Comparison of methods: determination of UV protection of clothing

Based on spectrophotometric measurements and mathematical calculations, the ultraviolet (UV) protection factor of a textile is determined in vitro. This technique is the most established test method for the determination of UV protection of a garment. However, the validity and practicality of the in vitro UV protection factor (UPF) determined in the laboratory has been a controversial issue with regard to its significance in the field. Several studies have verified the in vitro UPF by comparing it with various in vivo test protocols using solar-simulated radiation for the determination of the minimal erythema dose. The data inconsistency between these studies is certainly due to different methodology. Furthermore, UV dosimetry is a suitable method for quantifying UV transmission through a garment. Chemical dosimeters (e.g. polysulfone films) and biological UV detector films have been used in in vivo-simulated studies in the form of small portable badges monitoring solar UV transmittance through garments on manikins and mobile subjects. As sunlight consists to a considerable extent of diffuse radiation, which is more scattered and absorbed by the fabric than direct radiation, UPF values obtained by measurements in real exposure situations are usually higher than those obtained by conventional in vitro and in vivo testing with collimated radiation beams. Thus the discrepancy between laboratory-based testing and field-based measurements may be due to different radiation geometry of UV sources. Taken together, the in vitro method is the most practicable and inexpensive method for routine measurements of UPF, but dosimetry seems to be a highly useful method for determining the UPF in real exposure situations.

American standards for UV-protective textiles

During the last 3 years, three standard documents that pertain to the testing and labeling of UV-protective textile products have been published by the American Society for Testing and Materials (ASTM) and the American Association of Textile Chemists and Colorists (AATCC). The titles of these documents, which are available for purchase at www.astm.org and www.aatcc.org are: ASTM D 6544 "Standard Practice for the Preparation of Textiles Prior to UV Transmission Testing", AATCC 183 "Test Method for Transmittance or Blocking of Erythemally Weighted Ultraviolet Radiation Through Fabrics", and ASTM 6603 "Standard Guide to Labeling of UV-protective Textiles". This chapter summarizes the content of each document and shows how the documents are linked together to make a comprehensive plan for the testing and labeling of UV-protective textile products to be sold in the United States. It also describes the intended future work in the United States on UV-protective textile standards.

A historical review of barrier materials

When surgical gowns first were used, their primary purpose was to protect patients from members of the surgical team. In 1952, it was revealed that although the muslin the garments were made from may have been an effective barrier when dry, it lost barrier capability after it became wet. This disclosure triggered research to develop more satisfactory materials for this unique application. In the interim, the emergence of HIV was accompanied by the need to protect surgical team members from patients, and barrier effectiveness attained even greater importance. During the past 50 years, several attempts have been made to develop a universally acceptable and meaningful test method to demonstrate a material's barrier capability under conditions that simulate usual conditions of use. None has been successful. Today, with the trend toward minimally invasive surgery and pressure to reduce costs, perioperative nurses are confronted with selecting a product that is appropriate for the task and degree of exposure anticipated.

Ultraviolet protection factor of fabrics: comparison of laboratory and field-based measurements

BACKGROUND/PURPOSE

Spectrophotometry has become an accepted laboratory-based method for the determination of the ultraviolet protection factor (UPF) of fabrics. However, the validity of the UPF determined in the laboratory has been a controversial issue with regard to its significance in the field. To compare UPF values obtained by spectrophotometry, determination of the minimal erythema dose (MED), and biological dosimetry, we conducted laboratory and field-based measurements on various fabric materials.

METHODS

One cotton, two viscose, and two polyester fabrics were enrolled into the study. Spectrophotometric (SP) testing was performed in accordance with the European standard. In vivo "on skin" (IV) testing on human subjects was performed with and without fabric protection. For determination of MED, a solar-simulator was used. In another part of the study, biological dosimetry (BD) testing was employed for laboratory testing with solar-simulated radiation (laboratory BD testing) as well as field-based measurements with natural sunlight in stationary (stationary BD testing) and "real life" exposure situations (mobile subject BD testing). For field-based measurements one light-weight polyester fabric was selected.

