Self-contained Breathing Apparatus Research Articles

Effects of packaging methods and temperature variations on the quality and microbial diversity of grouper (Epinephelus Lanceolatus) during cold storage

Microbial growth and its metabolism are the primary reasons for fish spoilage. In this study, the effects of temperature fluctuations and modified atmosphere packaging (MAP) on the quality and microbial diversity of grouper (Epinephelus lanceolatus) during cold storage were investigated. Fish fillets were packed in air packaging (AP), vacuum packaging (VP), MAP1 (40% CO2/55% N2/5% O2), and MAP2 (60% CO2/35% N2/5% O2), and stored at T1 (4 °C) and T2 (4–8 °C temperature fluctuations), respectively. Total viable counts (TVC), psychrophilic bacteria count, Pseudomonas count, and H2S-producing bacteria count all increased during cold storage. Pseudomonas, Serratia, and Carnobacterium were the dominant genera in AP, VP, and MAP2 at T1 storage, with relative abundances of 82.7%, 54.5%, and 57.3%, respectively. Temperature fluctuations accelerated the spoilage process of the grouper, and increased the relative abundance of Serratia in the samples, but had less effect on the composition of these spoilage bacterial members. The microbial community was more affected by the different gas atmospheres. MAP inhibited the growth of Pseudomonas and increased the relative abundance of Carnobacterium and Psychrobacter in the samples. Low temperature and MAP effectively suppressed the rise of pH, total volatile basic nitrogen (TVB-N), trimethylamine (TMA), thiobarbituric acid reactive substances (TBARs), and K values and maintained the water holding capacity (WHC) and sensory quality of the samples. Grouper had the longest shelf life under MAP2-T1 treatment. The MAP2-T1 samples maintained lower levels of TVB-N (151.8 mg/kg), TMA (7.6 mg/kg), TBARs (0.90 mg MDA/kg), and K value (48.5%) and higher levels of WHC (77.6%) on the 18th day, with a lower degree of spoilage compared to other samples.

A Sustainable Material for Sheep's Cheese Wedges Stored under Different Atmosphere Conditions.

This study is based on the need to improve packaging sustainability in the food industry. Its aim was to assess the performance of a recyclable plastic material for semi-hard sheep's cheese wedges packaging as an alternative to conventional non-sustainable plastic materials. Four different packaging treatments (air, vacuum, and CO2/N2 gas mixtures 50/50 and 80/20% (v/v)) were studied. Changes in gas headspace composition, sensory properties, cheese gross composition, weight loss, pH, colour, and texture profile were investigated at 5 ± 1 °C storage for 56 days. The sensory analysis indicated that vacuum packaging scored the worst in paste appearance and holes, and air atmosphere the worst in flavour; it was concluded that cheeses were unfit from day 14-21 onwards. Air and vacuum packaging were responsible for most of the significant changes identified in the texture profile analysis, and most of these happened in the early stages of storage. The colour parameters a* and b* differentiated the air packaging from the rest of the conditions. As in previous studies using conventional plastic materials, modified atmosphere packaging, either CO2/N2 50/50 or 80/20% (v/v), was the most effective preserving technique to ensure the quality of this type of cheese when comparing air and vacuum packaging treatments.

Thermal degradation of self-contained breathing apparatus facepiece lenses under radiant thermal loads

The self-contained breathing apparatus is one of the most critical components of the firefighting personal protective ensemble providing protection from potentially toxic gases and products of combustion. Three models of self-contained breathing apparatus facepiece lenses meeting various editions of national standards were exposed to radiant thermal loads of 5, 10, 15, and 20 kW/m2 until thermal degradation resulted in hole formation or the test duration reached 30 min. Thermal damage was documented as time to crazing, bubbling, and hole formation. Temperature was recorded within the facepiece. There were significant differences in times to thermal damage between lenses. The facepiece lens model meeting the 2013 edition of National Fire Protection Association 1981 had significantly longer times to thermal degradation than those meeting older editions of the standard. Maximum temperatures were higher in the facepiece model meeting the 2013 edition of National Fire Protection Association 1981, likely because of the extended time the radiant load was applied.

