Protective Clothing Ensembles Research Articles

Anthropometric Fit Test Methods: Three Case Studies

There is not a universally accepted fit test procedure because test protocols need to be customized for specific products or research questions. A fit test protocol can vary significantly based on the product tested, but often includes these steps: define fit criteria, select anthropometric dimensions of interest, perform testing, collect quantitative and qualitative feedback, identify design recommendations, and develop or refine a sizing chart. To illustrate general approaches to human fit testing, case studies of fit tests are described for three different product types: a multi-layered protective clothing ensemble, a therapeutic airway clearance vest, and a patient transfer sling.

A Database of Static Thermal Insulation and Evaporative Resistance Values of Dutch Firefighter Clothing Items and Ensembles.

The rescue operations' environment can impair firefighters' performance and increase the risk of injuries, e.g., burns and hyperthermia. The bulk and carried weight of heavy protection contributes to lower physical performance, higher metabolic load and internal body heat production. For recommending optimal protection for the tasks and incident scenarios, knowledge of clothing thermal properties is needed. However, detailed data on firefighter protective clothing systems are not available. The aim of the study was to provide scientific background and a dataset that would allow for validation of thermo-physiological models for task-specific conditions of rescue work. Thermal insulation of 37 single items and their variations and 25 realistic protective clothing ensembles were measured on a thermal manikin. Twelve (12) ensembles that evenly covered the whole insulation range were selected for evaporative resistance testing. The equations for summing up individual item's insulation to ensemble insulation and calculating clothing area factor were derived from the dataset. The database of a firefighter clothing system was created. In addition, the local and regional thermal properties of the clothing ensembles were provided for use in future validation of advanced thermo-physiological models for rescue worker exposure predictions and for designing decision aid tools.

Modified Stroop task performance when wearing protective clothing in the heat: An evaluation of the maximum adaptability model

IntroductionThis exploratory study investigated whether performance in a behavioural inhibition task followed the shape proposed by the Maximum Adaptability Model during progressive exertional heat stress—that is, an initial improvement in cognitive performance is followed by a plateau, and subsequent decline once body temperature continues to rise unabated. MethodsSeventeen adult males walked on a treadmill at 4 km h−1 (1% grade) for up to 120 min, in three protective clothing ensembles, across three simulated environments. The simulated environments were equivalent to wet bulb globe temperatures 21, 30 and 37 °C. Cognitive function was assessed using a modified colour-word Stroop Task, with performance expressed as inverse efficiency scores in the simple (congruent) and more complex (incongruent) task conditions. The Stroop Task was completed before a trial, at termination, and every 30 min during walking, and core body temperature was continuously measured. Data were modelled using Bayesian penalised regression, with core body temperature included as a non-linear term (i.e., second degree polynomial). ResultsWe did not find any evidence that core body temperature had an effect on congruent or incongruent inverse efficiency scores, and no evidence that the relationship between these variables followed the shaped described by the Maximum Adaptability Model. There was, however, evidence that higher pre-exercise serum osmolality values were associated with slower congruent (β = 9.19) and incongruent (β = 8.67) inverse efficiency scores. The posterior probability that these effects were greater than zero was 0.971 and 0.952, respectively. ConclusionsIn young, fit men, performance in the behavioural inhibition task was unaffected by increases in body temperature up to 39 °C and did not follow the shape proposed by the Maximum Adaptability Model. A secondary finding of the study was that pre-exercise hydration status affected performance in the inhibition task. Future studies are needed to confirm this result.

