Calculation of Clothing Insulation by Serial and Parallel Methods: Effects on Clothing Choice by IREQ and Thermal Responses in the Cold

Cold protective clothing was studied in 2 European Union projects. The objectives were (a) to examine different insulation calculation methods as measured on a manikin (serial or parallel), for the prediction of cold stress (IREQ); (b) to consider the effects of cold protective clothing on metabolic rate; (c) to evaluate the movement and wind correction of clothing insulation values.

Tests were carried out on 8 subjects. The results showed the possibility of incorporating the effect of increases in metabolic rate values due to thick cold protective clothing into the IREQ model. Using the higher thermal insulation value from the serial method in the IREQ prediction, would lead to unacceptable cooling of the users. Thus, only the parallel insulation calculation method in EN 342:2004 should be used. The wind and motion correction equation (No. 2) gave realistic values for total resultant insulation; dynamic testing according to EN 342:2004 may be omitted.     

Calculation of clothing insulation by serial and parallel methods: effects on clothing choice by IREQ and thermal responses in the cold.

Cold protective clothing was studied in 2 European Union projects. The objectives were (a) to examine different insulation calculation methods as measured on a manikin (serial or parallel), for the prediction of cold stress (IREQ); (b) to consider the effects of cold protective clothing on metabolic rate; (c) to evaluate the movement and wind correction of clothing insulation values. Tests were carried out on 8 subjects. The results showed the possibility of incorporating the effect of increases in metabolic rate values due to thick cold protective clothing into the IREQ model. Using the higher thermal insulation value from the serial method in the IREQ prediction, would lead to unacceptable cooling of the users. Thus, only the parallel insulation calculation method in EN 342:2004 should be used. The wind and motion correction equation (No. 2) gave realistic values for total resultant insulation; dynamic testing according to EN 342:2004 may be omitted.     

Physiological evaluation of chemical protective suit systems (CPSS) in hot conditions.

This job-related experiment investigated physiological strain in subjects wearing impermeable chemical protective suit systems (CPSSs) weighing about 28 kg. Two types of CPSSs were studied: the self-contained breathing apparatus was carried either inside or outside the suit. Eight healthy and physically fit male firefighter instructors aged 32 to 45 years volunteered for the study. The test drill, performed at a dry, windless ta of 40 degrees C, was divided into 2 consecutive work sessions of 14.5 min (a 20-min rest between) including typical operational work tasks. Considerable thermal and maximal cardiovascular strain and intense subjective discomfort measured in the firefighters emphasize the need to limit working time in hot conditions to only 10-12 min while wearing CPSSs. The present results indicate that the exceptionally heavy physical load and psychological stress during operations in chemical emergencies must be considered in the assessment of the cardiovascular capacity of ageing firefighters using CPSSs.     

基于IREQ模型的低温环境应急救援人员冷应激分析

为更准确地评估低温环境下应急救援人员冷应激情况,避免低温伤害。基于国家推荐性标准GB/T 24254—2009确定我国低温冰冻灾害应急救援作业工作服装热阻（IREQ）,并引入适合描述我国低温冰冻灾害高强度应急救援作业的人体储热率参数,对所需IREQ模型进行改进。计算分析低温冰冻灾害环境下应急救援人员的修正服装热阻、有限持续暴露时间、体温恢复时间。研究结果表明:改进的 IREQ模型计算所得的基本需求热阻更高,有限持续暴露时间更低,对提高低温环境下的应急救援作业安全性具有一定的科学意义。     

Age-related thermal strain in men while wearing radiation protective clothing during short-term exercise in the heat.