Determination of dynamic air gap thickness and analysis of its relationship with firefighters’ joint movement

ABSTRACT Objectives. The purpose of this study was to calculate the dynamic air gap thickness between the human body and the turnout gear. Relationships between the air gap thickness and joint range of motion (ROM) were also explored. Methods. The air gap thickness and joint ROM of 12 male firefighters walking in a control condition with no self-contained breathing apparatus (SCBA) and three varying-strapped SCBAs were measured using three-dimensional (3D) body scanning and 3D inertial motion capture. The interpolation technique was employed to predict the air gap thickness curve during walking. The dynamic air gap thickness was compared with the joint ROM to see how they relate to the location and percentage of movement restriction. Results. During the walking, the air gap fluctuated as a sine curve. Carrying SCBA reduced the air gap thickness at the trunk most (F = 11.17, p < 0.001, η 2 = 0.63), and adjusting the shoulder strap length altered the air gap distribution at the trunk. The reduced air gap at the pelvis caused an incremental restriction on pelvis rotation. Conclusions. A compatibility design of the shoulder strap and hip belt in SCBA with the turnout jacket is suggested.

Oxy-Inflammation in Humans during Underwater Activities.

Underwater activities are characterized by an imbalance between reactive oxygen/nitrogen species (RONS) and antioxidant mechanisms, which can be associated with an inflammatory response, depending on O2 availability. This review explores the oxidative stress mechanisms and related inflammation status (Oxy-Inflammation) in underwater activities such as breath-hold (BH) diving, Self-Contained Underwater Breathing Apparatus (SCUBA) and Closed-Circuit Rebreather (CCR) diving, and saturation diving. Divers are exposed to hypoxic and hyperoxic conditions, amplified by environmental conditions, hyperbaric pressure, cold water, different types of breathing gases, and air/non-air mixtures. The "diving response", including physiological adaptation, cardiovascular stress, increased arterial blood pressure, peripheral vasoconstriction, altered blood gas values, and risk of bubble formation during decompression, are reported.

Application of bacteriophage MS2 in preliminary simulation of inactivation rate of pathogenic viruses in commercial beef and chicken packaging

SummaryIn response to the growing concern of transmitting pathogenic viruses through food, this research aimed to assess the impact of various factors on the commercial packaging of meat (chicken and beef) on the inactivation of bacteriophage MS2 which was scrutinised by examining the influence of packaging type, bacteriophage spiking levels, temperature, as well as the meat shape and type. The findings revealed that the recovery of bacteriophage MS2 from minced beef was lower in modified atmosphere packaging (MAP) compared with air packaging (AP) at both storage times, spiking levels, and freezing and refrigerating temperatures. On the other hand, the recovery of the bacteriophage from chopped beef was lower in AP than in MAP in refrigerating conditions at both spiking levels during the 3 days of storage. According to our findings, the recovery levels of bacteriophage MS2 from chicken had statistically significant differences in both packaging types at different spiking levels. Storage conditions and packaging type were the most essential parameters in bacteriophage MS2 viability. The lowest bacteriophage viability belonged to MAP.

Effects of modified atmosphere packaging (MAP) on quality and shelf life of dried spotted snakehead (Channa punctatus) products using an improved solar dryer