Heat-related knowledge, perceptions, and needs among oil spill cleanup responders

BACKGROUND: Occupational exposure to heat and hot environments can result in heat-related illness (HRI), injury, and death among workers, particularly those in outdoor environments such as oil spill cleanup responders. Education and training can help prevent these detrimental heat-related health outcomes. PURPOSE: This study assessed: heat-related knowledge, perceptions, and barriers among oil spill cleanup responders, and heat-related training and educational materials currently used and desired. METHODS: A needs assessment was completed by 65 oil spill cleanup responders regarding their occupational heat-related experiences during oil spill cleanup activities and training needs. RESULTS: Most respondents had 25 or more years' experience (52.4%), worked for companies with 19 or fewer employees (53.5%), and were not classified as safety and health professionals (67.7%). Responders reported experiencing HRI risk factors, such as, high temperatures (71.9%) and humidity (85.9%), and wearing personal protective equipment (PPE) and clothing ensembles (96.9%), respirators (71.9%), and personal flotation devices (78.1%). Many reported experiencing symptoms of HRI (41.5%), and 11% reported experiencing heat exhaustion. While most respondents were knowledgeable of heat stress, they were least knowledgeable about: differentiating between heat exhaustion and heat stroke (12.5% responded correctly), salt tablet usage (62.5% responded correctly), effects of air conditioning on acclimatization (70.3% responded correctly), and previous HRI as a risk factor (73.4% responded correctly). Respondents reported they perceived heat stress to be severe and that HRIs affect workers; and most reported feeling confident in recognizing signs and symptoms of HRI, and knowing what to do if a coworker became ill. While multiple prevention controls were reported, only one in four reported using an acclimatization plan. The most common training and education received included just-in-time training (68.9%) and printed materials (50.8%). The most desirable future training and education products were smartphone or tablet applications (61.0%), printed materials (51.2%), and online training (46.3%). DISCUSSION: Oil spill cleanup responders are at high risk for HRI, injury, and death; and those responsible for their training need to be knowledgeable about all the aspects of occupational heat stress. Findings from this study may be beneficial to safety and health professionals and health educators, particularly those interested in developing heat stress training and educational materials for oil spill cleanup responders.

The effect of the type of protective suit on the thermophysiological comfort of surgeons in an operating room

Surgical gowns and medical clothing have to protect the surgeons from the patient and vice versa. However, all players in the operating room (OR) have to be in a state of thermophysiological comfort. The comfort of the surgeons is of special importance, as they are exposed to stressful situations, which could influence their performance negatively. The study presents an analysis of the thermophysiological comfort of the surgeons in an OR, using protective clothing ensembles with different clothing insulation and protection: a surgical scrub suit (SSS) and a clean air suite (CAS). The analysis is based on the calculation of PMV-PPD indexes, following Fanger’s model. Different combinations of thermal environment parameters and clothing insulation are tested and analysed.

Assessment of effectivness of protective clothing while spraying pesticides

Farming without spraying pesticides is unheard of, unless it is organic farming. Pesticide residues are reported to cause health hazards to many farmers globally. Hence the present study aims at studying the effectiveness of protective clothes while spraying pesticides. The protective clothing ensemble includes scarf/cap (head cover), glasses (eye cover), mask (mouth cover), gloves (hands cover), shirt (body cover), pant (legs cover) and boots (feet cover). The results of three year data shows that 80% of the people have encountered health problems caused due to spraying when protective aids but the same was reduced after usage of protective clothing. All the subjects were of the opinion that the protective clothing was comfortable to use, suitable to the farming operations and was durable as well.

Heat Strain Decision Aid (HSDA) accurately predicts individual-based core body temperature rise while wearing chemical protective clothing

