Protective clothing: myths vs. facts
July 1, 2006
Choosing the most appropriate protective apparel can be quite a job. From assessing workplace risks and the likelihood for hazard exposures, to understanding how to apply performance data, garment ratings and international standards, the process may seem daunting to some. And, in fact, many people charged with apparel selection are operating under some fairly common misconceptions when it comes to matching the right protective garment to a specific work task.
Part of the problem stems from the lack of an established U.S. standard for protective apparel. While the National Fire Protection Association (NFPA) had previously addressed clothing worn for hazardous materials emergency response operations under its standards NFPA 1991, 1992 and 1993, no standard exists for the majority of chemical protective clothing worn by the U.S. workforce. And, although OSHA provides references to many applicable performance-based standards for certain types of PPE (i.e., eye and face protection), there is a void in its regulation with respect to the performance of protective clothing used within general industry. Even hazard-specific standards like 29 CFR 1910.1001, OSHAâ€™s General Industry Asbestos Standard and 29 CFR1910.1025, OSHAâ€™s General Industry Lead Standard still only call for the employer to provide â€œappropriateâ€ protective work clothing, â€œsuch as, but not limited to: coveralls or other similar full-body work clothing.â€
Common misperceptionsGiven the lack of uniform standards, itâ€™s no wonder garment users are confused. Following are several common misperceptions about how to evaluate and select protective garments, along with recommendations for avoiding further confusion.
MYTH: Permeation performance is the best and only criteria to evaluate in the selection of protective garments.
FACT: While permeation (the process by which a chemical moves through protective clothing on a molecular level) testing is important for garments that protect against unknown hazards or gaseous/vapor phase chemicals that represent the highest levels of respiratory and skin threats, many users of protective apparel simply do not need this high level of protection in everyday work situations. The result is a garment selection process that promotes over-protection, creating undue worker heat stress issues and productivity loss, as well as higher cost.
A second type of chemical barrier test â€” penetration testing â€” is more appropriate for testing chemical barrier when the chemical does not present a dermal vapor hazard as used, and splash exposure is anticipated. This scenario is far more likely in industrial settings. As a practical matter, many liquid chemicals will either evaporate quickly or run off the garment before having the chance to penetrate through to the skin underneath.
Dry particulate hold-out is another important criterion. Although no related industry-standard test currently exists, all major fabric and garment suppliers should have data measuring the permeability of the material to a variety of different size particulates.
MYTH: Itâ€™s better to over-protect than under-protect.
FACT: Both over-protection and under-protection have serious ramifications. Over-protection may lead to immediate problems such as wearer discomfort due to heat stress and result in non-compliance with wearing protocols. Under-protection may lead to chronic health problems down the road â€” after years of low-level exposure to certain hazardous substances. The goal is to find the best protection that offers the greatest wearer comfort possible based on the realities of the risk assessment and hazards analysis.
MYTH: The hazardous chemicals in the environment should drive garment selection decisions.
FACT: While identifying the hazardous chemicals and substances in the work environment is a key part of the hazard analysis process, narrowing apparel selection to just looking for a >480 minutes break-through time for a specific chemical leaves many options unexplored. The entire process of hazards analysis and risk assessment influences protective garment selection. The details of the application and a realistic understanding of the likelihood for exposure to the chemical are just as important as the chemical itself.
For example, there is a great deal of difference in the PPE required for a worker exposed to a quart of acetone in a well-ventilated room compared with one who is exposed to a large vat of acetone in an enclosed space. Similarly, if a workerâ€™s daily job involves cleaning parts with a solvent, exposure to that solvent is likely and usually controlled. It is an expected part of the job. However, a chemical pipe burst during a repair operation would be considered less likely to happen, but would be potentially more severe in terms of the consequences and may require a greater degree of protection. The protective equipment selected should be adjusted to meet the practical demands of the task.
MYTH: The best way to protect workers against hazardous substances is via a full-body coverall.
FACT: As stated previously, not all exposure scenarios will be the same. In some cases, such as with incidental splashes of chemicals to the front of the body, a full-body, chemical barrier coverall would be over-protective and costly. For example, if a wearer, as part of his job, needs to momentarily stop applying a dilute solution to mix additional chemical, he may only need to add an apron and sleeve protectors with gloves to gain adequate protection from the chemical concentrate. Climbing in and out of a full-body chemical coverall may not be practical and may deter compliance. Neither would it be practical to have the wearer in full-body coverage for the majority of the day while performing the dilute spraying application when higher level chemical protection is not fully required.
MYTH: Once a worker has exited a hazardous area, the need for protection is over.
FACT: Decontamination practices are often overlooked due to the focus on compliance during use. A common mistake is to wear respirators with straps on the outside of a protective hood. This is primarily done to avoid the discomfort of the respirator straps against the head. This practice makes it virtually impossible to remove contaminated clothing before removing respiratory protection; a respirator may be needed to protect the wearer from breathing in particles that may dislodge from the garment while the coverall is coming off.
Equal care should be taken to both properly enter and fit a coverall and to remove and decontaminate when the task is complete.
MYTH: One microporous film garment is the same as all the others.
FACT: Not every garment â€” even if made with the same type of material â€” will perform the same. The assumption that less expensive garments perform the same because they purport to be made of the same material type can be a dangerous error. Nonwoven processes are highly variable, and protective factors can be compromised even when visual cues (holes, tears, etc.) are not present. The end-user should demand performance data to demonstrate barrier and durability characteristics as part of the qualification process for any new product.