Local effects of printed logos and reflective striping fixed to firefighter clothing material packages under low radiation exposure.

Notifications that related 1st degree burns to reflective striping and impermeable clothing elements did reach the investigators, while the mechanisms behind this phenomenon are still unclear. Material tests for thermal and evaporative resistance, and for heat transmission under dry and wet conditions at low radiation levels were done to evaluate the performance of protective clothing with and without printed logos or reflective striping. The results under the specified conditions showed reduction of heat loss capacity under impermeable elements from dry to wet conditions. Reflective surfaces, even when more impermeable, showed still lower heat transmission through the textile package than materials without striping under tested moisture and radiation combinations. It can be expected that the reported 1st degree burns were related to clothing design and tightness/fit rather than to reflective striping. However, due to the fine balance between clothing thermal and evaporative resistance, outer material emissivity, moisture quantity and location in clothing and applied radiation level, a different setup could lead to different results.

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.

The Protective Performance of Process Operators' Protective Clothing and Exposure Limits under Low Thermal Radiation Conditions.

During the early stage of a fire, a process operator often acts as the first responder and may be exposed to high heat radiation levels. The present limit values of long- (>15 min) and short-term exposure (<5 min), 1.0 and 1.5 kW/m2, respectively, have been set using physiological models and manikin measurements. Since human validation is essentially lacking, this study investigated whether operators' protective clothing offers sufficient protection during a short-term deployment. Twelve professional firefighters were exposed to three radiation levels (1.5, 2.0, and 2.5 kW/m2) when wearing certified protective clothing in front of a heat radiation panel in a climatic chamber (20 °C; 50% RH). The participants wore only briefs (male) or panties and a bra (female) and a T-shirt under the operators' clothing. Skin temperatures were continuously measured at the chest, belly, forearm, thigh, and knee. The test persons had to stop if any skin temperature reached 43 °C, at their own request, or when 5 min of exposure was reached. The experiments showed that people in operators' clothing can be safely exposed for 5 min to 1.5 kW/m2, up to 3 min to 2.0 kW/m2, and exposure to 2.5 kW/m2 or above must be avoided unless the clothing can maintain an air gap.

Evaluation of a Wearable Non-Invasive Thermometer for Monitoring Ear Canal Temperature during Physically Demanding (Outdoor) Work.

Aimed at preventing heat strain, health problems, and absenteeism among workers with physically demanding occupations, a continuous, accurate, non-invasive measuring system may help such workers monitor their body (core) temperature. The aim of this study is to evaluate the accuracy and explore the usability of the wearable non-invasive Cosinuss° °Temp thermometer. Ear canal temperature was monitored in 49 workers in real-life working conditions. After individual correction, the results of the laboratory and field study revealed high correlations compared to ear canal infrared thermometry for hospital use. After performance of the real-life working tasks, this correlation was found to be moderate. It was also observed that the ambient environmental outdoor conditions and personal protective clothing influenced the accuracy and resulted in unrealistic ear canal temperature outliers. It was found that the Cosinuss° °Temp thermometer did not result in significant interference during work. Therefore, it was concluded that, without a correction factor, the Cosinuss° °Temp thermometer is inaccurate. Nevertheless, with a correction factor, the reliability of this wearable ear canal thermometer was confirmed at rest, but not in outdoor working conditions or while wearing a helmet or hearing protection equipment.

Skin Barrier Impairment due to the Occlusive Effect of Firefighter Clothing.

At fire scenes, firefighters are exposed to potentially harmful substances. Besides inhalation of these products, also skin contamination and the risk of dermal absorption is getting more attention. In this perspective, skin barrier impairment due to the occlusive effect of firefighter clothes could enhance the risk of penetration of hazardous substances. The effect of a firefighter jacket and cellophane on the skin was studied in a paired comparison involving 16 volunteers. Biophysical parameters were measured before, immediately after and 30 min after ending the occlusion. Reflectance confocal microscopy was used to study the skin morphology. Immediately after wearing a firefighter jacket, Transepidermal Water Loss values were significantly increased. This is an indication of an occlusive effect of the firefighter jacket. The skin barrier was fully restored after 30 min after occlusion with cellophane or wearing a firefighter jacket.

Maximum allowable exposure to different heat radiation levels in three types of heat protective clothing.

To determine safe working conditions in emergency situations at petro-chemical plants in the Netherlands a study was performed on three protective clothing combinations (operator's, firefighter's and aluminized). The clothing was evaluated at four different heat radiation levels (3.0, 4.6, 6.3 and 10.0 k∙W∙m-2) in standing and walking posture with a thermal manikin RadMan™. Time till pain threshold (43°C) is set as a cut-off criterion for regular activities. Operator's clothing did not fulfil requirements to serve as protective clothing for necessary activities at heat radiation levels above 1.5 k∙W∙m-2 as was stated earlier by Den Hartog and Heus1). With firefighter's clothing it was possible to work almost three min up to 4.6 k∙W∙m-2. At higher heat radiation levels firefighter's clothing gave insufficient protection and aluminized clothing should be used. Maximum working times in aluminized clothing at 6.3 k∙W∙m-2 was about five min. At levels of 10.0 k∙W∙m-2 (emergency conditions) emergency responders should move immediately to lower heat radiation levels.