PurposeWe examined the accuracy of the Heat Strain Decision Aid (HSDA) as a predictor of core body temperature in healthy individuals wearing chemical protective clothing during laboratory and field exercises in hot and humid conditions. MethodsThe laboratory experiment examined three chemical protective clothing ensembles in eight male volunteers (age 24 ± 6 years; height 178 ± 5 cm; body mass 76.6 ± 8.4 kg) during intermittent treadmill marching in an environmental chamber (air temperature 29.3 ± 0.1 °C; relative humidity 56 ± 1%; wind speed 0.4 ± 0.1 m s−1). The field experiment examined four different chemical protective clothing ensembles in twenty activity military volunteers (26 ± 5 years; 175 ± 8 cm; 80.2 ± 12.1 kg) during a prolonged road march (26.0 ± 0.5 °C; 55 ± 3%; 4.3 ± 0.7 m s−1). Predictive accuracy and precision were evaluated by the bias, mean absolute error (MAE), and root mean square error (RMSE). Additionally, accuracy was evaluated using a prediction bias of ±0.27 °C as an acceptable limit and by comparing predictions to observations within the standard deviation (SD) of the observed data. ResultsCore body temperature predictions were accurate for each chemical protective clothing ensemble in laboratory (Bias −0.10 ± 0.36 °C; MAE 0.28 ± 0.24 °C; RMSE 0.37 ± 0.24 °C) and field experiments (Bias 0.23 ± 0.32 °C; MAE 0.30 ± 0.25 °C; RMSE 0.40 ± 0.25 °C). From all modeled data, 72% of all predictions were within one standard deviation of the observed data including 92% of predictions for the laboratory experiment (SD ± 0.64 °C) and 67% for the field experiment (SD ± 0.38 °C). Individual-based predictions showed modest errors outside the SD range with 98% of predictions falling <1 °C; while, 81% of all errors were within 0.5 °C of observed data. ConclusionThe HSDA acceptably predicts core body temperature when wearing chemical protective clothing during laboratory and field exercises in hot and humid conditions.

Guidelines for the specification of a PCM layer in firefighting protective clothing ensembles

Phase change materials are increasingly seen not only as a solution to reduce the mismatch between demand and supply of energy, but also as an adequate tool for heat management. Firefighters usually encounter high heat flux exposures, which can cause severe burns. The addition of a PCM layer into a typical firefighting garment ensemble can be used to mitigate this effect, increasing the time to second-degree burns. A numerical approach was used to investigate the effect of PCM latent heat, mass, melting temperature, and position within the garment ensemble, to assess the implications in terms of thermal performance and time to second-degree burns, under high-, medium- and low-intensity heat exposures. Guidelines for the specification of PCM characteristics are provided with respect to the heat exposure scenario considered, to enable informed decisions regarding the choice and features of the PCM, in function of the intended application and required time-windows without burns. The data discussed in this work provide insight on how a PCM layer influences the thermal burden on a firefighter, which enables the estimation of optimal PCM masses, and thus the minimization of the load to be carried by the firefighter, and the costs associated with the integration of high loads of PCM in a garment.

Heat-Related Training and Educational Material Needs among Oil Spill Cleanup Responders.

Heat-related illness (HRI), injury, and death among oil spill cleanup responders can be prevented through training and educational materials. This study assessed heat-related training and educational materials currently used and desired by oil spill cleanup responders. A needs assessment was completed by 65 oil spill cleanup responders regarding their occupational heat-related experiences and training needs. Oil spill cleanup responders reported participating on average in 37 oil spill cleanup activities per year. Most reported experiencing additional HRI risk factors, such as high temperatures and humidity and wearing personal protective equipment and clothing ensembles, respirators, and personal flotation devices. Many reported experiencing symptoms of HRI (profuse sweating, headache, weakness, decreased urine output, high body temperatures) and experiencing heat exhaustion. Although multiple prevention controls were reported, only 1 in 4 reported using an acclimatization plan. The most common training delivery method and education received included just-in-time training and printed materials. The most desirable future training delivery methods and education products were smartphone or tablet applications, printed materials, and online training. Findings from this study may be beneficial to safety and health professionals and health educators, particularly those interested in developing heat stress training and educational materials for oil spill cleanup responders.

The usage of phase change materials in fire fighter protective clothing: its effect on thermal protection

The thermal protective performance of the fire fighter protective clothing is of vital importance for fire fighters. In the study fabrics treated by phase change materials (PCMs) were applied in the multi-layered fabrics of the fire fighter protective clothing ensemble. The PCM fabrics were placed at the different layers of the clothing and their thermal protective performance were measured by a TPP tester. Results show that with the application of the PCM fabrics the thermal protection of the multi-layered fabrics was greatly increased. The time to reach a second degree burn was largely reduced. The location of the PCM fabrics at the different layers did not affect much on the thermal protective performance. The higher amount of the PCM adds on, the higher thermal protection was brought. The fabrics with PCMs of a higher melting temperature could contribute to higher thermal protection.

