Rachel H. McQueen

Odor Intensity in Apparel Fabrics and the Link with Bacterial Populations

Nine apparel fabrics varying in fiber (cotton, wool, polyester) and knit structure (1 × 1 rib, interlock, single jersey) were investigated for their retention of axillary odor following wear. As axillary odor results from bacterial metabolism of apocrine and sebaceous secretions, counts of total aerobic bacteria and corynebacteria on the fabrics were carried out. Odor intensity was strongly associated with the fiber type, with polyester fabrics rating high in odor intensity and cotton and wool mid-low odor intensity. A structure effect was apparent for polyester fabrics, with the lightweight single jersey fabric rated less odorous than the heavier-weight interlock and 1 × 1 rib structures. The relationship between fiber type and odor was not influenced by bacterial numbers present, with counts after one day similar for all fabrics. However, the number of bacteria declined more rapidly on polyester fabrics than on either the cotton or wool fabrics. Counts of odor-associated corynebacteria subgroup (A) remained largely unchanged on wool fabrics for 28 days.

Retention of axillary odour on apparel fabrics

Abstract Clothing worn in close proximity to the human axilla can retain and emanate human body odour even remaining odorous long after removal from the body. Intensity of odour is affected by the fibre type from which the garment is made. Headspace analysis of axillary volatile compounds released from three interlock fabrics (cotton, wool, polyester) following wear were measured using an online monitoring instrument, proton transfer reaction-mass spectrometry (PTR-MS). Compounds likely to be short-chain carboxylic acids increased in the headspace above the polyester fabrics after 7 days. This increase was not evident above either the wool or cotton fabrics. The intensity of axillary odour emanating from these fabrics was inversely related to fibre hygroscopicity. The relationship between a textile fibre/fabrics ability to retain and emanate odour is likely to be related to the metabolic versatility of resident microbial strains and/or the chemical and physical morphology of the fibre and its ability to absorb volatile compounds and precursors to odour.

From Clothing to Laundry Water: Investigating the Fate of Phthalates, Brominated Flame Retardants, and Organophosphate Esters

The accumulation of phthalate esters, brominated flame retardants (BFRs) and organophosphate esters (OPEs) by clothing from indoor air and transfer via laundering to outdoors were investigated. Over 30 days cotton and polyester fabrics accumulated 3475 and 1950 ng/dm(2) ∑5phthalates, 65 and 78 ng/dm(2) ∑10BFRs, and 1200 and 310 ng/dm(2) ∑8OPEs, respectively. Planar surface area concentrations of OPEs and low molecular weight phthalates were significantly greater in cotton than polyester and similar for BFRs and high molecular weight phthalates. This difference was significantly and inversely correlated with KOW, suggesting greater sorption of polar compounds to polar cotton. Chemical release from cotton and polyester to laundry water was >80% of aliphatic OPEs (log KOW < 4), < 50% of OPEs with an aromatic structure, 50-100% of low molecular weight phthalates (log KOW 4-6), and < detection-35% of higher molecular weight phthalates (log KOW > 8) and BFRs (log KOW > 6). These results support the hypothesis that clothing acts an efficient conveyer of soluble semivolatile organic compounds (SVOCs) from indoors to outdoors through accumulation from air and then release during laundering. Clothes drying could as well contribute to the release of chemicals emitted by electric dryers. The results also have implications for dermal exposure.

In vivo assessment of odour retention in an antimicrobial silver chloride-treated polyester textile

The purpose of this study was to determine whether polyester textiles treated with bioactive concentrations of an antimicrobial silver chloride (SC) compound were effective in reducing axillary odour and axillary bacterial populations before and after multiple washes. A polyester knit fabric was treated with two concentrations of a SC formulation (resulting in 30 and 60 ppm of silver) and evaluated at two levels of wash treatments (unwashed and washed 30 times). Treated fabrics were matched with an untreated control fabric and worn against the axillae of male participants (n = 8). A sensory panel evaluated odour intensity using two different methods (paired comparison and line scale method). Overall, results showed that the treated fabrics did not lower odour intensity compared with the untreated fabrics. Bacterial populations extracted from the treated fabrics were also not significantly lower, despite there being evidence of antimicrobial activity in in vitro testing. The paired comparison method was found to be more sensitive in detecting small differences between treated and untreated fabrics. However, the line scale method was deemed to be a more appropriate method for evaluating odour intensity on fabrics because the magnitude of the difference could be assessed. It is recommended that as in vitro efficacy does not necessarily predict in vivo efficacy of an antimicrobial treatment that sensory evaluation and in vivo testing should be conducted when examining the odour reducing properties of an antimicrobial.

Odor Retention on Apparel Fabrics: Development of Test Methods for Sensory Detection

A method for collecting axillary odor on nine knit fabrics was developed and odor intensity determined using a panel of assessors. Two methods, one involving paired-comparisons in the quad analysis method and the other a line scale, were investigated to determine if differences in intensity of odor retained on the fabrics varying by fiber and fabric structure could be detected. Both methods allowed detection of differences. However, the line scale method was more time-efficient and enabled a greater number of assessors on the panel, an advantage for reducing the effect of individual differences in sensitivity to axillary odorants. Recommendations for a collection method, handling and assessment method are raised.

