Peroxide Vapor Research Articles

Comparison of Aerosolized Hydrogen Peroxide Fogging with a Conventional Disinfection Product for a Dental Surgery

The study aimed to determine the efficacy of adding a 12% hydrogen peroxide dry hydrogen peroxide vapor fogger system as an additional layer of infection control in a dental surgery. A total number of agar plates from the five locations were used during the treatment of the 22 patients (n = 440). During the treatment of each patient, four agar plates (n = 4) were used per location [location 1: X-ray, location 2: the dental arm, location 3: left side desk, location 4: under the foot of the dental chair, location 5: ri ght side desk and (n = 20 for the five locations per patient)]. The control agar plates were incubated after the treatment of the patient was completed period. The test agar plate groups were sprayed with a 70% isopropanol surface disinfectant, or received exposure to an automated 12% hydrogen peroxide fog, or a 70% isopropanol surface disinfectant spray immediately followed by exposure to the automated 12% hydrogen peroxide. One-way ANOVA and Scheffé's method identified significant differences (p < 0.01). Between the control agar plates and the three disinfection methods used a significantly lower colony count was established for colonies recorded in the surgery assessed as a whole, the X-ray unit, and the ri ght side desk. The disinfection of dental surgery r equires sufficient time as it not only includes the working surfaces but also various inanimate objects. Surface disinfectant spray followed by hydrogen peroxide decontamination has potential for dental surgery, as the colony-forming units have been r educed further compared to spray alone and even just fog alone for all the various areas of the dental surgery that was assessed. The infection control protocols with hydrogen peroxide vapor would ensure the maximum efficacy of the disinfection protocols.

Sterilizálási lehetőségek a fogászatban. Rugalmas anyagok csírátlanításának korlátai egy eset kapcsán

In everyday dental practice, sterility is essential. Sterilizing different materials can require different methods. In the case of heat sensitive and elastic materials, most common techniques are not suitable because they need to be treated on lower temperature, not to lose their physical properties. For instance, if rubber dam is divested of elasticity, it is useless in restorative dentistry thereafter. Sterilizing rubber dam sheets is not a frequent process, but in certain cases it can be necessary. In such a situation, dentists have to choose between rare and hard-to-reach options. In our referral, we summarize the possibilities of sterilization, focusing on plasma sterilization and hydrogen-peroxide vapor sterilization. During the treatment of our presented case with a deep subgingival fracture line, affecting the crown and the root surface as well, we applied a rubber dam sheet, sterilized with hydrogen-peroxide vapor in order to use adhesive technique. Orv Hetil. 2020; 161(3): 110-115.

COVID Operation Theatre- Advisory and Position Statement of Indian Society of Anaesthesiologists (ISA National).

COVID Operation Theatre- Advisory and Position Statement of Indian Society of Anaesthesiologists (ISA National).

Decontamination Validation of a Class II Type A2 Biosafety Cabinet during Laboratory Fumigation.

The objective of this study was to evaluate whether a Class II type A2 biosafety cabinet in a laboratory could be decontaminated while the laboratory was being fumigated using vaporous hydrogen peroxide or peracetic acid dry fogging. To validate decontamination of all parts of the biosafety cabinet, biological indicators were placed at various locations within the biosafety cabinet, including between the pleats of supply and exhaust HEPA filters. To assess whether the operational status of the biosafety cabinet influenced the outcome of its decontamination, fumigation validations were undertaken with the cabinet running and not running. The amount of fumigant and the duration of fumigation remained constant whether the biosafety cabinet was running or not. Biosafety cabinet decontamination was successful only when the cabinet was running to facilitate the fumigant's circulation within the plenums and across the HEPA filters. This study shows both vaporous hydrogen peroxide and peracetic acid dry fogging can be used successfully to decontaminate Class II type A2 biosafety cabinets during laboratory fumigation, provided the biosafety cabinets are operational and running during the fumigation.