Evaluation of a passive method for determining particle penetration through protective clothing materials

ABSTRACTThe risk of workers' exposure to aerosolized particles has increased with the upsurge in the production of engineered nanomaterials. Currently, a whole-body standard test method for measuring particle penetration through protective clothing ensembles is not available. Those available for respirators neglect the most common challenges to ensembles, because they use active vacuum-based filtration, designed to simulate breathing, rather than the positive forces of wind experienced by workers. Thus, a passive method that measures wind-driven particle penetration through ensemble fabric has been developed and evaluated. The apparatus includes a multidomain magnetic passive aerosol sampler housed in a shrouded penetration cell. Performance evaluation was conducted in a recirculation aerosol wind tunnel using paramagnetic Fe3O4 (i.e., iron (II, III) oxide) particles for the challenge aerosol. The particles were collected on a PVC substrate and quantified using a computer-controlled scanning electron microscope. Particle penetration levels were determined by taking the ratio of the particle number collected on the substrate with a fabric (sample) to that without a fabric (control). Results for each fabric obtained by this passive method were compared to previous results from an automated vacuum-based active fractional efficiency tester (TSI 3160), which used sodium chloride particles as the challenge aerosol. Four nonwoven fabrics with a range of thicknesses, porosities, and air permeabilities were evaluated. Smoke tests and flow modeling showed the passive sampler shroud provided smooth (non-turbulent) air flow along the exterior of the sampler, such that disturbance of flow stream lines and distortion of the particle size distribution were reduced. Differences between the active and passive approaches were as high as 5.5-fold for the fabric with the lowest air permeability (0.00067 m/sec-Pa), suggesting the active method overestimated penetration in dense fabrics because the active method draws air at a constant flow rate regardless of the resistance of the test fabric. The passive method indicated greater sensitivity since penetration decreased in response to the increase in permeability.

Thermo-physiological impact of different firefighting protective clothing ensembles in a hot environment

It is currently unclear how the assembly of different fabric layers of personal protective clothing (PPC) contributes to differences in thermal comfort among garments. Therefore, we used two different approaches to investigate the effect of PPC on body heat dissipation: a technical characterization of textiles (using sweating Torso methodology) and thermo-physiological wearing trials. We hypothesized that the technical characterization provides a similar outcome compared to the wearing trials and, thus, proves to have high thermo-physiological relevance. Thirteen different PPC were investigated using the sweating Torso methodology. Three out of these thirteen were then selected for inclusion in a series of human subject trials in a hot environment. Results from human trials and Torso testing were related to each other. The thermal and evaporative properties of the selected PPC typically differed and effects were observed for the thermo-physiological responses of human study participants. Differences in Torso surface temperature of up to 9℃ and moisture accumulation in the protective clothing systems of up to 184 g·m–2 were detected using the sweating Torso methodology. Moderate intensity exercise with the human study participants induced textile-dependent differences of up to 0.9 ± 0.2℃ ( P &lt; 0.001) and 1.2 ± 0.2℃ ( P = 0.008) for excessive core body and excessive skin temperature, respectively. Using the sweating Torso methodology, physiologically relevant differences in textile performance could be detected among different PPC. Consequently, sweating Torso is a relevant tool to gain insight into human thermo-physiological responses to different PPC with similar end-use based on their dry and wet heat transfer characteristics.

Protective clothing ensembles and physical employment standards.