Axillary odour build-up in knit fabrics following multiple use cycles

Purpose – Fibre content can influence the intensity of odour that develops within clothing fabrics. However, little is known about how effective laundering is at removing malodours in clothing which differ by fibre type. The purpose of this paper is to investigate whether a selected cotton fabric differed in odour intensity following multiple wear and wash cycles compared to a polyester fabric. Design/methodology/approach – Eight (male and female) participants wore bisymmetrical cotton/polyester t-shirts during 20 exercise sessions over a ten-week trial period. Odour was evaluated via a sensory panel, bacterial populations were counted and selected odorous volatile organic compounds were measured with comprehensive two-dimensional gas chromatography and time-of-flight mass spectrometry detection. Analysis occurred both before and after the final (20th) wash cycle. Findings – Findings showed that laundering was effective in reducing overall odour intensity (p0.001) and bacterial populations (p0.001) in b...

In vivo assessment of antimicrobial-treated textiles on skin microflora

Purpose – Antimicrobials may be incorporated into garments to protect the textiles, control malodour or to potentially reduce the spread of infection. Yet still not well understood is how antimicrobial-treated textiles may influence a persons resident microflora during wear, as limited in vivo testing has previously been carried out. The purpose of this paper is to assess whether normal skin microflora was altered as a result of contact with selected antimicrobial-treated fabrics. Design/methodology/approach – Three selected antimicrobial-treated fabrics (i.e. Fabric 1: triclosan; Fabric 2: zinc pyrithione derivative; and Fabric 3: silver chloride and titanium dioxide) were placed on the forearm of participants (n=19). Bacterial counts obtained under treated and untreated fabrics following 24 hours of occlusion were compared. The antimicrobial efficacy of fabrics displayed in vitro was also compared with the activity displayed in vivo. Findings – Two of the three fabrics (Fabrics 1 and 2) reduced bacteri...

Comprehensive two-dimensional gas chromatographic profiling and chemometric interpretation of the volatile profiles of sweat in knit fabrics

AbstractHuman axillary sweat is a poorly explored biofluid within the context of metabolomics when compared to other fluids such as blood and urine. In this paper, we explore the volatile organic compounds emitted from two different types of fabric samples (cotton and polyester) which had been worn repeatedly during exercise by participants. Headspace solid-phase microextraction (SPME) and comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry (GC×GC-TOFMS) were employed to profile the (semi)volatile compounds on the fabric. Principal component analysis models were applied to the data to aid in visualizing differences between types of fabrics, wash treatment, and the gender of the subject who had worn the fabric. Statistical tools included with commercial chromatography software (ChromaTOF) and a simple Fisher ratio threshold-based feature selection for model optimization are compared with a custom-written algorithm that uses cluster resolution as an objective function to maximize in a hybrid backward-elimination forward-selection approach for optimizing the chemometric models in an effort to identify some compounds that correlate to differences between fabric types. The custom algorithm is shown to generate better models than the simple Fisher ratio approach. Graphical AbstractA route from samples and questions to data and then answers

Modelling the physiological strain and physical burden of chemical protective coveralls

This study determined the impact of selected chemical protective coveralls (CPC) on physiological responses and comfort sensations. Fifteen males exercised at approximately 6 METS in three CPC (Tyvek®, Gulf and Tychem®) and a control garment. Physiological strain was characterised by core and skin temperatures, heart rate, , perceived exertion, hotness and wetness. Physical burden was characterised by restriction to movement, and RPE. The highest levels of physiological strain and physical burden were found in Tychem®, and the lowest in control. Seven statistical regression models were developed through correlation and multiple regression analyses between the human responses and the results from previously conducted fabric and garment property testing. These models showed that physical burden was increased by adding weight and/or restricting movement. Oxygen consumption was best predicted by clothing weight and fabric bending hysteresis. Fabric evaporative resistance and thickness were the two best predictors of physiological and perceptual responses. Practitioner Summary: Traditional evaluation of chemical protective coveralls (CPC) involves testing at the fabric and garment levels and rarely is based on human trials. This study integrates information from fabric, garment and human trials to better understand physiological strain and physical comfort during prolonged exercise in CPC.

Antimicrobial Textiles and Infection Prevention: Clothing and the Inanimate Environment

Textiles are ubiquitous and an essential part of human society. Within the hospital environment, textiles have many functions, such as the clothing worn by patients and healthcare workers, the towels and cloths used to contain and mop up fluids, drapes used to isolate and maintain sterility during surgery, furnishings such as upholstered chairs as well as curtains, carpets and also bedding. As part of the inanimate environment, textiles could act as a potential source of infection (Borkow G, Gabbay J. Med Hypotheses 70(5):990–994, 2008; Wiener-Well Y et al Am J Infect Control 39(7):555–559, 2011). This is because microorganisms can be transferred from an infected patient, a healthcare worker or some environmental source and persist within the textile then to be transferred to a susceptible individual. Frequent and effective laundering is the most common and most effective strategy for reducing microbial burden on textiles (Fijan S, Turk SS. Int J Environ Res Public Health 9(9):3330–3343, 2012). However, not all textiles in the hospital setting are frequently laundered (e.g. privacy curtains) or easily laundered (e.g. upholstery on chairs). As well, within a typical work shift (8–12 h) the microbial load on a healthcare workers’ clothing could become significant (Burden M et al J Hosp Med 6(4):177–182, 2011), and thus the transmission of pathogenic microorganisms may be possible. A possible solution to the problem of relying solely on cleaning involves integrating biocidal textiles into the hospital environment in order to reduce the microbial burden to levels low enough to reduce the rate of hospital-acquired infections (HAIs) (Borkow G, Gabbay J. Med Hypotheses 70(5):990–994, 2008). The purpose of this chapter is to review the literature pertaining to contamination of hospital textiles by potentially pathogenic microorganisms and the related transmission of HAIs, describe the antimicrobials agents incorporated in textiles, describe the in vitro standard test methods used to assess antimicrobial efficacy and evaluate the effectiveness of antimicrobial-treated textiles in the hospital environment.