Evaluation of dust respirators for elimination of mouse aeroallergens

The efficiency of various dust respirators for eliminating mouse allergens [mouse urine proteins (MUP), pelts proteins (MPP) and serum albumin (MSA)] were evaluated with use of low-volume air samplers and immunochemical methods. Three kinds of dust respirators from one manufacturer which have different efficacy in the exclusion of dust particles were put on the fiber glass filter in each air sampler. Then the air in a mouse housing room was sampled. The allergens passed through the respirators, were trapped in the fiber glass filters, and then extracted from the filters. The allergens of MUP and MPP in the extract were measured by an inhibition method of fluorometric enzyme-linked immunosorbent assay (ELISA) for IgE antibody and those of MSA measured by a fluorometric sandwich ELISA. The respirator with the lowest capability of exclusion was found to eliminate 65-86% of respective allergens. The other two respirators with higher powers eliminated 98% of MUP. MPP and MSA were eliminated to undetectable levels through these respirators. This study provided a means for the evaluation of dust respirators for animal aeroallergens.     

COVID-19 global pandemic planning: Dry heat incubation and ambient temperature fail to consistently inactivate SARS-CoV-2 on N95 respirators

The ongoing pandemic of the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has placed a substantial strain on the supply of personal protective equipment, particularly the availability of N95 respirators for frontline healthcare personnel. These shortages have led to the creation of protocols to disinfect and reuse potentially contaminated personal protective equipment. A simple and inexpensive decontamination procedure that does not rely on the use of consumable supplies is dry heat incubation. Although reprocessing with this method has been shown to maintain the integrity of N95 respirators after multiple decontamination procedures, information on the ability of dry heat incubation to inactivate SARS-CoV-2 is largely unreported. Here, we show that dry heat incubation does not consistently inactivate SARS-CoV-2-contaminated N95 respirators, and that variation in experimental conditions can dramatically affect viability of the virus. Furthermore, we show that SARS-CoV-2 can survive on N95 respirators that remain at room temperature for at least five days. Collectively, our findings demonstrate that dry heat incubation procedures and ambient temperature for five days are not viable methods for inactivating SARS-CoV-2 on N95 respirators for potential reuse. We recommend that decontamination procedures being considered for the reuse of N95 respirators be validated at each individual site and that validation of the process must be thoroughly conducted using a defined protocol.     

Cardiorespiratory effects of respiratory protective devices during exercise in well-trained men

The effects of a filtering device, an air-line breathing apparatus and a self-contained breathing apparatus ( SCBA ) on pulmonary ventilation, oxygen consumption and heart rate were studied in 12 well-trained firemen aged 21-35 years. Their average maximal oxygen consumption (VO2 max) was 64.9 ml X min-1 X kg-1. Sequential tests without and with the respirator were performed on a treadmill. The continuous test contained five components, each of which lasted 5 min: sitting at rest, walking at 20%, 40%, and 60% of the individual VO2 max, and recovery sitting. During the higher submaximal work levels and recovery, ventilation, heart rate, and oxygen consumption in particular increased more with respirators than without them. At the highest work level the increments in oxygen consumption caused by the respirators were 13%, (8.7 ml X min-1 X kg-1), 7% (4.4 ml X min-1 X kg-1), and 20% (12.7 ml X min-1 X kg-1) of VO2 max. All three respirators hampered respiration, resulting in hypoventilation. The additional effort of breathing and the weight of the apparatus (15 kg with the SCBA ) increased the subjects' cardiorespiratory strain so clearly that the need for rest periods and the individual's work capacity when the respirators are worn must be carefully considered, particularly with the SCBA .     

Impact of Low Filter Resistances on Subjective and Physiological Responses to Filtering Facepiece Respirators

Ten subjects underwent treadmill exercise at 5.6 km/h over one hour while wearing each of three identical appearing, cup-shaped, prototype filtering facepiece respirators that differed only in their filter resistances (3 mm, 6 mm, and 9 mm H₂O pressure drop). There were no statistically significant differences between filtering facepiece respirators with respect to impact on physiological parameters (i.e., heart rate, respiratory rate, oxygen saturation, transcutaneous carbon dioxide levels, tympanic membrane temperature), pulmonary function variables (i.e., tidal volume, respiratory rate, volume of carbon dioxide production, oxygen consumption, or ventilation), and subjective ratings (i.e., exertion, thermal comfort, inspiratory effort, expiratory effort and overall breathing comfort). The nominal filter resistances of the prototype filtering facepiece respirators correspond to airflow resistances ranging from 2.1 - 6.6 mm H₂O/L/s which are less than, or minimally equivalent to, previously reported values for the normal threshold for detection of inspiratory breathing resistance (6 - 7.6 mm H₂O/L/sec). Therefore, filtering facepiece respirators with filter resistances at, or below, this level may not impact the wearer differently physiologically or subjectively from those with filter resistances only slightly above this threshold at low-moderate work rates over one hour.     