Physical employment standards (PESs) exist for certain occupational groups that also require the use of protective clothing ensembles (PCEs) during their normal work. This review addresses whether these current PESs appropriately incorporate the physiological burden associated with wearing PCEs during respective tasks. Metabolic heat production increases because of wearing PCE; this increase is greater than that because of simply the weight of the clothing and can vary 2-fold among individuals. This variation negates a simple adjustment to the PES for the effect of the clothing on metabolic rate. As a result, PES testing that only simulates the weight of the clothing and protective equipment does not adequately accommodate this effect. The physiological heat strain associated with the use of PCEs is also not addressed with current PESs. Typically the selection tests of a PES lasts less than 20 min, whereas the requirement for use of PCE in the workplace may approach 1 h before cooling strategies can be employed. One option that might be considered is to construct a heat stress test that requires new recruits and incumbents to work for a predetermined duration while exposed to a warm environmental temperature while wearing the PCE.

Critical WBGT for 4 protective clothing made of fabrics with different Total Heat Loss values

Managing heat stress in the workplace while wearing protective clothing (PC) is critical for worker safety and health. There is a variety of PC, such as fire-fighting ensembles, emergency medical clothing, CBRN suits, etc., designed to protect the wearer's body from specific hazards, which have different levels of protection and thus different clothing thermal characteristics (thermal and vapour resistances). This study evaluated the critical wet bulb globe temperature (WBGTcrit) of PC ensembles with four different total heat loss values determined by a sweating hotplate (SHP) test.

Heat stress evaluation of two-layer chemical demilitarization ensembles with a full face negative pressure respirator.

The purpose of this study was to examine the heat stress effects of three protective clothing ensembles: (1) protective apron over cloth coveralls including full face negative pressure respirator (APRON); (2) the apron over cloth coveralls with respirator plus protective pants (APRON+PANTS); and (3) protective coveralls over cloth coveralls with respirator (PROTECTIVE COVERALLS). In addition, there was a no-respirator ensemble (PROTECTIVE COVERALLS-noR), and WORK CLOTHES as a reference ensemble. Four acclimatized male participants completed a full set of five trials, and two of the participants repeated the full set. The progressive heat stress protocol was used to find the critical WBGT (WBGTcrit) and apparent total evaporative resistance (Re,T,a) at the upper limit of thermal equilibrium. The results (WBGTcrit [°C-WBGT] and Re,T,a [kPa m2 W−1]) were WORK CLOTHES (35.5, 0.0115), APRON (31.6, 0.0179), APRON+PANTS (27.7, 0.0244), PROTECTIVE COVERALLS (25.9, 0.0290), and PROTECTIVE COVERALLS-noR (26.2, 0.0296). There were significant differences among the ensembles. Supporting previous studies, there was little evidence to suggest that the respirator contributed to heat stress.

The influence of fabric air permeability on the efficacy of ventilation features

Purpose – The purpose of this investigation was to measure the changes in effective thermal insulation caused by three different types of outer garment ventilation features (chest zips, back zips and pit zips) when combined with either a high or low air permeability insulating layer. Design/methodology/approach – The measurements in this investigation were made with a thermal manikin and with a 26 zone thermal torso. Measurements were made at two air flow speeds with each manikin; the different air flow characteristics for each manikin allowed investigation of how ventilation features interact with different air flow distributions. Findings – It was established in this study that high permeability insulation increases the efficacy of ventilation features by an average of 7 per cent at the low wind speed and 10 per cent at the high wind speed. No particular ventilation feature was found to be consistently the most effective; the data suggest that garment openings should simply be located in well-ventilated areas. Originality/value – This investigation analysed the ventilation characteristics of protective clothing ensembles with different ventilation features, allowing designers to create more comfortable clothing for work and leisure activities.

Can the PHS model (ISO7933) predict reasonable thermophysiological responses while wearing protective clothing in hot environments?

