Evaluation of flow controllers used with evacuated canisters to assess VOC exposures in occupational and non-occupational environments.

Ideally, measuring exposures to volatile organic compounds should allow for modifying sampling duration without loss in sensitivity. Traditional sorbent-based sampling can vary sampling duration, but sensitivity may be affected when capturing shorter tasks. Diaphragm and capillary flow controllers allow for a range of flow rates and sampling durations for air sampling with evacuated canisters. The goal of this study was to evaluate the extent to which commercialized capillary flow controllers satisfy the bias (±10%) and accuracy (±25%) criteria for air sampling methods as established by the National Institute for Occupational Safety and Health (NIOSH) using the framework of ASTM D6246 Standard Practice for Evaluating the Performance of Diffusive Samplers to compare their performance with diaphragm flow controllers in a long-term field study. Phase 1 consisted of a series of laboratory tests to evaluate capillary flow controller flow rates with respect to variations in temperature (-15-24 °C). The results demonstrated a slight increase in flow rate with lower temperatures. In Phase 2, the capillary flow controller was evaluated utilizing a matrix of parameters, including time-weighted average concentration, peak concentration (50-100× base concentration), air velocity across the sampler inlet (0.41-0.5 m/s), relative humidity (20-80%), and temperature (10-32 °C). Comparison of challenge concentrations with reference concentrations revealed the aggregate bias and overall accuracy for four tested compounds to be within the range of criteria for both NIOSH and ASTM standards. Additionally, capillary flow controllers displayed lower variability in flow rate and measured concentration (RSD: 2.4% and 4.3%, respectively) when compared with diaphragm flow controllers (RSD: 6.9% and 7.2%, respectively) for 24-hr laboratory tests. Phase 3 involved further testing of flow rate variability for both diaphragm and capillary flow controllers in a field study. The capillary flow controller displayed a lower level of variability (RSD: 5.2%) than the diaphragm flow controller (RSD: 8.0%) with respect to flow rate, while allowing for longer durations of sampling.

International assessment results on non-NIOSH approved respirators by the national personal protective technology laboratory (NPPTL): a data note.

OBJECTIVES: Due to the COVID-19 pandemic and the shortage of the National Institute for Occupational Safety & Health (NIOSH)-approved N95 respirators, the Food and Drug Administration granted an Emergency Use Authorization to allow the use of non-NIOSH approved respirators provided that these respirators must undergo tests by a protocol of TEB-APR-STP-0059, similar methods of NIOSH standard testing procedure. This initiative safeguards the quality of respirators and the effectiveness of occupational protection. The dataset of all the testing results could benefit further analysis of COVID-19 infection rates in relation to different types of N95 respirators used and identify potential correlations of various test parameters in the testing system for validation. The analysis enhances understanding of the quality, effectiveness, and performance of N95 respirators in the prevention of respiratory infectious transmission and develops improved occupational safety measures. DATA DESCRIPTION: The dataset was transformed, transcribed, and compiled from the official testing data of non-NIOSH-approved N95 respirators reported in the NIOSH website under the Centers for the Disease Control and Prevention in the United States. The dataset included details of 7,413 testing results of N95 respirators (manufacturer, model, and maximum and minimum filtration efficiency) and test parameters (flow rate, initial filter resistance, and initial percent leakage). Supplementary items were added to increase the availability of data analysis and enhance the interpretability of the assessments of the quality of N95 respirators.

Comparison of multi-task ergonomic assessment methods for risk of upper extremity and low back musculoskeletal disorders.

Work-related musculoskeletal disorder of upper extremity multi-task assessment methods (Revised Strain Index [RSI], Distal Upper Extremity Tool [DUET]) and manual handling multi-task assessment methods (Revised NIOSH Lifting Equation [RNLE], Lifting Fatigue Failure Tool [LiFFT]) were compared. RSI and DUET showed a strong correlation (rs = 0.933, p < 0.001) where increasing risk factor exposure resulted in increasing outputs for both methods. RSI and DUET demonstrated fair agreement (κ = 0.299) in how the two methods classified outputs into risk categories (high, moderate or low) when assessing the same tasks. The RNLE and LiFFT showed a strong correlation (rs = 0.903, p = 0.001) where increasing risk factor exposure resulted in increasing outputs, and moderate agreement (κ = 0.574) in classifying the outputs into risk categories (high, moderate or low) when assessing the same tasks. The multi-task assessment methods provide consistent output magnitude rankings in terms of increasing exposure, however some differences exist between how different methods classify the outputs into risk categories.