COVID-19 global pandemic planning: Performance and electret charge of N95 respirators after recommended decontamination methods

Shortages of N95 respirators for use by medical personnel have driven consideration of novel conservation strategies, including decontamination for reuse and extended use. Decontamination methods listed as promising by the Centers for Disease Control and Prevention (CDC) (vaporous hydrogen peroxide (VHP), wet heat, ultraviolet irradiation (UVI)) and several methods considered for low resource environments (bleach, isopropyl alcohol and detergent/soap) were studied for two commonly used surgical N95 respirators (3M™ 1860 and 1870+ Aura™). Although N95 filtration performance depends on the electrostatically charged electret filtration layer, the impact of decontamination on this layer is largely unexplored. As such, respirator performance following decontamination was assessed based on the fit, filtration efficiency, and pressure drop, along with the relationship between (1) surface charge of the electret layer, and (2) elastic properties of the straps. Decontamination with VHP, wet heat, UVI, and bleach did not degrade fit and filtration performance or electret charge. Isopropyl alcohol and soap significantly degraded fit, filtration performance, and electret charge. Pressure drop across the respirators was unchanged. Modest degradation of N95 strap elasticity was observed in mechanical fatigue testing, a model for repeated donnings and doffings. CDC recommended decontamination methods including VHP, wet heat, and UV light did not degrade N95 respirator fit or filtration performance in these tests. Extended use of N95 respirators may degrade strap elasticity, but a loss of face seal integrity should be apparent during user seal checks. NIOSH recommends performing user seal checks after every donning to detect loss of appropriate fit. Decontamination methods which degrade electret charge such as alcohols or detergents should not be used on N95 respirators. The loss of N95 performance due to electret degradation would not be apparent to a respirator user or evident during a negative pressure user seal check.     

Fitting Characteristics of N95 Filtering-Facepiece Respirators Used Widely in China

Background

Millions of people rely on N95 filtering facepiece respirators to reduce the risk of airborne particles and prevent them from respiratory infections. However, there are no respirator fit testing and training regulations in China. Meanwhile, no study has been conducted to investigate the fit of various respirators. The objective of this study was to investigate whether people obtained adequate fit when wearing N95 filtering facepiece respirators (FFRs) used widely in China.

Methods

Fifty adult participants selected using the Chinese respirator fit test panel donned 10 common models of N95 FFRs. Fit factors (FF) and inward leakage were measured using the TSI PortaCount Plus. Each subject was tested with three replications for each model. A subject was considered to pass the fit test when at least two of the three FFs were greater than 100. Two models were conducted fit tests before and after training to assess the role of training.

Results

The geometric mean FFs for each model and trained subjects ranged from <10 to 74.0. The fifth percentile FFs for only two individual respirator models were greater than 10 which is the expected level of performance for FFRs. The passing rates for these two models of FFRs were 44.7% and 20.0%. The passing rates were less than 10.0% for the other eight models. There were 27 (54%) participants who passed none of the 10 FFRs. The geometric mean FFs for both models when the subjects received training (49.7 and 74.0) were significantly larger than those when the same group of subjects did not receive any training (29.0 and 30.9) (P<0.05).

Conclusions

FFRs used widely in China should be improved according to Chinese facial dimensions. Respirator users could benefit from respirator training and fit testing before using respirators.     

Professional and home-made face masks reduce exposure to respiratory infections among the general population

Background

Governments are preparing for a potential influenza pandemic. Therefore they need data to assess the possible impact of interventions. Face-masks worn by the general population could be an accessible and affordable intervention, if effective when worn under routine circumstances.

Methodology

We assessed transmission reduction potential provided by personal respirators, surgical masks and home-made masks when worn during a variety of activities by healthy volunteers and a simulated patient.

Principal Findings

All types of masks reduced aerosol exposure, relatively stable over time, unaffected by duration of wear or type of activity, but with a high degree of individual variation. Personal respirators were more efficient than surgical masks, which were more efficient than home-made masks. Regardless of mask type, children were less well protected. Outward protection (mask wearing by a mechanical head) was less effective than inward protection (mask wearing by healthy volunteers).