In this paper, the prediction accuracy of the PHS (predicted heat strain) model on human physiological responses while wearing protective clothing ensembles was examined. Six human subjects (aged 29 ± 3 years) underwent three experimental trials in three different protective garments (clothing thermal insulation Icl ranges from 0.63 to 2.01 clo) in two hot environments (40 °C, relative humidities: 30% and 45%). The observed and predicted mean skin temperature, core body temperature and sweat rate were presented and statistically compared. A significant difference was found in the metabolic rate between FIRE (firefighting clothing) and HV (high visibility clothing) or MIL (military clothing) (p < 0.001). Also, the development of heart rate demonstrated the significant effects of the exposure time and clothing ensembles. In addition, the predicted evaporation rate during HV, MIL and FIRE was much lower than the experimental values. Hence, the current PHS model is not applicable for protective clothing with intrinsic thermal insulations above 1.0 clo. The results showed that the PHS model generated unreliable predictions on body core temperature when human subjects wore thick protective clothing such as firefighting clothing (Icl > 1.0 clo). The predicted mean skin temperatures in three clothing ensembles HV, MIL and FIRE were also outside the expected limits. Thus, there is a need for further extension for the clothing insulation validation range of the PHS model. It is recommended that the PHS model should be amended and validated by individual algorithms, physical or physiological parameters, and further subject studies.

A CB Protective Firefighter Turnout Suit

This paper describes research that developed a prototype chemical and biological (CB) protective firefighter suit. It is presented as a case study demonstrating an integrated systems approach to designing, developing and evaluating a protective clothing ensemble based on end user requirements. It includes a discussion of the process that was used to gain an understanding of firefighter performance needs for a structural turnout suit that also incorporated chemical protection. It describes the design features of the turnout suit that were developed to meet these expectations as well as the program of testing and evaluation used to characterize garment performance. It discusses ensemble level performance evaluations in instrumented fire manikin tests and man-in-stimulant test procedures. It describes studies conducted to determine the impact of prototype garment design features on heat stress, wear comfort and ergonomic function in structural firefighting applications.

Thermal Resistance Properties of Paratrooper Clothing

Combat free fall paratroopers’ (CFF) protective clothing, comprising of non-woven insulating material, inherently flame retardant Nomex fabric and cotton fabric combinations are studied under simulated conditions of conduction and sweat using Thermolobo-II technique. The results show that Non—woven insulating materials exhibit high thermal resistance in dry contact method under moderate wind velocity, whereas the thermal resistance values measured under wet conditions is significantly lower. The effect of air layer thickness, permeability and other important parameters, such as porosity, surface area have also been considered and correlated to assess the overall performance of protective clothing ensemble.

Review of Chamber Design Requirements for Testing of Personal Protective Clothing Ensembles

This review focuses on the physical requirements for conducting ensemble testing and describes the salient issues that organizations involved in the design, test, or certification of personal protective equipment (PPE) and protective clothing ensembles need to consider for strategic planning. Several current and proposed PPE ensemble test practices and standards were identified. The man-in-simulant test (MIST) is the primary procedure used by the military to evaluate clothing ensembles for protection against chemical and biological warfare agents. MIST has been incorporated into the current editions of protective clothing and equipment standards promulgated by the National Fire Protection Association (NFPA). ASTM has recently developed a new test method (ASTM F 2588-06) for MIST evaluation of protective ensembles. Other relevant test methods include those described in International Organization for Standardization (ISO) standards. The primary differences among the test methods were the choice of test challenge material (e.g., sulfur hexafluoride, methyl salicylate, sodium chloride particles, corn oil, fluorophore-impregnated silica) and the exercise protocol for the subject(s). Although ensemble test methods and standards provide detailed descriptions of the test procedures, none give specific requirements for chamber design. A literature survey identified 28 whole-body exposure chambers that have been or could potentially be used for testing protective clothing ensembles using human test subjects. Median chamber size, median floor space, and median volume per subject were calculated from 15 chambers (involving human test subjects), where size information is available. Based on the literature survey of existing chambers and the review of the current and proposed standards and test methods, chamber design requirements will be dictated by the test methods selected. Due to widely different test conditions for aerosol/particulate and vapor ensemble testing, it is unlikely that a single chamber could accommodate all types of ensemble testing. With increasing use of the MIST protocol by NFPA for CBRN certification of structural firefighting gear and protective ensembles for first responders, the need for MIST laboratory capability is clear. However, existing chambers can likely be adapted to accommodate MIST with some modifications.