Porphyrin nanofiber/single-walled carbon nanotube nanocomposite-based sensors for monitoring hydrogen peroxide vapor

Detection of hydrogen peroxide (H2O2) is particularly important in the field of clinical diagnosis for exhaled breath analysis, because H2O2 is closely related to diseases such as cancer, traumatic brain injury, chronic obstructive pulmonary disease, and asthma. Considering this, development of sensors for sensitive and selective real-time monitoring of H2O2 vapor (HPV) is required. In this study, we report the design and fabrication of a high-performance HPV sensor based on nanocomposites of nanofibers of a porphyrin derivative (oxo-[5,10,15,20-tetra(4-pyridyl)porphyrinato]titanium(IV) (TiOTPyP)) and single-walled carbon nanotubes (SWCNTs) at room temperature. Two types of HPV sensor transducers were fabricated using pristine SWCNTs only and TiOTPyP nanofiber/SWCNT nanocomposite and the sensor responses were compared. The significant differences in reproducibility and selectivity of the two sensors reflected the significant impact of the added TiOTPyP nanofibers on the device performance. The response of the TiOTPyP nanofiber/SWCNT nanocomposite-based sensor to 1 ppm of HPV is 9 times higher than that of the pristine SWCNT-based sensor. In addition, this sensor shows fast response/recovery times in the detection of HPV in the concentration range of 0.1–10 ppm, while showing a weak response to NH3 gas and negligible response to CO, toluene, acetone, hexane, NO, and NO2 gases.

Low-concentration hydrogen peroxide decontamination for Bacillus spore contamination in buildings.

Remediation and recovery efforts after a release of Bacillus anthracis (anthrax) spores may be difficult and costly. In addition, response and recovery technologies may be focused on critical resources, leaving the small business or homeowner without remediation options. This study evaluates the efficacy of relatively low levels of hydrogen peroxide vapor (HPV) delivered from off-the-shelf equipment for the inactivation of Bacillus spores within an indoor environment. Decontamination evaluations were conducted in a house using both Bacillus atrophaeus var. globigii (Bg; as surrogates for B. anthracis ) inoculated on the carpet and galvanized metal as coupons and Geobacillus stearothermophilus (Gs) as biological indicators on steel. The total decontamination time ranged from 4 to 7 days. Using the longer exposure times, low concentrations of HPV (average levels below 20 parts per million) effectively inactivated Bg and Gs spores on the materials tested. The HPV was generated with commercial humidifiers and household-strength hydrogen peroxide solutions. The presence of home furnishings did not have a significant impact on HPV efficacy. This simple, inexpensive, and effective decontamination method could have significant utility for remediation following a B. anthracis spore release, such as following a terrorist attack.

Assessment of surface cleaning and disinfection in neonatal intensive care unit

BackgroundSurveillance for healthcare-associated infections (HAI) is a priority in the neonatal intensive care unit (NICU), given the critical immune status of patients. The aim of this study was to assess surface bacterial contamination before and after improving cleaning and disinfection practices. Materials and methodsThis was a cross-sectional study conducted in March 2018. Surface samples were taken from the same areas in three steps: after cleaning, after "improved" cleaning, and after terminal disinfection using hydrogen peroxide vapor (VHP). Sampling and culture was carried out according to standard ISO14698-1: 2004. Results interpretation was based on the thresholds defined by good hospital pharmacy practice. Statistical analysis was performed by SPSS 21.0 and a P-value < 0.05 was considered to be significant. ResultsIn total, 290 samples were taken from different zones: fixed equipment (69%), aseptic washbasins (12%), pneumatic system (9%), computer equipment (6%) and mobile equipment (4%). Prevalence of non-compliances after cleaning and disinfection was 75%, 10% after “improved” cleaning, and 0% after automated VHP (P < 0.0001). Median of CFU was 24[EI (0–625)] after standard cleaning, 2[EI (0–35)] after “improved” cleaning and 0 [EI (0–3)] after VHP (P < 0.0001). Isolated germs werecoagulase-negative Staphylococcus (31.2%), Acinetobacter baumannii (26%), Staphylococcus aureus (19.5%), Pseudomonas aeruginosa (9%), Klebsiella pneumoniae (9%), E. coli (4%) and Enterobacter sp (1.3%). ConclusionImproved cleaning and disinfection practices associated to VHP give microbiological satisfactory results. It is important to educate cleaning staff for effective surface cleaning and disinfection operations to control HAI.