Conclusions/Significance

Any type of general mask use is likely to decrease viral exposure and infection risk on a population level, in spite of imperfect fit and imperfect adherence, personal respirators providing most protection. Masks worn by patients may not offer as great a degree of protection against aerosol transmission.     

Principles and practice for SARS-CoV-2 decontamination of N95 masks with UV-C

A mainstay of personal protective equipment during the coronavirus disease 2019 pandemic is the N95 filtering facepiece respirator. N95 respirators are commonly used to protect healthcare workers from respiratory pathogens, including the novel coronavirus severe acute respiratory syndrome coronavirus 2, and are increasingly employed by other frontline workers and the general public. Under routine circumstances, these masks are disposable, single-use items, but extended use and reuse practices have been broadly enacted to alleviate critical supply shortages during the coronavirus disease 2019 pandemic. Although extended-time single use presents a low risk of pathogen transfer, repeated donning and doffing of potentially contaminated masks presents increased risk of pathogen transfer. Therefore, efficient and safe decontamination methods for N95 masks are needed to reduce the risk of reuse and mitigate local supply shortages. Here, we review the available literature concerning use of germicidal ultraviolet-C (UV-C) light to decontaminate N95 masks. We propose a practical method for repeated point-of-use decontamination using commercially available UV-C cross-linker boxes from molecular biology laboratories to expose each side of the mask to 800–1200 mJ/cm² of UV-C. We measure the dose that penetrated to the interior of the respirators and model the potential germicidal action on coronaviruses. Our experimental results, in combination with modeled data, suggest that such a UV-C treatment cycle should induce a >3-log-order reduction in viral bioburden on the surface of the respirators and a 2-log-order reduction throughout the interior. We find that a dose 50-fold greater does not impair filtration or fit of 3M 8210 N95 masks, indicating that decontamination can be performed repeatedly. As such, UV-C germicidal irradiation is a practical strategy for small-scale point-of-use decontamination of N95s.     

SNORKEL TRACHEOTOMY TUBE FOR RESPIRATOR USE

The Snorkel tracheotomy tube, a simple modification of the standard tube, overcomes many of the mechanical inconveniences usually encountered in the care of patients with tracheotomy who have to be kept in respirators. With it in place, it is not necessary to use special devices to hold the collar of the respirator away from the site of the tracheal incision. Nursing care of the patient is made easier.     

The Performance of Respirators Used in the Treatment of Respiratory Insufficiency

Mechanical ventilators may be required for the treatment of inadequate ventilation, intractable left heart failure and cerebral edema. Each situation requires different ventilator characteristics. The performance of the Blease P3, Engström, Mörch Piston, Bird Mark 7 and 8 and Bennett PR1 and PR2 respirators has been studied. The factors governing choice of respirator in specific clinical situations are described.     

Development of a Test System To Evaluate Procedures for Decontamination of Respirators Containing Viral Droplets