The aim of the study was to compare heat strain among different age groups of men in protective clothing during short-term physical work. Eight young (20-29 years), 6 middle-aged (41-55 years), and 6 older (58-65 years) men exercised for 30 min on a cycle ergometer (40% V(O2 max)) in 2 hot environments with a similar WBGT (ca. 26 degrees C): once with minimal clothing without infrared radiation (E1), and once with aluminized protective clothing under infrared radiation (E2). All subjects had sedentary jobs, but only the older subjects were physically active in their leisure-time. Body temperatures, heart rate, sweat rate, and subjective feelings were determined during the tests. Higher thermal strain was observed in E2 than in E1. No age-related differences in thermal strain were observed in either experiment indicating that active older men can tolerate short work periods with protective clothing in the heat as well as younger sedentary men.     

常用高、低温防护服着装舒适性研究

防护服装的全面评价通常涉及安全性、工效学特性等多个方面。在常用高、低温防护服隔热性能研究基础上,对服装的舒适性进行了初步研究,以期为高低温防护服的选用和设计改进等提供依据。本研究应用热平板仪、人工气候室等研究设备以及真人着装实验,对高低温作业典型工种常用的耐高温防护服和低温防护服的舒适性能进行了研究。研究结果显示,不同类型高、低温防护服的透气性、透湿性、着装压力、肢体活动角度等均表现出一定差异,防护服的面料、结构和工艺等均影响到其整体舒适性,并提出了相应的改善建议。     

The Effects of Local Cooling on Thermophysiological Response in Participants Wearing Dust-Free Garments

This study was designed to find the effects of two kinds of dust-free garments with (A) and without (B) frozen gel strip (FGS), and half-naked clothing (brassiere and shorts; C) on thermophysiological parameters and on temperature and humidity within clothing. The heart rate, rectal, and skin temperatures as well as sweat rate and clothing microclimate were measured during 140 min in 9 healthy females. Inquiries were also made into the subjective rating of thermal, humidity, and comfort sensations. The main findings in our experiments are as follows: (a) Physiological parameters such as rectal and skin temperatures (chest and forehead), heart rate, and sweat rate were clearly lowest in garb C, intermediate in garb A, and highest in garb B throughout the experiment; (b) Temperature and humidity within clothing were lower in garb A than in garb B; (c) More than half of the 9 participants decreased thermal sensation by wearing garb A. These results suggest that the usage of FGS could improve the heat load in lightly working participants wearing dust-free garments.     

防护服对消防员工效性能影响的定量研究*

为开发高性能防护服以提升救援效率,基于人体试验,测量受试者穿戴灭火防护服、半封闭防化服、全封闭防化服以及基础服装（对照组）时静态条件下左右手握力值、疲劳度（RPE）和活动受限程度,通过方差分析、接受者操作特征（ROC）曲线图、相关性分析进行定量研究。研究结果表明:灭火防护服对消防员工效性能影响大于防化服,灭火防护服较对照组握力减小32%、RPE增大54%、活动受限程度增大35倍,且RPE和活动受限程度均与握力呈显著负相关（p<0.001）。研究结果可为消防员个体防护服装设计、测试、性能提升等提供理论支撑,也可为消防员生命安全保障研究提供基础数据。     

常用高、低温防护服隔热性能研究

为评价常用类型高、低温防护服的防护性能,本研究应用热平板仪、人工气候室和暖体假人等研究设备,对高低温作业典型工种常用的耐高温防护服和低温防护服的隔热性能进行了研究。研究结果显示,不同类型高、低温防护服的服装面料、服装整体的隔热性表现出一定差异,模拟环境下的着装生理学测试结果也存在不同,防护服的面料、结构和工艺等均影响到其整体隔热性能。防护服装的全面评价通常涉及安全性、工效学特性等多个方面,有必要从服装的舒适性、工效学特性等方面进一步研究,并开展大规模的现场人体穿着实验,从而为高低温防护服的选用和设计改进等提供依据。     

Physiological Method of Evaluating Protective Clothing for Work in a Cold Environment

The purpose of this study was to determine the usefulness of physiological studies in the evaluation of protective clothing for work in a cold environment. The study included the examination of the dynamics of changes in chosen physiological parameters (core and skin temperatures, heart rate, pulmonary minute ventilation) as well as physical ones (the temperature and relative humidity under the clothes) during work in protective clothing with unknown thermal insulation. The experiment was conducted in extreme environmental conditions (–10 and –15°C) at a work load defined by the clothing manufacturer as moderate. Results show that thermal equilibrium was achieved and maintained throughout the investigated work time (60 min) and that the protective clothing ensures safety on the time scale of a regular 8-hour work day. It was also shown that the dynamics of thermal stress physiological parameters can be used to determine the maximum duration of exposure for cold protective clothing with unknown thermal insulation.     

