occurs?
  • What engineering changes can be made to eliminate or minimize the hazard?
  • Will all machinery be properly guarded?
  • What changes can be made to worker tasks to eliminate or minimize the hazard?

Once the task is engineered as safely as possible, it is time to turn to protective apparel. Protective clothing should be evaluated based on its fabric, seam construction, and overall design, sizing and fit.

Fabric Selection That Doesn’t Sacrifice Comfort
In general, the nature of the hazard will guide you to the appropriate clothing. Breathability and comfort of the garment are also critical factors, especially when trying to prevent heat stress. Keep in mind that when workers are more comfortable, they’re more productive. With today’s advances in materials and designs, there’s no need to sacrifice comfort for safety.

For tasks involving non-hazardous substances where keeping clean is most important, lightweight, breathable and durable fabrics will serve the purpose. When working with non-hazardous, particulate substances like dirt, sand, and grime, you need to make sure the fabric demonstrates adequate particulate hold-out properties. The key here is to find a fabric that resists particulates from the outside while allowing moisture, vapor and air to pass through for added comfort. In these situations, spunbond/meltblown/spunbond laminates have proven to provide an excellent balance of comfort and protection.

Situations where there is non-hazardous liquid splash or mists, such as water, oil, or detergents, call for a fabric with liquid resistance. Look for garments with outer layers constructed of a cloth-like, yet tough and abrasion-resistant spun bond polypropylene. Middle layers made of a breathable microporous film offer resistance to many non-hazardous liquids and particulates without compromising comfort. Garments like this are often chosen for use in manufacturing plants, nuclear facilities, utilities, agricultural settings, fiber glass handling, plus pressure washing and cleaning applications.

The highest level of fabric protection is needed for hazardous liquid or vapor exposure. Special gas or vapor protective suits may be required where exposure to hazardous vapor or gas can occur. These suits have a construction in which not only the fabric needs to resist hazardous materials, but the suit also maintains 4-inch positive air pressure with up to a 20 percent drop in pressure after four minutes in a standard inflation test (ref. ASTM F1052). Since hazardous liquid or vapor exposure may pose a serious threat to health, the fabric used must demonstrate appropriate resistance to the chemicals handled in your workplace.

When choosing chemical protective apparel, both penetration and permeation testing of the fabric should be considered. Penetration is the flow of bulk liquid through a material, or through seams or closures. Penetration resistance of protective clothing materials is measured using ASTM F903, a standard test method that visually determines material barrier performance against liquid chemicals under conditions of continuous contact. Permeation is the process by which a chemical moves through protective clothing material on a molecular level. ASTM F739 provides a standard test method designed to measure the resistance of protective clothing materials to permeation by liquids or gaseous chemicals under condition of continuous contact.

It is important when looking at manufacturers’ permeation and penetration data to ask the following questions about reported results:

• • How recent is the data? Continual improvements in testing methods and detection may make recent testing more accurate.
  • How confident can you be in the data? More tests improve the accuracy of reported results. Repeated testing ensures that the results are representative of the current product performance.
  • How reliable is the data? Was the testing done by an independent laboratory? Are the results reviewed for accuracy?

Garment fabrics are available with anti-static treatments to reduce static build-up and the likelihood of discharge—a consideration for workers in sensitive manufacturing, electronics, aerospace, pharmaceutical, and research laboratory settings. In addition, some garments feature a "glazing" process, which ties down outer fibers for low-lint performance. These garments can be appropriate for critical painting and finishing jobs in which lint can cause defects.

Seam Construction
Seams on a garment are as important as the fabric, because they are the most vulnerable part of the garment. Look for garments with seams on the back instead of the front. This provides more protection up front, where it’s needed most.

Serged seams—a basic stitched seam—are most common in general protection apparel, where resistance to hazardous substances is not intended. Look for a three-thread overlap stitching for the strongest, most durable seam. A bound seam is reinforced with binding for strength and tear resistance. A taped seam is serged, then reinforced with a film tape designed to be resistant to water and many liquid chemicals. Serged and taped seams are most often found in liquid chemical protection garments.

The Right Design and Sizing Helps Ensure Effective Use
Lastly, evaluate the garment’s design. If the exposure potential is low, risk may be isolated to specific body areas. In this case, all you may need are sleeve protectors or an apron. However, for moderate to high risks, full-body garments may be necessary.

Consider the combination of protective apparel and equipment that will be needed. Look at the garment’s hood, sleeves and cuffs to make sure that they work with other required equipment such as respirators, gloves and footwear.

Sizing and cut are also critical. Remember, if the garment doesn’t fit, the apparel itself may become a hazard. Look for a generous cut, especially across the shoulders, body and key stress areas like the crotch. In addition to enhancing comfort, a fuller cut helps to reduce pulls, tears and ripouts—protecting workers from an unplanned exposure, and ultimately reducing the number of garments used. An elastic waist can act as a belt for a better fit. A concealed zipper offers added strikethrough protection, and a longer zipper on coveralls will make them easier to pull on and off.

Getting The Best From Your Garments
Remember that protective garments won’t provide the required protection once they’re damaged. Garments should be replaced immediately if ripped, torn, abraded, punctured or if wear is observed in the outer layer of the material. Many protective garments are not flame resistant, so keep them away from sparks, flames, and explosive environments.

As a final note, keep in mind that the guidelines outlined above do not cover all considerations that must be made as part of a complete risk assessment. People involved in selecting protective apparel must be adequately trained and have a thorough understanding of workplace hazards and the selection of personal protective equipment.