2353. Easy Does It: Decreasing and Sustained Hospital-Onset (HO) CDI Lab-ID Event Incidence Through a Series of Interventions

Background Clostridioides difficile infection (CDI) Laboratory (Lab) identified (ID) events are reportable to CMS through the CDC’s NHSN. Prevention of transmission has been the main component of interventions; however, avoiding false-positive laboratory diagnoses can also lead to decreased incidence.MethodsA retrospective analysis of HO-CDI Lab-ID events was conducted to evaluate the results of a series of interventions at the University of Alabama Hospital, a 1150-bed tertiary care center in Birmingham, AL. The study period was from the first quarter of 2013 (1Q 2013) until 1Q of 2019. Interventions were implemented in sequential order were: (i) CDI prevention bundle education (3Q 2014); (ii) two-step laboratory testing algorithm (2Q 2015); (iii) selective enhanced environmental disinfection on oncology units (2Q 2016); (iv) diagnostic stewardship by reminding providers to reconsider testing if the patient received a laxative within 48 hours (4Q 2016).ResultsAt the beginning of the study period, the HO CDI Lab ID Event SIR was 0.96. The standard infection ratio (SIR) over the time period is shown in Figure 1. We observed a slight decrease in HO-CDI Lab ID event SIR after implementation of the CDI prevention bundle (0.96 vs. 0.77). A change in the diagnostic testing from PCR-based to a two-step algorithm (EIA testing for GDH and Toxin confirmed by PCR) resulted in a slight increase although not statistically significant (0.77 vs. 0.83). A downward trend was observed when selective enhanced terminal disinfection with hydrogen peroxide vapor was performed on all oncology patient rooms vacated by patients with CDI (0.83 vs. 0.72). The largest and sustained impact was observed after implementation of a computer-assisted diagnostic stewardship in which providers were reminded if the patient was administered any stool softener or laxative within 48 hours of the order for CDI testing (0.72 vs. 0.32). The institutions SIR value became significant in 2Q 2016 (P = 0.0014) and significance was maintained since that time. The difference between expected and observe HO-CDI Lab ID events is demonstrated in Figure 2.ConclusionThrough a series of interventions, we observed a decrease in HO-CDI event rates. Diagnostic stewardship with academic detailing resulted in the most impactful and sustained improvement. Disclosures All authors: No reported disclosures.

Technology of the sterilization by vaporized hydrogen peroxide

Technology of the sterilization by vaporized hydrogen peroxide

3D printed polymers are less stable than injection moulded counterparts when exposed to terminal sterilization processes using novel vaporized hydrogen peroxide and electron beam processes

There is an increasing trend for use of 3D printing processes in healthcare due in part to emergence of customised medical devices and associated low manufacturing cost. However, there is a dearth of knowledge on the efficacy of terminal sterilization processes on such 3D printing processes compared to conventional manufacturing methods, such as injection moulding. Therefore, the goal of this timely work was to compare the mechanical, thermal and chemical effects of vaporized hydrogen peroxide (VHP) and electron beam (E-beam) sterilization processes on the 3D printed and injection moulded high density polyethylene (HDPE) and Polyamide 6 samples. Characterization of materials post sterilization was performed by several analytical methods. Studies found that injection moulded samples exhibited higher tensile strength, higher degree of crystallinity, lower ductility, and higher thermal stability than 3D printed samples due to their tightly packed structures. After VHP and E-beam sterilization processes, oxidation and crosslinking occurred along with yellow colour change. Free hydroxyl radicals and intermolecular carbon bonding were detected by FTIR; the viscosity, storage modulus and loss modulus were increased due to crosslinking; the wettability of all the samples were increased due to the free radicals on the surface. However, the tensile properties of all samples measured were not affected by the VHP or E-beam processes, which was attributed to the low irradiation dosage of E-beam and good resistance to hydrolytic degradation from VHP. Overall, E-beam process resulted in more severe oxidation and crosslinking than VHP process, and sterilized 3D printed samples were less stable compared to injection moulded samples when exposed to terminal sterilization processes, which was evidenced with more new peaks related to oxidation and crosslinking detected by FTIR and the dramatic increase in the degree of crystallinity. These findings highlight the importance of considering choice of industrial terminal sterilization with view to future reduction of processing conditions for emerging additive manufacturing processes, such as in situ 3D printing that is often underappreciated.