This study focused on follow-up the changes in the quality and shelf life of dried spotted snakehead (Channa punctatus) products under modified atmosphere packaging (MAP) conditions processed using an improved solar dryer. Four packaging methods, such as, air pack (sealed without changing atmospheric gas), MAP-1 (100% N2), MAP-2 (50% CO2 &amp; 50% N2) and MAP-3 (40% CO2, 30% O2 &amp; 30% N2) were employed and kept at room temperature. Biochemical and microbial analyses were performed at 15-days intervals over a period of 4 to 5 months of room storage. Moisture of the dried products remained within acceptable limits considering the salt content of the products. Observations revealed comparatively lower pH, total volatile base nitrogen (TVB-N), and thiobarbituric acid reactive substance (TBARS) values, none of which crossed the acceptable limits in any of the packaging conditions. Total viable counts (TVC) exceeded the permissible level of 5 log CFUg-1 after 75 days for air pack and MAP-1 samples and 120 days for MAP-2 and MAP-3 samples. Based on the bacterial counts, the shelf life of dried spotted snakehead products was estimated at approximately 75 days for air-pack and MAP-1 samples and 120 days for MAP-2 &amp; MAP-3 samples. Therefore, MAP-2 (50% CO2 &amp; 50% N2) &amp; MAP-3 (40% CO2, 30% O2 &amp; 30% N2) were identified as effective packaging methods for extending the shelf life of dried spotted snakehead products.

Determinants of stair climbing speeds in volunteer firefighters

Stair climb is a physically demanding task for firefighters and plays an important role in firefighting. Yet little is known about factors affecting the speed of firefighters on stairs. The aims of this study were to quantify stair climbing speeds in firefighting and to establish the relationship between multiple factors and stair performance of firefighters. A convenience sample of sixty-three volunteer firefighters (30.4 ± 8.2 years; BMI 26.2 ± 4.2 Kg/m2) performed stair climb exercises under different conditions: without additional equipment, with Personal Protective Equipment (PPE), with PPE and Self-Contained Breathing Apparatus (SCBA), and with PPE and SCBA while carrying a tool (e.g., axe, hose, Halligan, etc.). The observed climbing rates of the SCBA and Tool conditions align with earlier studies. Multiple Linear Regression (MLR) analysis revealed that the combination of extrinsic factors (covered distance and equipment weight) along with intrinsic factors (gender, age, Body Mass Index and handrail use) significantly explained 37 % of the variance in ascent speed and 23 % of the variance in descent speed of firefighters. Overall males exhibited faster speeds and older age, higher BMI, and longer distances lead to slower speeds. Equipment weight was found to be the most substantial individual predictor on stair performance in firefighters. For example, carrying an extra load equivalent to 30 % of body mass resulted in a decrease of 24.8 % and 17.6 % in ascent and descent speed respectively. These findings may contribute to improve fire safety engineering analysis and firefighting operations.

Dynamics of pH at Santa Catalina Island

The local expression of ocean acidification may depend on local oceanographic features in addition to global forcings. Our objective is to provide a baseline of pH behavior at Santa Catalina Island, situated within the unique oceanographic characteristics of the Southern California Bight, and to gain insight into ocean acidification at the island. Measurements of the upper water column (to 30-m depth) of pH, temperature, conductivity, chlorophyll and dissolved oxygen at Santa Catalina were made from a fixed mooring and by profiling the water column from a boat and on Self-Contained Underwater Breathing Apparatus (SCUBA). The average pH (8.095 at 18-m depth) was found to be higher than that reported off the nearby mainland and the Northern Channel Islands. The higher value is thought to result from both downwelling produced by internal waves as well as less upwelling at the island compared to other locations. Large modulations in pH at depth corresponded to advection of gradients by internal waves. Within the accuracy of the sensors there was no seasonal dependence detected at near-surface, nor a pH signal associated with the sub-surface chlorophyll and oxygen maxima. We conclude that marine life living at depths affected by internal waves experience significant variation in pH.

Evaluation of Work Efficiency in Structural Firefighters.