The aim of this study was to develop a test system to evaluate the effectiveness of procedures for decontamination of respirators contaminated with viral droplets. MS2 coliphage was used as a surrogate for pathogenic viruses. A viral droplet test system was constructed, and the size distribution of viral droplets loaded directly onto respirators was characterized using an aerodynamic particle sizer. The sizes ranged from 0.5 to 15 μm, and the sizes of the majority of the droplets were the range from 0.74 to 3.5 μm. The results also showed that the droplet test system generated similar droplet concentrations (particle counts) at different respirator locations. The test system was validated by studying the relative efficiencies of decontamination of sodium hypochlorite (bleach) and UV irradiation with droplets containing MS2 virus on filtering facepiece respirators. It was hypothesized that more potent decontamination treatments would result in corresponding larger decreases in the number of viable viruses recovered from the respirators. Sodium hypochlorite doses of 2.75 to 5.50 mg/liter with a 10-min decontamination period resulted in approximately 3- to 4-log reductions in the level of MS2 coliphage. When higher sodium hypochlorite doses (≥8.25 mg/liter) were used with the same contact time that was used for the dilute solutions containing 2.75 to 5.50 mg/liter, all MS2 was inactivated. For UV decontamination at a wavelength of 254 nm, an approximately 3-log reduction in the level of MS2 virus was achieved with dose of 4.32 J/cm² (3 h of contact time with a UV intensity of 0.4 mW/cm²), while with higher doses of UV irradiation (≥7.20 J/cm²; UV intensity, 0.4 mW/cm²; contact times, ≥5 h), all MS2 was inactivated. These findings may lead to development of a standard method to test decontamination of respirators challenged by viral droplets.During an infectious disease outbreak widespread panic can result from a limited understanding of the transmission route. Although some research points to a larger role for droplet nuclei (21, 28), other research suggests that droplets are the principal means of transmitting respiratory infections (10, 26). Droplets containing an infectious microorganism are believed to be transmitted to individuals who directly inhale the droplets resulting from coughing by carriers in close proximity or who ingest droplets spread to the mouth or the nose via the hands (7, 15). Large droplets were first defined as droplets more than 100 μm in diameter by Wells (30). Elsewhere, however, droplets more than 5 μm (23) or 10 μm (8) in diameter are often treated as large droplets. In this paper, the term “viral droplet” refers to all virus-containing liquid particles that retain their original size without significant evaporation, regardless of their specific size.N95 filtering facepiece respirators (FFRs) are routinely employed to prevent exposure of workers to biological hazards such as severe acute respiratory syndrome, tuberculosis, and novel H1N1 influenza A (6). In addition to CDC interim guidance (6), a recent report from the National Academies'' Institute of Medicine suggests that healthcare workers who are in close contact with individuals with novel H1N1 influenza illnesses should use fit-tested N95 respirators to reduce the risk of infection (18). This report also recommends increased research on influenza transmission and respiratory protection, which would enable policy makers to update these types of recommendations as additional disease prevention data become available.Current best practices suggest that once an FFR is worn in the presence of an infected patient, it should be considered potentially contaminated and discarded (5). However, during a pandemic outbreak a shortage of FFRs could occur (4). According to another report from the Institute of Medicine, during a 42-day influenza pandemic outbreak over 90 million N95 FFRs will be needed to protect workers in the healthcare sector (4). Furthermore, this report suggested that FFR reuse following decontamination should be considered a possible solution to deal with anticipated FFR shortages. Low-temperature biological decontamination methods have been suggested as a possible solution, but additional research needs to be done to determine whether infectious organisms can survive the decontamination process and if the decontamination method changes respirator fit (29).While it is well known that droplets play a role in the transmission of some respiratory infections, there is a lack of knowledge and data on the effectiveness of decontamination methods applied to respirators and porous personal protective equipment. There are several test methods for evaluation of the effectiveness of decontamination procedures for liquids and for hard porous or nonporous surfaces when they are challenged with viruses (2, 3, 27), while other methods are used to assess the effectiveness of decontamination procedures for FFRs when they are challenged with viral droplet nuclei (12). However, there is no test method to evaluate the effectiveness of biological decontamination procedures for disposable FFRs after they are challenged with viral droplets (liquid droplets containing a virus) whose sizes are similar to the sizes of droplets expelled by humans.Therefore, the aim of the present study was to develop a test system to evaluate the effectiveness of procedures for decontamination of respirators contaminated with viral droplets. The system was validated using two possible decontamination strategies: sodium hypochlorite and UV irradiation. It was hypothesized that the more potent decontamination treatments would result in corresponding larger decreases in the number of viable viruses recovered from the respirators than the less aggressive treatments.     

A method to determine the available UV-C dose for the decontamination of filtering facepiece respirators

Aims: To develop a method to assess model‐specific parameters for ultraviolet‐C (UV‐C, 254 nm) decontamination of filtering facepiece respirators (FFRs). Methods and Results: UV‐C transmittance was quantified for the distinct composite layers of six N95 FFR models and used to calculate model‐specific α‐values, the percentage of the surface UV‐C irradiance available for the internal filtering medium (IFM). Circular coupons, excised from the FFRs, were exposed to aerosolized particles containing MS2 coliphage and treated with IFM‐specific UV‐C doses ranging from 38 to 4707 J m^?2. Models exposed to a minimum IFM dose of 1000 J m^?2 demonstrated at least a 3 log reduction (LR) in viable MS2. Model‐specific exposure times to achieve this IFM dose ranged from 2 to 266 min. Conclusions: UV‐C transmits into and through FFR materials. LR of MS2 was a function of model‐specific IFM UV‐C doses. Significance and Impact of the Study: Filtering facepiece respirators are in high demand during infectious disease outbreaks, potentially leading to supply shortages. Reuse of disposable FFRs after decontamination has been discussed as a possible remediation strategy, but to date lacks supporting scientific evidence. The methods described here can be used to assess the likelihood that UV‐C decontamination will be successful for specific FFR models.     