Carbapenem-Resistant Enterobacteriaceae Outbreak in a Medical Ward in Spain: Epidemiology, Control Strategy, and Importance of Environmental Disinfection.

Introduction: Carbapenem-resistant Enterobacteriaceae (CRE) are a growing public health problem. We describe an outbreak by CRE and the measures to control it in a hospitalization unit in Spain. Methods: In June 2015, the system of prevention and control of CRE implemented in the hospital detected an increase in the incidence of patients with CRE in a mixed hospitalization facility (geriatrics, internal medicine, and pneumology), with the appearance of four related patients in 2 weeks, three of them being nosocomial cases. A multidisciplinary group was created and carried out: weekly screenings, general cleaning, four training sessions for personnel, two hand hygiene observation studies and environmental sampling. A higher incidence of new cases was detected in three adjoining rooms, in which environmental decontamination was performed with vaporized hydrogen peroxide. Results: In 5 months, a total of 18 cases were detected, 14 of them were nosocomial. Four different clones of Klebsiella pneumoniae OXA-48 were responsible for 83.3% of the cases. Adherence to hand hygiene increased from 36% to 85% after the training sessions. Seven percent of the environmental samples were positive for CRE in rooms with high incidence, moving to 0% after decontamination with hydrogen peroxide. Three patients died, one of them possibly associated with clinical infection due to CRE. Conclusions: Multidisciplinary information strategies, personnel training, and control of environmental reservoirs are effective to address outbreaks of CRE.

Effect of Sodium Ions on Catalytic Performance of TS-1 in Gas-Phase Epoxidation of Propylene with Hydrogen Peroxide Vapor

Na+ ions in TS-1 influence the results of liquid-phase oxidations of hydrocarbons seriously, and the avoiding of Na+ ion impurity in TS-1 synthesis is crucial for its catalytic application. In this paper, however, the solvent-free gas-phase epoxidation of propylene with H2O2 vapor (G-HPPO) was investigated over TS-1 zeolites with different Na+ ion content. Significant improvement in the performance of G-HPPO process was observed with NaOH solution hydrothermally modified TS-1 which had a Na/Ti ratio of 0.68. The performance of G-HPPO process was further enhanced when the Na/Ti ratio of hydrothermally modified TS-1 was increased to 1.0 via subsequent Na+ ion impregnation. The catalyst showed 16.9% propylene conversion, 97.5% PO selectivity and 79.3% H2O2 utility at a propylene to H2O2 ratio of around 5. On the other hand, when the Na+ ion content of the hydrothermally modified TS-1 was reduced via subsequent NH4+-exchange, the resulted catalyst exhibited a remarkably deteriorated G-HPPO process performance. By Combining the characterizations of UV–Raman, UV–vis and FT-IR with DFT calculation, it is concluded that in the NaOH solution hydrothermally modified TS-1 the Na+ ions served as counter cations of the silicon hydroxyls adjacent to “open” tetra-coordinated framework Ti sites. As a result, the local environment of the “open” Ti sites (with titanium hydroxyls) was adjusted and the Ti sites were properly activated. Whereas, in the case of excess Na+ ions were introduced into the TS-1 (for example Na/Ti ratio more than 1.0), the titanium hydroxyl of the “open” Ti sites would be occupied, to which the deteriorated G-HPPO process performance was ascribed.