Langford, EL, Bergstrom, HC, Lanham, S, Eastman, AQ, Best, S, Ma, X, Mason, MR, and Abel, MG. Evaluation of work efficiency in structural firefighters. J Strength Cond Res 37(12): 2457-2466, 2023-To perform occupational tasks safely and effectively, firefighters (FF) must work quickly and consume air provided by the self-contained breathing apparatus (SCBA) efficiently. However, most literature only factors work rate into performance, neglecting the inherent time limitation imposed by the SCBA. The purpose of this article was to (a) evaluate the reliability and variability in a "work efficiency" (WE) performance metric reflective of both work rate and air consumption; (b) explore the relationship between WE and established measures of metabolic strain; and (c) identify fitness, anthropometric, and demographic correlates of WE. About 79 structural FF completed an air consumption drill while breathing through an SCBA. Self-paced work duration and air consumption were entered into the WE equation. A subsample of FF (n = 44) completed another randomized trial while breathing through a portable gas analyzer. Anthropometric and fitness data were collected separately. Correlations were performed between WE vs. fitness, anthropometric, demographic, and metabolic outcomes. Multiple linear regression was used to identify the strongest predictors of WE. WE was reliable (intraclass correlation coefficient = 0.71) and yielded inter-FF variability {0.79 ± 0.25 ([lb·in-2·min]-1) × 104; coefficient of variation = 31.6%}. WE was positively correlated to oxygen consumption (V̇O2) (L·minute-1, mL·kg-1·minute-1) and tidal volume and negatively correlated to V̇E/V̇O2 and respiratory frequency. Height, upper-body endurance, and aerobic endurance were identified as the strongest predictors of WE (adjusted R2 = 0.59, RMSE = 0.16). WE is a reliable and occupationally relevant method to assess FF performance because it accounts for work rate and air consumption. Firefighters may enhance WE through a training intervention focused on improving metabolic tolerance, upper-body endurance, and aerobic endurance.

Polymer Characterization of Submerged Plastic Litter from Lake Tahoe, United States.

Monitoring plastic litter in the environment is critical to understanding the amount, sources, transport, fate, and environmental impact of this pollutant. However, few studies have monitored plastic litter on lakebeds which are potentially important environments for determining the fate and transport of plastic litter in freshwater basins. In this study, a self-contained underwater breathing apparatus was used for litter collection at the lakebed along five transects in Lake Tahoe, United States. Litter was brought to the surface and characterized by litter type. Plastic litter was subsampled, and polymer composition was determined using attenuated total reflection Fourier transform infrared spectroscopy. The average plastic litter from the lakebed for the five dive transects was 83 ± 49 items per kilometer. The top plastic litter categories were other plastic litter (plastic litter that did not fall in another category), followed by food containers, bottles <2 L, plastic bags, and toys. These results are in line with prior studies on submerged litter, and intervention approaches or ongoing education are needed. The six polymers most frequently detected in the subsamples were polyvinyl chloride, polystyrene/expanded polystyrene, polyethylene terephthalate/polyester, polyethylene, polypropylene, and polyamide. These observations reflect global plastic production and microplastic studies from lake surface water and sediments. We found that some litter subcategories were primarily comprised of a single polymer type, therefore, in studies where the polymer type cannot be measured but litter is categorized, these results could provide an estimate of the total polymer composition for select litter categories.

Evaluation of Air Quality inside Self-Contained Breathing Apparatus Used by Firefighters

(1) Background: When a fire breaks out, combustibles are burned and toxic substances such as carbon monoxide (CO), polycyclic aromatic hydrocarbons (PAH), benzene, and hydrogen cyanide are produced. The purpose of this study is to evaluate the air quality inside self-contained breathing apparatus (SCBA) by comparing it to that in the environment where the SCBA charger is installed. (2) Methods: The design of this study was a simulation-based case-control experiment study, and the experiment was conducted at two fire stations located on land and on water. When charging the SCBA, it was differentiated according to the presence or absence of exposure to harmful substances and the degree of exposure. The air quality inside the SCBA in the charging room installed in the fire station garages located on land and in the water, which were not completely isolated from harmful substances, was evaluated. CO, carbon dioxide (CO2), water, and oil mist were measured and analyzed to determine the air quality inside the SCBA. (3) Results: In the case of land firefighting stations, the mean CO among the SCBA internal air quality items was 20 times higher than the outside the SCBA, and higher than the safe range in the group with the highest exposure at the sites of firefighting buildings completely isolated from hazardous substances. The CO levels of all items of water were analyzed to be higher than the safe range in the floating fire station. (4) Conclusions: It was confirmed that the installation environment of an SCBA charging room can affect the safety of the charged internal air quality components. The results of this study can be actively used for the operation and management of SCBA charging room environments when building firefighting buildings in the future for the hygiene, safety, and health of firefighters.