Visualizing the NIOSH Pocket Guide: Open-source web application for accessing and exploring the NIOSH Pocket Guide to Chemical Hazards.

The NIOSH Pocket Guide to Chemical Hazards is a trusted resource that displays key information for a collection of chemicals commonly encountered in the workplace. Entries contain chemical structures-occupational exposure limit information ranging from limits based on full-shift time-weighted averages to acute limits such as short-term exposure limits and immediately dangerous to life or health values, as well as a variety of other data such as chemical-physical properties and symptoms of exposure. The NIOSH Pocket Guide (NPG) is available as a printed, hardcopy book, a PDF version, an electronic database, and a downloadable application for mobile phones. All formats of the NIOSH Pocket Guide allow users to access the data for each chemical separately, however, the guide does not support data analytics or visualization across chemicals. This project reformatted existing data in the NPG to make it searchable and compatible with exploration and analysis using a web application. The resulting application allows users to investigate the relationships between occupational exposure limits, the range and distribution of occupational exposure limits, and the specialized sorting of chemicals by health endpoint or to summarize information of particular interest. These tasks would have previously required manual extraction of the data and analysis. The usability of this application was evaluated among industrial hygienists and researchers and while the existing application seems most relevant to researchers, the open-source code and data are amenable to modification by users to increase customization.

Validation of N95 respirator models for pressure drop and particle capture efficiency.

Despite efforts to apply administrative and engineering controls to minimize worker exposure to aerosols, filtering facepiece respirators (FFRs) continue to be an important form of personal protective equipment in hard-to-control settings such as healthcare, agriculture, and construction. Optimizing the performance of FFRs can be advanced with the use of mathematical models that incorporate the forces that act on particles during filtration as well as those filter characteristics that influence filter pressure drop. However, a thorough investigation of these forces and characteristics using measurements of currently available FFRs has not been undertaken. Filter characteristics such as fiber diameter and filter depth were measured from samples taken from six currently-available N95 FFRs from three manufacturers. A filtration model was developed that included diffusion, inertial and electrostatic forces to estimate the filtration of an aerosol with a Boltzmann charge distribution. The diameter of the filter fibers was modeled as either a single "effective" diameter or as a lognormal distribution of diameters. Both modeling schemes produced an efficiency curve that simulated efficiency measurements made over a range of particle diameters (0.01 - 0.3 µm) with the use of a scanning mobility particle sizer in the region where efficiency is at a minimum. However, the method using a distribution of fiber diameters produced a better fit for particles > 0.1 µm. The coefficients associated with a simple form of the diffusion equation constituting a power law incorporating the Peclet number were adjusted to enhance model accuracy. Likewise, the fiber charge of the electret fibers was also adjusted to maximize model fit but remained within levels reported by others. A filter pressure drop model was also developed. Results demonstrated the need for a pressure drop model applicable to N95s relative to existing models developed with the use of fibers with larger diameters than those used in current N95 FFRs. A set of N95 FFR characteristics are provided that can be used to develop models of typical N95 FFR filter performance and pressure drop in future studies.

An analysis of suicides among first responders ─ Findings from the National Violent Death Reporting System, 2015-2017.