The influence of sweating on the heat transmission properties of cold protective clothing studied with a sweating thermal manikin.

One of the objectives of the European SUBZERO project was to study the influence of sweat evaporation and condensation on the heat transmission properties of cold protective clothing. With the sweating thermal manikin Coppelius, water vapour transfer through and water condensation in the clothing can be determined simultaneously with the thermal insulation. In this study, 4 cold protective ensembles, intended for use temperatures between 0 and -50 degrees C, were measured with the dry manikin and at 2 different sweating rates. In addition, the ensembles were measured with non-sweating thermal manikins and in wear trials.     

Thermal strain in fire fighters while wearing task-fitted versus en 469:2005 protective clothing during a prolonged rescue drill.

Fire fighters are normally overprotected during their working hours because of the tendency to keep the personal protection level sufficiently high in case of the worst possible scenarios. This study investigated the effects of task-fitted protective clothing on thermal strain in fire fighters as compared to EN 469:2005 protective clothing during a prolonged (2 1/2 hrs) job-related rescue drill under neutral and hot climates. The subjects were 23 healthy, physically fit professional male fire fighters aged 26-44 years. Measurements included cardiovascular and thermal responses and subjective assessments. Wearing task-fitted clothing during rescue tasks in a neutral climate considerably reduced total thermal and cardiovascular strain in prolonged rescue work. The fire fighters also perceived physical work as significantly harder on average, and reported more intense subjective discomfort while wearing EN 469:2005 as compared to task-fitted clothing.     

Analytical Study of the Heat Loss Attenuation by Clothing on Thermal Manikins Under Radiative Heat Loads

For wearers of protective clothing in radiation environments there are no quantitative guidelines available for the effect of a radiative heat load on heat exchange. Under the European Union funded project ThermProtect an analytical effort was defined to address the issue of radiative heat load while wearing protective clothing. As within the ThermProtect project much information has become available from thermal manikin experiments in thermal radiation environments, these sets of experimental data are used to verify the analytical approach. The analytical approach provided a good prediction of the heat loss in the manikin experiments, 95% of the variance was explained by the model. The model has not yet been validated at high radiative heat loads and neglects some physical properties of the radiation emissivity. Still, the analytical approach provides a pragmatic approach and may be useful for practical implementation in protective clothing standards for moderate thermal radiation environments.     

Evaluation of a new ballistic vest design for compliance with Standard No. PN-V-87000:2011 using physiological tests

Research into newly developed ballistic vests to be worn by police officers under clothing was carried out with air temperature conditions of +20 °C. A ballistic vest should incorporate protective features, comfort and ergonomics. The thermal strain on users who wore the vests was evaluated as an average and individually, after they had been conditioned in high (+50 °C), low (?40 °C) or neutral (+20 °C) air temperatures, while performing various occupational activities. Research involved six police officers aged 36–42 years, who wore civilian clothing used in moderate environmental conditions. During the tests, physiological parameters (internal temperature, local skin temperatures and amount of sweat secreted) were determined. The ease of doing exercises while wearing the vests, vest service and level of discomfort in use were assessed. Research showed that the vests tested, both as an average and individually, meet the requirements of Standard No. PN-V-87000:2011 (clause 4.5).     