Effects of relative humidity and spraying medium on UV decontamination of filters loaded with viral aerosols

Although respirators and filters are designed to prevent the spread of pathogenic aerosols, a stockpile shortage is anticipated during the next flu pandemic. Contact transfer and reaerosolization of collected microbes from used respirators are also a concern. An option to address these potential problems is UV irradiation, which inactivates microbes by dimerizing thymine/uracil in nucleic acids. The objective of this study was to determine the effects of transmission mode and environmental conditions on decontamination efficiency by UV. In this study, filters were contaminated by different transmission pathways (droplet and aerosol) using three spraying media (deionized water [DI], beef extract [BE], and artificial saliva [AS]) under different humidity levels (30% [low relative humidity {LRH}], 60% [MRH], and 90% [HRH]). UV irradiation at constant intensity was applied for two time intervals at each relative humidity condition. The highest inactivation efficiency (IE), around 5.8 logs, was seen for DI aerosols containing MS2 on filters at LRH after applying a UV intensity of 1.0 mW/cm(2) for 30 min. The IE of droplets containing MS2 was lower than that of aerosols containing MS2. Absorption of UV by high water content and shielding of viruses near the center of the aggregate are considered responsible for this trend. Across the different media, IEs in AS and in BE were much lower than in DI for both aerosol and droplet transmission, indicating that solids present in AS and BE exhibited a protective effect. For particles sprayed in a protective medium, RH is not a significant parameter.     

Mathematical Modeling of the Effectiveness of Facemasks in Reducing the Spread of Novel Influenza A (H1N1)

On June 11, 2009, the World Health Organization declared the outbreak of novel influenza A (H1N1) a pandemic. With limited supplies of antivirals and vaccines, countries and individuals are looking at other ways to reduce the spread of pandemic (H1N1) 2009, particularly options that are cost effective and relatively easy to implement. Recent experiences with the 2003 SARS and 2009 H1N1 epidemics have shown that people are willing to wear facemasks to protect themselves against infection; however, little research has been done to quantify the impact of using facemasks in reducing the spread of disease. We construct and analyze a mathematical model for a population in which some people wear facemasks during the pandemic and quantify impact of these masks on the spread of influenza. To estimate the parameter values used for the effectiveness of facemasks, we used available data from studies on N95 respirators and surgical facemasks. The results show that if N95 respirators are only 20% effective in reducing susceptibility and infectivity, only 10% of the population would have to wear them to reduce the number of influenza A (H1N1) cases by 20%. We can conclude from our model that, if worn properly, facemasks are an effective intervention strategy in reducing the spread of pandemic (H1N1) 2009.     

Biological monitoring of benzene exposure during maintenance work in crude oil cargo tanks

We investigated the association between the individual concentrations of benzene in the breathing zone and the concentrations of benzene in the blood and urine among workers maintaining crude oil cargo tanks. Benzene exposure was measured during three consecutive 12h work days among 13 tank workers and 9 unexposed referents (catering section). Blood and urine samples were collected pre-shift on the first day, post-shift on the third day, and pre-next shift on the following morning. The workers used half-mask air-purifying respirators, but not all workers used these systematically. The individual geometric mean benzene exposure in the breathing zone of tank workers over 3 days was 0.15 ppm (range 0.01-0.62 ppm). The tank workers' post-shift geometric mean benzene concentrations were 12.3 nmol/l in blood and 27.0 nmol/l in urine versus 0.7 nmol/l for both blood and urine among the referents. Benzene in the work atmosphere was highly correlated with the internal concentration of benzene both in post-shift blood (r=0.87, P<0.001) and post-shift urine (r=0.90, P<0.001), indicating that the varying use of respirators did not explain much of the variability in absorbed benzene. The results showed that, despite low benzene exposure in this work atmosphere and the use of personal protective equipment to a varying degree, the tank workers had a significant uptake of benzene that correlated highly with benzene exposure. The internal concentration of benzene was higher than expected considering the measured individual benzene exposure, probably due to an extended work schedule of 12h and physical strain during tank work. Control measures should be improved for processes, which impose a potential for increased absorption of benzene upon the workers.     