The use of dive computers in forensic investigations of fatal breath-hold diving accidents: a case study.

Freediving is a type of diving in which divers rely solely on how long they can hold their breath underwater during their dive, which is why it can also be referred to as 'breath-hold diving'. Unlike scuba (self-contained underwater breathing apparatus) diving, individuals do not require training or licencing to perform freediving and may not be aware of the risks of this activity. This paper presents a case in which coastguards retrieved a free diver's lifeless body from the seafloor. In most cases such as this, the deceased individual's cause of death would be ruled as drowning. With the deceased diver's dive computer, we concluded that a shallow water blackout caused him to drown. Data from the dive computer were extracted, graphed, and analysed to explain how a skilled swimmer and diver drowned on one of his seemingly ordinary diving trips. The dive computer can be the sole witness to a fatal dive event and provide invaluable information to forensic scientists since the diver is almost always alone. To our knowledge of the available literature, dive computers have been used in scuba diving fatality investigations; however, we believe that they have not been used in death investigations of breath-hold divers. Deficient or hasty conclusions are often based solely on autopsy findings without data collected by diving technicians and investigators. It is crucial to wait to draw conclusions until all possible dive information has been gathered and studied. This study discusses the deficiency in presenting a reasonable idea to the grieving family and friends of how their beloved relative could have drowned even though he was known to be a fit and skilled diver and avid swimmer.

A biomechanical evaluation of firefighters’ musculoskeletal loads when carrying self-contained breathing apparatus in walking and running

Introduction: Musculoskeletal loading data are needed to design ergonomic intervention for firefighters. This study aimed to quantify the firefighters’ musculoskeletal loads during self-contained breathing apparatus (SCBA) carriage and evaluate the effectiveness of shoulder strap length variation for the prevention of SCBA-related injuries. Method: Twelve firefighters (height: 174.6 ± 2.4 cm, mass: 67 ± 3.5 kg, BMI = 22 ± 1 kg/m2) participated the walking and running protocols with no SCBA equipped and three varying-strapped SCBAs conditions. Joint range of motion and surface electromyography (sEMG) were synchronously measured. Subsequently, joint kinematics was inputted for subject-specific musculoskeletal modeling to estimate muscle forces and joint reaction forces, while the sEMG was used to validate the model. Repeated measures analysis of variance was used for the main effects (p < 0.05). Independent samples t-test was performed to determine differences between walking and running. Results: Walking with SCBA increased the rectus femoris force and hip reaction force by 34.92% [F = 53.629; p < 0.001; η2 = 0.317] and 34.71% [F = 53.653; p < 0.001; η2 = 0.517], the growth rate was 54.2% [F = 76.487; p < 0.001; η2 = 0.418] and 51.19% [F = 69.201; p < 0.001; η2 = 0.652] during running, respectively. Running with SCBA significantly increased the knee reaction force by 63.04% [F = 83.960; p < 0.001; η2 = 0.797], while only 18.49% increase during walking. Adjusting SCBA shoulder strap length significantly altered the rectus abdominis force and L4/L5 reaction force during walking and running. Conclusions: Results revealed that rectus femoris activity, hip and knee exertion was sensitive to SCBA carriage. The variation of shoulder strap length has potential to influence the risk of low back pain (LBP). Practical applications: The findings suggest that fire services promote targeting physical training at firefighters’ hip and knee regions. Test firefighters in this study were not advisable to adjust their shoulder strap at loose-fitting condition. The compatibility design of the trunk morphology and SCBA back-mounted frame was suggested for the management of LBP.