A test battery related to ergonomics of protective clothing.

Specialised protective clothing, such as that worn by firefighters, is usually tested only to standards which give requirements for the materials used (e.g. EN469). However, this testing often neglects the effect the manufacturing process of the garment has on the material properties, the effects of clothing design, sizing and fit, as well as the interaction of the clothing with other components of the standard gear for the profession. Such effects can only be tested by looking at the protective gear as a whole. This paper deals with methods to do additional testing on protective garments with firefighter clothing as example. In other words, methods which go beyond EN469. Human subject tests for physiological load, heat protection, ergonomic design, loss of performance, rain/moisture protection and conspicuity/visibility of the clothing are described and proposed for evaluation of protective clothing in general and for further development of standards on firefighters' clothing.

Influence of inspiratory resistance on performance during graded exercise tests on a cycle ergometer.

Due to more stringent requirements to protect personnel against hazardous gasses, the inspiratory resistance of the present generation of respiratory protective devices tends to increase. Therefore an important question is to what extent inspiratory resistance may increase without giving problems during physical work. In this study the effects of three levels (0.24; 1.4 and 8.3 kPa s l(-1)) of inspiratory resistance were tested on maximal voluntary performance. Nine male subjects performed a graded exercise test on a cycle ergometer with and without these three levels of inspiratory resistance. Oxygen consumption, heart rate, time to exhaustion and external work were measured. The results of these experiments showed that increasing inspiratory resistance led to a reduction of time to exhaustion (TTE) on a graded exercise test(GXT). Without inspiratory resistance the mean TTE was 11.9 min, the three levels of resistance gave the following mean TTE's: 10.7, 7.8 and 2.7 min. This study showed that TTE on a GXT can be predicted when physical fitness (VO2-max) of the subject and inspiratory resistance are known. The metabolic rate of the subjects was higher with inspiratory resistance, but no differences were found between the three selected inspiratory loads. Other breathing parameters as minute ventilation, tidal volume, expiration time and breathing frequency showed no or minor differences between the inspiratory resistances. The most important conclusion of these experiments is that the overall workload increases due to an increase in inspiratory resistance by wearing respiratory protective devices.

The effect of rowing headgear on forced convective heat loss and radiant heat gain on a thermal manikin headform.

Both radiant and forced convective heat flow were measured for a prototype rowing headgear and white and black cotton caps. The measurements were performed on a thermal manikin headform at a wind speed of 4.0 m . s(-1) (s = 0.1) in a climate chamber at 22.0 degrees C (s = 0.05), with and without radiant heat flow from a heat lamp, coming from either directly above (90 degrees ) or from above at an angle of 55 degrees . The effects of hair were studied by repeating selected measurements with a wig. All headgear reduced the radiant heat gain compared with the nude headform: about 80% for the caps and 95% for the prototype rowing headgear (P < 0.01). Forced convective heat loss was reduced more by the caps (36%) than by the prototype rowing headgear (9%) (P < 0.01). The radiant heat gain contributed maximally 13% to the net heat transfer, with or without headgear, showing that forced convective heat loss is the dominant heat transfer parameter under the chosen conditions. The results of the headgear - wig combinations were qualitatively similar, with lower absolute heat transfer.

Moisture accumulation in sleeping bags at - 7 degrees C and - 20 degrees C in relation to cover material and method of use.

Moisture accumulation in sleeping bags during extended periods of use is detrimental to thermal comfort of the sleeper, and in extreme cases may lead to sleep loss and hypothermia. As sub-zero temperatures were expected to affect vapour resistance of microporous membranes, the effect of using semipermeable and impermeable rain covers for sleeping bags on the accumulation of moisture in the bags during 6 days of use at - 7 degrees C and 5 days at - 20 degrees C were investigated. In addition, the routine of shaking off hoarfrost from the inside of the cover after the sleep period as a preventive measure for moisture accumulation was studied. Moisture accumulation (ranging from 92 to 800 grams) was found to be related to the vapour resistance of the materials used. The best semipermeable material gave the same moisture build-up as no cover at - 7 degrees C, though build-up increased substantially at - 20 degrees C. Shaking off the hoarfrost from the inside of the cover after each use was beneficial in preventing a high moisture build-up. It was concluded that semi-permeable cover materials reduce moisture accumulation in sleeping bags at moderate sub-zero temperatures, but in more extreme cold (- 20 degrees C) the benefits are reduced in comparison to routinely shaking frost from impermeable covers. Compared to fixed impermeable covers, the benefits of all semi-permeable covers are large. For long-term use without drying facilities, the differences observed do favour the semi-permeable covers above impermeable ones, even when regularly removing the hoarfrost from the inside in the latter.