Severe Tetanus: Its Complications and Management

When phenothiazines and barbiturates fail to control the spasms of tetanus, total paralysis induced by muscle relaxants may be the only way of keeping the patient alive. The hazards of this technique are illustrated in this report of a patient with severe tetanus who was totally paralyzed for 26 days. Cardiac arrest, ileus, atelectasis, anemia, and limb contractures were among the problems dealt with. Devoted nursing care, an experienced medical team, respirators, minute ventilation meters, an airway pressure alarm, a hypothermia unit, a cardiac monitor pacemaker and facilities for determining blood-gas tensions were all necessary in the successful treatment of this patient. It is suggested that patients with severe tetanus should be transferred, under anesthesia and artificially ventilated, to hospitals possessing all these facilities.     

Medical surveillance of allergy in laboratory animal handlers

Allergic disease is a serious occupational health concern for individuals who have contact with laboratory animals. The principal respiratory symptoms include allergic rhinitis, conjunctivitis, and asthma. Urticaria (" hives") is the most common skin manifestation. The overall prevalence of allergic disease among laboratory animal handlers is about 23%, and respiratory allergy is much more common than skin allergy. Various studies have found annual incidence rates ranging from 2% to 12%. Prevention of animal allergy depends on control of allergenic material in the work environment. Personal protective equipment such as air filtering respirators should be used in addition to the other exposure control technologies where conditions require. Pre-placement evaluation and periodic medical surveillance of workers are important pieces of the overall occupational health program. The emphasis of these medical evaluations should be on counseling and early disease detection. The article gives recommendations for the content of the medical evaluations.     

Prognosis in Tetraplegia

A total of 141 cases of traumatic tetraplegia were admitted to the Liverpool Paraplegic Centre between 1947 and 1967. Most of the deaths occurred within three months of injury, and comparison with other centres suggests that the early mortality could be reduced by more use of mechanical respirators.Urological complaints and pressure sores are hazards that can be overcome by careful attention to nursing procedures. Later deaths are more common among patients transferred from the unit to hostels or hospitals than among patients transferred home. Specialist units for these patients improve the quality of their lives as well as their expectation of life. Electronic equipment can also play a large part in helping tetraplegics to play a part in community life.     

COVID-19 modeling and non-pharmaceutical interventions in an outpatient dialysis unit

This paper describes a data-driven simulation study that explores the relative impact of several low-cost and practical non-pharmaceutical interventions on the spread of COVID-19 in an outpatient hospital dialysis unit. The interventions considered include: (i) voluntary self-isolation of healthcare personnel (HCPs) with symptoms; (ii) a program of active syndromic surveillance and compulsory isolation of HCPs; (iii) the use of masks or respirators by patients and HCPs; (iv) improved social distancing among HCPs; (v) increased physical separation of dialysis stations; and (vi) patient isolation combined with preemptive isolation of exposed HCPs. Our simulations show that under conditions that existed prior to the COVID-19 outbreak, extremely high rates of COVID-19 infection can result in a dialysis unit. In simulations under worst-case modeling assumptions, a combination of relatively inexpensive interventions such as requiring surgical masks for everyone, encouraging social distancing between healthcare professionals (HCPs), slightly increasing the physical distance between dialysis stations, and—once the first symptomatic patient is detected—isolating that patient, replacing the HCP having had the most exposure to that patient, and relatively short-term use of N95 respirators by other HCPs can lead to a substantial reduction in both the attack rate and the likelihood of any spread beyond patient zero. For example, in a scenario with R₀ = 3.0, 60% presymptomatic viral shedding, and a dialysis patient being the infection source, the attack rate falls from 87.8% at baseline to 34.6% with this intervention bundle. Furthermore, the likelihood of having no additional infections increases from 6.2% at baseline to 32.4% with this intervention bundle.     

Factors contributing to discomfort or dissatisfaction as a result of wearing personal protective equipment

In a metal refining plant, 366 workers were interviewed to investigate factors contributing to the discomfort or dissatisfaction of wearing personal protective equipment (PPE). Up to 97.8% of these individuals used one or more types of PPE. The percentages of employees who reported their hard hats and cooling vests as comfortable were 17% and 19%, respectively. Twenty-five percent of workers felt their respirators and safety harnesses were comfortable. Safety glasses ranked at 50%, gloves 53%, and safety shoes 54% for comfort factor. The percentage of employees who tolerated their PPE (just acceptable) ranged from 27% to 52%. The most frequently cited factors contributing to discomfort or dissatisfaction of wearing PPE were related to the workers' beliefs that the PPE was not needed, created a new hazard, interfered with work, was too heavy, was hard to wear, prohibited breathing or communicating, irritated skin, put pressure on the body, and was of an undesirable type or model.