Application of Failure Mode and Effect Analysis and Fault Tree Analysis in Determining Prevention Efforts Failure of The Fire Extinguishing Process

Banyumas is one of the regencies that still experiences frequent fires. The fire caused physical or material losses. To minimize fire losses, many efforts can be made to prevent the occurrence of these potential causes, which are the cause of the failure of the firefighting process. This study aims to implement the Failure Mode and Effect Analysis (FMEA) and Fault Tree Analysis (FTA) methods in determining efforts to prevent fire suppression failures. The result of the FMEA is Risk Priority Number (RPN) values to assess critical potential causes that need to be analyzed using FTA. In this research, there are ten important causes of potential, namely burned assets, difficult assets to save, victims panicking, witnesses/owners were not present, officers slipping, water sources being far from the location, victims being rescued too late, victims being trapped, officers being hit by debris, and officers inhaled excess smoke (congested). The result FTA obtained eleven minimum cut sets, which can fail the firefighting process in the Banyumas Regency, namely lack of awareness from related agencies, the protection system is not up to the firefighting standard and lack of maintenance of the fire protection system, lack of knowledge about how to evacuate yourself, the water source is far from the location, the owner does not live in the place (location), the victim has responsibility for the assets saved, high-priority asset value, a witness has not reported because the incident is considered to be handled by the residents, fire smoke is thick and firefighters not using self-contained breathing apparatus (SCBA).

Firefighting: intensive training and improvement in air consumption in self-contained breathing apparatus (SCBA)

This article presents a research done with Military Firemen who have passed through a three-week intensive firefighting training. Developed by the authors, it was applied an air consumption measurement protocol during the use of the self-contained breathing apparatus (SCBA), fundamental firefighting equipment, before and after that period. It was noticed that the air comsuption was considerably improved with the intensive training program, for the three different types of effort (light, medium and high) that was established.

Development of Biscuit Products from Coffee Cherry Pulp

ABSTRACT The objective of this study was to investigate the potential application of coffee cherry pulp to produce biscuit products. The biscuit containing the cherry or cascara pulp were studied in terms of consumer acceptance, hardness, and chemical and microbiological characteristics under three different storage conditions, including vacuum packaging, air packaging, and air packaging plus 20% moisture content. Among all levels of replacement, biscuits supplemented with 10% cascara pulp, 25% butter, and 75% margarine provided the highest preferences in odor, flavor, and overall acceptance. Increasing cascara pulp provided a softer texture and more dietary fiber, protein, and chlorogenic acid content in the cascara biscuits (p < 0.05). Approximately, 4.58 g dietary fiber, 7.53 g protein, and 1.63 g chlorogenic acid was found in biscuits with 20% cascara pulp, 75% butter, and 25% margarine. Vacuum packaging was found to be necessary to maintain the quality of the biscuit and resist microbial growth during storage.

A multiple parameters fusion model based on hydrogen sulfide for accurately evaluating the freshness of lamb meat

SummaryHydrogen sulfide (H2S), as an important freshness indicator of meat, can effectively reflect the degree of spoilage. However, establishing a multiple parameters fusion model with temperature correction to fit the relationship between the H2S concentration and other freshness indicators is still a challenge. In this study, the M. longissimus thoracis et lumborum muscle (LTL) of lamb was stored in air packaging at 0 °C, 4 °C, 8 °C, 12 °C and 25 °C, respectively, to monitor the changes of gaseous H2S and other fresh indicators. The correlation analysis indicates that H2S concentration is highly consistent with lamb meat freshness. During the analysis, the well‐fitted Stirling models show high statistical relationships between H2S and total viable count (TVC)/total volatile base nitrogen (TVB‐N) values with the determination coefficients (R2) all exceeding 0.9000. Subsequently, the fusion freshness prediction models with the temperature corrections were successfully established by fusing the exponential models into the Stirling models. As verified, the fusion freshness prediction models based on H2S concentration can offer accurate predictions of the TVC and TVB‐N values of lamb meat at different temperatures with an R2 of 0.9352 and 0.8627, respectively. The proposed models might be used to accurately forecast and evaluate the freshness of meat in the process of storage.