Terminal sterilization of medical devices using vaporized hydrogen peroxide: a review of current methods and emerging opportunities.

Medical devices are an important and growing aspect of healthcare provision and are increasing in complexity to meet established and emerging patient needs. Terminal sterilization plays a vital role in the provision of safe medical devices. While terminal sterilization technologies for medical devices include multiple radiation options, ethylene oxide remains the predominant nonthermal gaseous option, sterilizing c.50% of all manufactured devices. Vaporized hydrogen peroxide (abbreviated VH2O2 by the International Organization for Standardization) is currently deployed for clinical sterilization applications, where its performance characteristics appear aligned to requirements, constituting a viable alternative low-temperature process for terminal processing of medical devices. However, VH2O2 has operational limitations that create technical challenges for industrial-scale adoption. This timely review provides a succinct overview of VH2O2 in gaseous sterilization and addresses its applicability for terminal sterilization of medical devices. It also describes underappreciated factors such as the occurrence of nonlinear microbial inactivation kinetic plots that may dictate a need to develop a new standard approach to validate VH2O2 for terminal sterilization of medical devices.

Hydrogen peroxide vapour is an effective replacement for Formaldehyde in a BSL4 Foot and mouth disease vaccine manufacturing facility.

An evaluation of the efficacy of 35% hydrogen peroxide vapour (HPV) against two strains of FMDV was conducted over a period of 6months. FMDV biological indicators were produced on-site using strains obtained from a commercial FMDV vaccine manufacturing process. FMDV biological indicators were distributed within a BSL4 laboratory and exposed to short duration hydrogen peroxide cycles. Variations in titre, support matrix (soiling), temperature and humidity were evaluated in a series of 16 exposures using over 200 individual FMDV indicators. Additional verification testing was performed in an operational material transfer lock to replicate real-world use. HPV was found to be efficacious in inactivating FMDV strains; the inoculum titre influenced the level of reduction achieved with the specified cycle. SIGNIFICANCE AND IMPACT OF THE STUDY: The classification of formaldehyde as a presumed human carcinogen has presented regulatory challenges for its continued use as a biocidal product. Institutions are actively seeking fumigants to replace formaldehyde and undertaking studies to validate biocidal efficacy, particularly in high-level biosafety facilities where the consequences of pathogen release can be extremely severe. This study builds on the already substantial scientific efficacy base of 35% hydrogen peroxide vapour and provides a comprehensive evaluation of the applicability of hydrogen peroxide vapour as a replacement for formaldehyde within a Foot & Mouth Disease (FMDV) vaccine manufacturing facility.

Effects of environmental disinfection on the isolation of vancomycin-resistant Enterococcus after a hospital-associated outbreak of Middle East respiratory syndrome

Environmental disinfection with sodium hypochlorite and hydrogen peroxide vapor was performed after a hospital-associated outbreak of Middle East respiratory syndrome. Although only 11% of total beds were disinfected, the isolation and vancomycin-resistance rates of Enterococcus spp significantly decreased for 2 months, whereas other multidrug-resistant organisms did not.

Gas-Phase Epoxidation of Propylene with Hydrogen Peroxide Vapor: Effect of Modification with NaOH on TS-1 Titanosilicate Catalyst in the Presence of Tetra-propylammonium Bromide

This study was related to a solvent-free gas-phase epoxidation of propylene with H2O2 vapor to synthesize propylene oxide (G-HPPO). Focus was given to the hydrothermal modification of TS-1 with NaO...