Thermal Strain in Fire Fighters While Wearing Task-Fitted Versus EN 469:2005 Protective Clothing During a Prolonged Rescue Drill

Fire fighters are normally overprotected during their working hours because of the tendency to keep the personal protection level sufficiently high in case of the worst possible scenarios. This study investigated the effects of task-fitted protective clothing on thermal strain in fire fighters as compared to EN 469:2005 protective clothing during a prolonged (2 1/2 hrs) job-related rescue drill under neutral and hot climates. The subjects were 23 healthy, physically fit professional male fire fighters aged 26–44 years. Measurements included cardiovascular and thermal responses and subjective assessments. Wearing task-fitted clothing during rescue tasks in a neutral climate considerably reduced total thermal and cardiovascular strain in prolonged rescue work. The fire fighters also perceived physical work as significantly harder on average, and reported more intense subjective discomfort while wearing EN 469:2005 as compared to task-fitted clothing.     

Assessing gait changes in firefighters due to fatigue and protective clothing

Each year, roughly 11,000 firefighters are injured as a result of slips, trips and falls, which account for over 25% of all fireground injuries. Wearing personal protective equipment (PPE) can increase risk of fall-related injuries due to its weight, restrictiveness, and increased heat stress. Modification of PPE may serve to mitigate firefighter injuries related to loss of balance and falls. We examined the effects of choosing ‘enhanced’ protective clothing (lightweight, breathable, and less restrictive compared to typical firefighting PPE) and simulated firefighting tasks (18-min bout over four activities) on subsequent gait performance. To assess the effect of wearing protective clothing and firefighting activity, seven gait parameters and three movement errors were assessed during level and obstacle-crossing walking tasks. Forty-four firefighters wore one of two types of PPE (‘Standard’, ‘Enhanced’) during three testing conditions (baseline in station uniform, pre-firefighting activity in PPE, and post-firefighting activity in PPE). The effect of donning any PPE was found to significantly impair gait performance. Fatigue may impact effective mobility since more movement errors were observed during post-activity than pre-activity assessments. Although the Enhanced PPE did not lead to any significant differences in gait parameters compared to Standard PPE, participants in Enhanced PPE made twice as many movement errors, potentially attributed to lack of familiarity with the gear. These results suggest that wearing firefighting PPE and heat-stress induced fatigue are associated with reduced gait performance and increased risk for tripping over obstacles.     

化学防护服的分类及选用

本文较为系统地介绍了化学防护服的分类方法、典型化学防护服的特点和适用场合及化学防护服选择应考虑的主要因素和一般程序,对化学防护服的选用具有一定的指导意义。     

服装行业缝纫工作工效学调查研究

对服装行业缝纫工种工人的慢性肌肉骨骼损伤进行了工效学分析。结果表明，目前缝纫工主要存在的工效学问题是：坐位工作台均偏高，工作椅也普遍较高，同一动作持续工作时间过长（平均大于１小时），８小时工作日休息时间过短（平均仅为３０分钟）。建议根据有关标准和法规，采取相应改进措施     

淋雨及不同温度条件对消防员防护服各部位热阻的影响

为了研究淋雨及不同温度条件对消防员防护服各部位热阻的影响,以消防防护服为研究对象,利用环境舱和暖体假人系统,在20 mm/h降雨强度和20~30 ℃的复合环境条件下,研究淋雨、不同温度复合环境对服装各部位热阻的影响。研究结果表明:淋雨过程中,服装热阻的变化趋势为先上升再下降最后趋于稳定;淋雨与不同温度复合环境会使得消防防护服热阻降低,其中影响较大的部位为上臂部、腹部、胸部、背部及臀部等。     

国外防护服技术的发展

近十几年来,国际上防护服技术发展非常迅速,主要表现在:国际性学术会议举行频繁;学术性团体相继成立;学术论文数量增加很快;新品种不断出现;市场形势看好。发展迅速的主要原因是:皮肤防护意识的加强;法规和标准化建设的推动;新型防护材料的发展;基础研究工作的深入。但就整体而言,防护服技术仍是一个比较年轻的处于初始阶段的学科,许多问题有待解决。预计近期内仍将是一种蓬勃发展的形势。