INTRODUCTION: First responders, including law enforcement officers (LEOs), firefighters, emergency medical services (EMS) clinicians, and public safety telecommunicators, face unique occupational stressors and may be at elevated risk for suicide. This study characterized suicides among first responders and identifies potential opportunities for additional data collection. METHODS: Using suicides identified from the three most recent years of National Violent Death Reporting System data with industry and occupation codes from the NIOSH Industry and Occupation Computerized Coding System (2015-2017), decedents were categorized as first responders or non-first responders based on usual occupation. Chi-square tests were used to evaluate differences in sociodemographic and suicide circumstances between first and non-first responders. RESULTS: First responder decedents made up 1% of all suicides. Over half of first responders (58%) were LEOs, 21% were firefighters, 18% were EMS clinicians, and 2% were public safety telecommunicators. Compared to non-first responder decedents, more first responders served in the military (23% vs. 11%) and used a firearm as the method of injury (69% vs. 44%). Among first responder decedents for whom circumstances were known, intimate partner problems, job problems, and physical health problems were most frequent. Some common risk factors for suicide (history of suicidal thoughts, previous suicide attempt, alcohol/substance abuse problem) were significantly lower among first responders. Selected sociodemographics and characteristics were compared across first responder occupations. Compared to firefighters and EMS clinicians, LEO decedents had slightly lower percentages of depressed mood, mental health problems, history of suicidal thoughts, and history of suicide attempts. CONCLUSIONS: While this analysis provides a small glimpse into some of these stressors, more detailed research may help inform future suicide prevention efforts and interventions. PRACTICAL APPLICATION: Understanding stressors and their relation to suicide and suicidal behaviors can facilitate suicide prevention among this critical workforce.

Fit evaluation of NIOSH approved N95 filtering facepiece respirators with various skin protectants: A pilot study.

Widespread disease outbreaks can result in prolonged wear times of National Institute for Occupational Safety and Health Approved N95 filtering facepiece respirators by healthcare personnel. Prolonged wear times of these devices can cause the development of various adverse facial skin conditions. Healthcare personnel have been reported to apply "skin protectants" to the face to reduce the pressure and friction of respirators. Because tight-fitting respirators rely on a good face seal to protect the wearer, it is important to understand if the fit is affected when skin protectants are used. This laboratory pilot study included 10 volunteers who performed quantitative fit tests to evaluate respirator fit while wearing skin protectants. Three N95 filtering facepiece respirator models and three skin protectants were evaluated. Three replicate fit tests were performed for each combination of subject, skin protectant (including a control condition of no protectant), and respirator model. Fit Factor (FF) was affected differently by the combination of the protectant type and respirator model. The main effects of the protectant type and respirator model were both significant (p < 0.001); additionally, their interaction was significant (p = 0.02), indicating FF is affected by the combined effects of the protectant type and respirator model. Compared to the control condition, using a bandage-type or surgical tape skin protectant decreased the odds of passing the fit test. Using a barrier cream skin protectant also decreased the odds of passing the fit test across all models compared to the control condition; however, the probability of passing a fit test was not statistically significantly different from the control condition (p = 0.174). These results imply that all three skin protectants reduced mean fit factors for all N95 filtering facepiece respirator models tested. The bandage-type and surgical tape skin protectants both reduced fit factors and passing rates to a greater degree than the barrier cream. Respirator users should follow respirator manufacturers' guidance on the use of skin protectants. If a skin protectant is to be worn with a tight-fitting respirator, the fit of the respirator should be evaluated with the skin protectant applied before use in the workplace.

Water consumption patterns impact hydration markers in males working in accordance with the National Institute for Occupational Safety and Health recommendations.

The impact of water consumption bolus volume and frequency on hydration biomarkers during work in the heat is unknown. In a randomized, crossover fashion, eight males consumed either 500 mL of water every 40 min or 237 mL of water every 20 min during 2 hr of continuous walking at 6.4 kph, 1.0% grade in a 34 °C/30% relative humidity environment, followed by 2 hr of rest. Hydration biomarkers and variables were assessed pre-work, post-work, and after the 2 hr recovery. There were no differences in body mass between trials at any time point (all p > 0.05). Percent change in plasma volume during work was not different when 237 mL of water was repeatedly consumed (-1.6 ± 8.2%) compared to 500 mL of water (-1.3 ± 3.0%, p = 0.92). Plasma osmolality was maintained over time (p = 0.55) with no difference between treatments (p = 0.21). When consuming 500 mL of water repeatedly, urine osmolality was lower at recovery (205 ± 108 mOsmo/L) compared to pre-work (589 ± 95 mOsmo/L, p < 0.01), different from repeatedly consuming 237 mL of water which maintained urine osmolality from pre-work (548 ± 144 mOsmo/L) through recovery (364 ± 261 mOsmo/L, p = 0.14). Free water clearance at recovery was greater with repeated consumption of 500 mL of water (1.2 ± 1.0 mL/min) compared to 237 mL of water (0.4 ± 0.8 mL/min, p = 0.02). Urine volume was not different between treatments post-work (p = 0.62), but greater after 2 hr of recovery when repeatedly consuming 500 mL of water compared to 237 mL (p = 0.01), leading to greater hydration efficiency upon recovery with repeated consumption of 237 mL of water (68 ± 12%) compared to 500 mL (63 ± 14%, p = 0.01). Thirst and total gastrointestinal symptom scores were not different between treatments at any time point (all p > 0.05). Body temperatures and heart rate were not different between treatments at any time point (all p > 0.05). Drinking larger, less frequent water boluses or drinking smaller, more frequent water boluses are both reasonable strategies to promote adequate hydration and limit changes in body mass in males completing heavy-intensity work in the heat.