RESULTS

The differences of the mean UPF values obtained by the laboratory-based methods were significant (MANOVA; P = 0.05), except for fabric no. 2 (MANOVA; P = 0.097). In 4 of the 5 fabrics tested, UPF values obtained by IV testing were significantly lower than those obtained by SP testing (t-test; P = 0.05). In 3 fabrics, SP testing revealed significantly higher UPF values in comparison to laboratory BD testing (t-test; P = 0.05). The differences of UPF values obtained by the laboratory and field-based measurements employed for the light-weight polyester fabric were significant (ANOVA; P = 0.05). In comparison to SP testing (UPF 3.8), stationary BD testing resulted in significantly lower (UPF 3.5) and mobile subject BD testing in a significantly higher UPF of 4.4 (t-test; P = 0.05). The UPF obtained by mobile subject BD testing differed significantly from the UPF obtained by stationary BD testing (t-test; P = 0.05).

CONCLUSIONS

Comparison of the presented methods indicates that IV testing generally results in lower UPF values. By contrast BD testing in "real life" exposure situations reveals relatively high UPF values. Although an overestimation of the spectrophotometrically measured UPF has been observed in comparative laboratory testing, UPF values obtained by field-based measurements are in relatively good agreement, or even surpass UPF values obtained by spectrophotometry. It is, therefore, suggested that SP testing provides "safe" UPF values which may be also valid in extreme real exposure situations. Biological UV dosimetry is, however, a promising alternative method for UPF testing: the test is easily performed in realistic exposure situations, the test is relatively inexpensive, and the measurements are valid.

A review of single-use and reusable gowns and drapes in health care

Gowns and drapes are used widely in healthcare facilities. Gowns have been used to minimize the risk of disease acquisition by healthcare providers, to reduce the risk of patient-to-patient transmission, and during invasive procedures to aid in maintaining a sterile field. Drapes have been used during invasive procedures to maintain the sterility of environmental surfaces, equipment, and patients. This article reviews the use of gowns and drapes in healthcare facilities, including the characteristics, costs, benefits, and barrier effectiveness of single-use and reusable products. Currently, gowns protect healthcare personnel performing invasive procedures from contact with bloodborne pathogens. Although gowns have been recommended to prevent patient-to-patient transmission in certain settings (eg, neonatal intensive care unit) and for certain patients (eg, those infected with vancomycin-resistant enterococci), scientific studies have produced mixed results of their efficacy. While appropriate use of drapes during invasive procedures is recommended widely as an aid in minimizing contamination of the operative field, the efficacy of this practice in reducing surgical-site infections has not been assessed by scientific studies. Based on an evaluation of the functional requirements, environmental impact, and economics of gowns and drapes, clear superiority of either reusable or single-use gowns and drapes cannot be demonstrated. The selection of particular gowns and drapes by individual healthcare facilities requires an assessment of the facility's requirements, available products, and costs and should be based on the desired characteristics of an ideal gown or drape as defined in this paper.

An ergonomics investigation into human thermal comfort using an automobile seat heated with encapsulated carbonized fabric (ECF)

This report presents the results of an ergonomics investigation into human thermal comfort using an automobile seat heated with an encapsulated carbonized fabric (ECF). Subjective and objective thermal comfort data were recorded while participants sat for 90 min in a heated and a non-heated automobile seat in an environmental chamber. Eight male participants each completed eight experimental sessions in a balanced order repeated measures experimental design. The conditions in the chamber were representative of a range of cool vehicle thermal environments (5, 10, 15 and 20 degrees C; in the 20 degrees C trial participants sat beside a 5 degrees C 'cold wall'). Participants in the heated seat condition used the heating controller with separate temperature control over the back of the seat (squab) and bottom of the seat (cushion) in an effort to maintain their thermal comfort while wearing the provided clothing, which had an estimated insulation value of 0.9 Clo. The trials showed that participants' overall sensations remained higher than 'slightly cool' in the heated seat at all temperatures. Participants' overall discomfort remained lower (i.e. more comfortable) than 'slightly uncomfortable' at temperatures ranging down to nearly 5 degrees C in the heated seat. Hand and foot comfort, sensation and temperature were similar in both seats. Asymmetric torso and thigh skin temperatures were higher in the heated seat although no significant discomfort was found in the front and back of the torso and thigh in either seat. Participants reported no significant difference in alertness between the control and heated seat.