Effect of Packaging System and Storage Conditions on Quality Retention of Shelled Walnut

Present study was carried out during 2017 and 2018 at Post-harvest laboratory of ICAR-Central Institute of Temperate Horticulture, Srinagar to assess the effect of packaging condition and storage period on shelled walnut Kernels for enhancing shelf life and retaining quality of shelled walnut. A total of 6 treatments (Traditional air packaging+light, Traditional air packaging+dark, Vacuum packaging+light, Vacuum packaging+dark, Vacuum packaging+Oxygen absorber+light, Vacuum packaging+Oxygen absorber+dark) were applied on shelled walnut kernels. Various observation on sensory attributes, change in fat content, and changes in a physiological loss in weight, firmness, and colour coordinates (kernel L*, a*, b*) was recorded at 0 days and 4 months, 8 months and 12 months. These sensory attributes and overall acceptability score revealed that the overall acceptability of walnut kernels was recorded as highest in T5 and slightly astringent in T6. The maximum decrease in fat content was also recorded in T1 followed by T2 and the least in T6 as the storage period advances similarly firmness index decreases as the storage interval increases in a similar pattern. The maximum mean increase in physiological loss in weight was observed in T1 followed by T2 and least in T6 as the storage period advances.The findings of this study revealed that at 12 months of the storage period, vacuum packaging+Oxygen absorber+Dark retained maximum shelf life and maintains the post-harvest quality as compared to traditional air packaging+light. Hence, walnut kernels could be stored in T6-Vacuum packaging+Oxygenabsorber+dark storage condition for maintaining the quality of walnut kernels for up to 12 months.

Exposure to polycyclic aromatic hydrocarbons assessed by biomonitoring of firefighters during fire operations in Germany.

Firefighters are exposed to a variety of hazardous substances including carcinogens such as polycyclic aromatic hydrocarbons (PAH) during firefighting. In order to minimize the uptake of such substances into the body, firefighters wear personal protective equipment. Only few data exist from real-life firefighting missions and under common although highly variable exposure scenarios such as fighting fires in residential buildings, outdoor, and vehicle fires. The aim of this study is to assess the levels of 1-Hydroxypyrene (1-OHP) as marker for incorporated PAH during firefighting operations in Germany using biomonitoring methods. We analyzed urine samples for 1-OHP from 77 firefighters who reported firefighting operations (with and without creatinine adjustment). Urine samples were collected before (baseline) and, where applicable, after firefighting operations at three time points subsequent (2-4, 6-8, and 12h). Compared to the baseline measurements, mean 1-OHP concentrations after firefighting missions were doubled (0.14 vs. 0.31μg/L urine, 0.13μg/g vs. 0.27μg/g creatinine) and this increase was observed 2-4h after firefighting. Firefighting in residential buildings (N=54) and of outdoor and vehicle fires (N=17) occurred most frequently, whereas blazes, vegetation fires, and fires in underground facilities (N=6) were rarely encountered. For residential building fires, a 3-fold increase in mean 1-OPH concentrations was observed, whereas no increase could be observed for outdoor and vehicle fires. The highest increase was observed for firefighters with interior attack missions (0.11μg/L vs. 0.48μg/L 1-OHP) despite the use of self-contained breathing apparatus (SCBA). During the suppression of outdoor or vehicle fires using SCBA, again, no increase was observed. Although PAH are taken up during certain firefighting missions, the 1-OHP levels almost entirely remained (in 64 of the 77 reported missions) within the normal range of the German general population, i.e., below the reference levels (95th percentiles) of smokers (0.73μg/g creatinine) and non-smokers (0.30μg/g creatine). Under study conditions, properly applied protective clothing and wearing of SCBA led to a significant reduction of PAH exposure levels. But there are individual situations in which PAH are increasingly incorporated since the incorporation depends on several factors and can be extremely variable. In contrast to many workplaces with high occupational exposure levels, firefighters are not exposed to PAH on a daily basis. Nevertheless, the possibility of an individual increased cancer risk for a particular firefighter cannot completely be ruled out.