Comparison of ACGIH lifting threshold limit values to validated low back disorder lifting assessment methods outcomes.

BACKGROUND: Work-related low back pain (LBP) increases the workforce disability and healthcare costs. This study evaluated the LBD risk level associated with handling the ACGIH TLVs in lifting tasks corresponding to various horizontal and vertical zones. OBJECTIVE: The aim of this study was to compare the low-risk ACGIH TLV to risk outcomes from various validated lifting assessment methods, including the OSU LBD Risk Model, NIOSH Lifting Equation, and LiFFT. METHODS: Twenty-four subjects were recruited for this study to perform various lifting conditions. The various ergonomic assessment methods were then used to obtain the risk assessment outcomes. RESULTS: The selected assessment methods showed that the ACGIH-defined TLVs are associated with less than high-risk for LBD for all the assessed tasks. The findings showed a moderate agreement (Kendall's W = 0.477) among the various assessment methods risk outcomes. The highest correlation (ρ= 0.886) was observed between the NIOSH Lifting Equation and LiFFT methods risk assessment outcomes. CONCLUSION: The findings showed that ACGIH-defined TLVs possesses less than high-risk for LBD. The outcomes of the selected ergonomic assessment methods moderately agree to each other.

A reevaluation of selected mortality risks in the updated NCI/NIOSH acrylonitrile cohort study.

Objectives: The study aimed to determine whether the National Cancer Institute's (NCI) recent suggestion of associations between acrylonitrile (AN) exposure and mortality in lung and bladder cancer and pneumonitis is robust to alternative methods of data analysis. Materials and methods: We used the Richardson method to indirectly adjust risk ratios (RRs) in relation to AN exposure for potential confounding by smoking and asbestos. We repeated key analyses omitting workers from Plant 4 to account for possible local, historical shipyard-related asbestos exposures. Results: The adjustment of lung cancer RRs for confounding by both smoking and asbestos and omitting Plant 4 workers yielded mostly decreased RRs and much less evidence of a positive association with cumulative AN exposure. Conclusion: Overall, our reanalysis provided little evidence to support NCI's suggestion of associations between AN exposure and mortality in lung and bladder cancer and pneumonitis.

Validation of the NIOSH Worker Well-Being Questionnaire in Italian Language.

OBJECTIVE: This study aimed to validate in Italian the Worker Well-Being Questionnaire developed by US National Institute for Occupational Safety and Health. METHODS: The questionnaire was independently translated into Italian by two authors. Translations were compared with obtain a synthesis that was back-translated. Back translations were submitted to an expert committee to produce a final version of the questionnaire. The Italian version, after being pretested, was administered guaranteeing anonymity to a total sample of 206 health care workers. RESULTS: Findings obtained are satisfactory, indicating excellent fit (CFI and TLI values ranged from 0.96 to 0.99, RMSEA values ranged from 0.03 to 0.07), sound internal consistency of scales (Cronbach's α values exceeded 0.7) and factor structures consistent with theory. CONCLUSIONS: Italian version of the questionnaire is faithful to the original and allows for efficient and robust measurement of workers' well-being.

Analyzing the potential environmental impact of NIOSH list of hazardous drugs (group 2).