[Life-cycle assessment of single-use versus reusable surgical drapes (cellulose/polyethylene-mixed cotton system)]

Surgical drapes made of cotton are under increasing competition with various disposable products and reusable draping systems (e.g., made of synthetic fabrics like polyester). When making a choice to use one of these medical devices in practical surgery, major aspects like handling, hygienic safety and costs, but also environmental effects have to be taken into account. In this study a mixed system for patient drapes (reusable cotton drapes combined with a reduced set of impermeable single-use drapes made of cellulose/polyethylene) was compared to a system that is only based on single-use drapes with regard to ecology [life-cycle assessment (LCA)]. The medical literature was reviewed to assess important medical aspects of the use of patient drapes, resulting in the statement that there are no conclusive arguments to support a clear hygienic superiority of one of these alternatives. Based on the conditions assumed and stated, the results of the LCA indicate that the mixed draping system is associated with two times more total energy consumption. In addition, more water is needed and more CO2 emissions are produced. However, draping with the single-use product results in more clinical waste. Regarding water pollution no system proved superior. It is difficult to compare and weigh various environmental aspects like the polluting cultivation of cotton in distant countries (reusable drapes) and the higher figure of transportation necessary to deliver the single-use product within Germany. It is an important disadvantage of the mixed system that it combines the ecological burden of both cotton drapes and the single-use alternative.

Distinguishing between new and slightly worn underwear: a case study

This case study relates to a suspect accused of shop-lifting a pair of underwear briefs from a department store. The report presents a method that was used to distinguish between new and used underwear employing both laser examination for biological staining and microscopical examination for thread wear.

Arrow damage to textiles--analysis of clothing and bedding in two cases of crossbow deaths

Two cases of crossbow deaths involving analysis of damage to clothing and bedding are described. The distinctive characteristics of the damage examined in these cases indicate that there is merit in examining damage to clothing as well as wounds to the body in crossbow injuries. Clothing damage analysis may be especially useful if the body is badly decomposed or never recovered. Furthermore, damage to textiles may reflect a clearer geometry of the weapon than that of the associated wounding.

Clothing as protection from ultraviolet radiation: which fabric is most effective?

BACKGROUND

With increasing levels of solar ultraviolet radiation (UVR) in the earth's near environment and evidence that exposure to UVR contributes to skin cancer, cataracts, and photoaging, protection of the skin is imperative during exposure to the sun. The purpose of this study was to examine the effectiveness of various fabrics in screening UVR and to determine if specific characteristics of fabric are directly related to the amount of protection provided.

METHODS

Transmission of UVR was measured using spectrophotometric techniques. This transmission, as a function of wavelength over the range 250-400 nm, was weighted with solar and biological spectral data to determine a "sun protection factor" (SPF) for each fabric.

RESULTS

The transmission of UVR through fabric depends on the wavelength and varies with factors such as type of fiber, fabric mass, cover, and color.

CONCLUSIONS

Of 28 white fabrics tested, 19 offered less protection than a sunscreen with SPF 15. Polyester fabrics offered increased protection over cotton. The presence of dyes increased protection considerably.

Antimicrobial acetate fibers: a step forward in health care textiles

Health care providers are constantly battling the microorganisms that cause disease and infection. New textile products give professionals another weapon against these microscopic enemies.