For the first time, several pharmaceuticals have been defined as priority substances in the new proposal of the revision of the Water Framework Directive (WFD). Consequently, environmental quality standards have been determined for several drugs. This is the case with the antiepileptic carbamazepine, which is considered as hazardous in healthcare settings by The National Institute for Occupational Safety and Health (NIOSH). This organism considers as such drugs that have shown teratogenicity, carcinogenicity, genotoxicity or other developmental, reproductive, or organ toxicity at low doses in studies with animals or humans. This study has been focused on the non-carcinogenic drugs classified in group 2, and their presence in the environment. This group contains many different therapeutic agents such as antineoplastics, psychoactive drugs, immunosuppressants and antivirals, among others. Of the 116 drugs included in the list, 26 have been found in aquatic environmental matrices. Certain drugs have received most attention (e.g., the antiepileptic carbamazepine, progesterone and the antidepressant paroxetine) while others completely lack environmental monitoring. Carbamazepine, fluconazole, paroxetine and warfarin have been found in invertebrates' tissues, whereas carbamazepine, oxazepam and paroxetine have been found in fish tissues. The main aim of the NIOSH's hazardous drug list is to inform healthcare professionals about adequate protection measures to prevent occupational exposure to these pharmaceuticals. However, this list contains useful information for other professionals and researchers such as environmental scientists. The paucity of relevant environmental data of certain hazardous pharmaceuticals might be important to help in the prioritization of compounds that may demand further research.

Revised NIOSH lifting equation: a critical evaluation.

The revised NIOSH lifting equation (RNLE) aims to manage lifting-related lower back pain (LBP), by determining safe load limits. Many researchers have studied the multiplier development criteria, the universal applicability of the equation and its ability to identify an increased risk of LBP in lifting tasks. Although a number of strengths of the equation have been highlighted, many limitations have also been identified. The need for new multipliers, such as worker and environmental characteristics, was highlighted in order to make the equation more adaptable. The RNLE was designed to protect 75% of female workers and is therefore inherently conservative. Additionally, as all multipliers have values less than or equal to 1, the recommended weight limits (RWLs) can be further reduced. Thus, new multipliers may be defined, by combining two or more existing multipliers, to make the RWLs more realistic.

Predicting the load constant of the revised NIOSH lifting equation based on demographics.

Manual materials handling (MMH) and lifting activities have been identified as risk factors for lower back pain (LBP). Of the many tools available to analyse and design lifting tasks, the revised NIOSH lifting equation (RNLE) is perhaps the most widely used. However, the equation is based on data primarily from the West. To make the model universally applicable, the effect of worker characteristics like age, gender, weight and anthropometry on maximum acceptable weight limits (MAWLs) was studied. A psychophysical methodology was adopted to arrive at the MAWLs. In total, 58 industrial workers (30 men and 28 women) participated in the study. Based on the observations of the study, an equation was developed that would allow the RNLE load constant to be modified for different populations based on simple anthropometric data. The load constant for the Indian population was found to be comparable to the RNLE recommendations.

Evaluation of propylene glycol methyl ether as a potential challenge agent for leak detection of liquid and headspace from closed system drug transfer devices using Fourier transform infrared spectroscopy.

Choosing an appropriate surrogate of hazardous drugs for use in testing Closed System Drug-Transfer Devices (CSTDs) is a challenging endeavor with many factors that must be considered. It was suggested that the compound propylene glycol methyl ether (PGME) may meet many of the criteria we considered important in a suitable surrogate. Criteria included sufficient volatility to evaporate from aqueous liquid leaks efficiently, a Henry's constant which produced sufficient vapor phase concentrations to make headspace leaks detectable, and suitability for detection using a low-cost detection system. We evaluated the measurement of vapors from solutions containing PGME released inside a closed chamber. We present data used to quantify limits of detection, limits of quantification, bias, precision, and accuracy of Fourier Transform Infrared Spectroscopy (FTIR) measurements of vapors from 2.5 M PGME solutions. The effects of ethanol as a component of the PGME solution were also evaluated. Liquid drops of PGME solutions and headspace vapors above PGME solutions were released to simulate leaks from CSTDs. Using a calibration apparatus, an instrumental limit of detection (LOD) of 0.25 ppmv and a limit of quantitation (LOQ) of 0.8 ppmv were determined for PGME vapor. A LOD of 1.1 µL and a LOQ of 3.5 µL were determined for liquid aliquots of 2.5 M PGME solution released in a closed chamber. Accurate quantitation of liquid leaks required complete evaporation of droplets. With the upper end of the useable quantitation range limited by slow evaporation of relatively large droplets and the lower end defined by the method LOQ, the method evaluated in this research had a narrow quantitative range for liquid droplets. Displacement of 45 mL of vial headspace containing PGME vapor is the largest amount expected when using the draft NIOSH testing protocol. Release of an unfiltered 45 mL headspace aliquot within the NIOSH chamber was calculated to produce a concentration of 0.8 ppmv based on the Henry's constant, which is right at the instrumental LOQ. Therefore, the sensitivity of the method was not adequate to determine leaks of PGME vapor from a headspace release through an air filtering CSTD when using the draft NIOSH testing protocols with an FTIR analyzer.

Do the National Institute for Occupational Safety and Health recommendations for working in the heat prevent excessive hyperthermia and body mass loss in unacclimatized males?

The National Institute for Occupational Safety and Health recommendations for work in the heat suggest workers consume 237 mL of water every 15-20 min and allow for continuous work at heavy intensities in hot environments up to 34 °C and 30% relative humidity. The goal was to determine whether the National Institute for Occupational Safety and Health recommendations prevented core temperature from exceeding 38.0 °C and greater than 2% body mass loss during heavy-intensity work in the heat. Eight males consumed 237 mL of water every 20 min during 2 hr of continuous heavy-intensity walking (6.4 kph, 1% grade) in a 34 °C/30% relative humidity environment, in accordance with the National Institute for Occupational Safety and Health recommendations. Projected core temperature and percent body mass loss were calculated for 4 and 8 hr of continuous work. Core temperature rose from baseline (36.8 ± 0.3 °C) to completion of 2 hr of work (38.1 ± 0.6 °C, p < 0.01), with two participants reaching the 38.0 °C threshold. Projected core temperatures remained elevated from baseline (p < 0.01), did not change from 2 to 4 hr (38.1 ± 0.7 °C, p > 0.99) and 4 to 8 hr (38.1 ± 0.8 °C, p > 0.99), respectively, and one participant exceeded 38.0 °C at 4 to 8 hr. There was no change in body mass loss over time (p > 0.99). During 2 hr of continuous heavy-intensity work in the heat, 75% of participants did not reach 38 °C core temperature and 88% did not reach 2% body mass loss when working to National Institute for Occupational Safety and Health recommendations.

Response to NIOSH Request for Information on Interventions to Prevent Work-Related Stress and Support Health Worker Mental Health.

The root causes of health care worker strain and depression include excessive job demands, extended work schedules, little decision-making opportunity, assault, bullying, and fear of injury. Potential links between working conditions and opioid overuse have also been discussed, beginning with psychological job strain or with physical pain leading to medication use. Promising solutions have been identified and many would be cost-effective, as enhanced working conditions could improve workers' mental health, job satisfaction, retention, and patient outcomes. Considering the number of health care workers leaving work during the global COVID-19 pandemic, it is urgent to address preventable root causes. In 2021, the US Congress called for educating health workers and first responders on the primary prevention of mental health conditions and substance use disorders. The CDC issued a Request for Information; this submission summarized research from CPH-NEW, a NIOSH Center of Excellence in Total Worker Health®, supplemented by a selective literature review.

Review and demonstration of equations applied to models of filtering facepiece respirator particle capture efficiency.

The use of filtering facepiece respirators (FFRs) of various types increased dramatically by both workers and the public during the ongoing COVID-19 pandemic. This increased use has, likewise, instigated a proliferation of research on the qualities of FFRs. An aspect of FFR development and optimization involves the use of mathematical models that predict filter efficiency based on various filter characteristics while also considering a number of particle capture forces. An evaluation of current literature failed to identify a publication that provides a comprehensive assessment of the models developed to predict filter efficiency. The purpose of this review was, therefore, to describe models developed to include the forces associated with diffusion, interception, impaction, and electrostatic attraction as they contribute to the efficiency of an entire filter. The literature review was augmented with figures created with the use of many of the models discussed to compare different models of the same force as well as to illustrate the influence of electrostatic forces on overall filter efficiency.