A summary on cutting edge advancements in sterilization and cleaning technologies in medical, food, and drug industries, and its applicability to spacecraft hardware

Issued primarily by COSPAR (the Committee On SPAce Research), international Planetary Protection Policies mandate that all spacecraft hardware in contact with extraterrestrial environments “of chemical evolution and/or origin of life interest and for which scientific opinion provides a significant chance of contamination which could compromise future investigations” (Kminek and Rummel, 2015) undergo biological burden control processes. These policies seek to limit the (forward) biological contamination of the target body by terrestrial microorganisms on the spacecraft, so that future missions to the target body will provide accurate and reliable scientific results. Also, these policies seek to prevent the (backward) biological contamination of the Earth by a sample returned from the target body. Bioburden reduction is an integral part of current space missions and its importance will magnify as bioburden requirements become more stringent in the future. Since life-detection and sample-return procedures require sterile handling in situ (to protect scientific results), subsystems and instruments which will be in contact with extraterrestrial matter must be sterilized to prevent a false positive. Since the first Viking mission, heat microbial reduction (HMR) has served as a well-understood common practice for reducing bioburden. More recently, NASA and ESA have approved a standard protocol for vapor hydrogen peroxide (VHP) microbial reduction to address some of the drawbacks of HMR by lowering operating costs and decreasing schedule impacts, as detailed in the certification processes conducted by NASA's Jet Propulsion Laboratory and Steris. Steris has also conducted many testing campaigns on behalf of JPL over the past 20 years. The main results of their campaigns are hence reported. However, even VHP has certain limitations that do not make it an all-encompassing microbial reduction/sterilization modality for spacecraft hardware. Therefore, this review also investigates the state-of-the-art sterilization and cleaning techniques used in other fields, such as in the medical, food, and drug industries, for application to flight hardware. Major techniques covered include cold atmospheric plasma, electron beam irradiation, and gamma irradiation. Some techniques have proven to be good candidates for adaptation for future NASA spacecraft missions. Techniques such as gamma irradiation (γ rad), can broaden the scope of NASA-approved protocols and expand the currently limited toolkit. Cleaning, the removal of bioburden, is also an important aspect of bioburden reduction; despite the best microbial reduction/sterilization technologies, dead microbes can interfere with and potentially invalidate the results of biosignature models of relevant celestial bodies. Therefore, cleaning techniques, such as carbon dioxide snow, can significantly contribute to the bioburden reduction process. With the development of standardized protocols for these additional microbial reduction/sterilization and cleaning modalities – in combination with the well-known techniques with NASA and ESA approved protocols – we anticipate that future space missions may be able to achieve a higher biological standard.

The Diffusion of Hydrogen Peroxide Into the Liquid Product During Filling Operations Inside Vaporous Hydrogen Peroxide–Sterilized Isolators Can Be Predicted by a Mechanistic Model

Isolators are commonly used in filling operations of pharmaceutical products. To ensure an aseptic inner environment, isolators are regularly sterilized with vaporized hydrogen peroxide. However, despite extensive purging with air, some residual H2O2 remains within the isolator atmosphere and may thus end up in the liquid pharmaceutical drug product, which subsequently may cause oxidation and impact the product’s safety and efficacy. We aimed to evaluate the extent of this phenomenon and to model it. For that purpose, we studied the diffusion of H2O2 into water contained in small recipients exposed to the atmosphere of a H2O2-sterilized small-scale test isolator. Based on the results, a mechanistic model was proposed to estimate the quantity of H2O2 in the product, taking into account the time, filling volume, H2O2 concentration, and a configuration factor. Afterward, this model was challenged by filling water at a manufacturing scale, and we observed that the diffusion model could predict the trend of increasing H2O2 concentration. However, a consistent difference in H2O2 concentration between the model and the experimental results was observed, suggesting the contribution of another parameter. Our results can be used to predict more accurately H2O2 concentration in a pharmaceutical product at the manufacturing level.

Investigation of Sensor Made of ZnO:La for Detection of Hydrogen Peroxide Vapours by Impedance Spectroscopy Method

In this work, the impedance spectroscopy is presented as a promising method for the investigation of the sensitivity of gas semiconductor sensors. The sensor made of the ZnO nanosize film doped with the 1 at.% La was manufactured and its sensitivity investigated to the hydrogen peroxide vapors. The advantages of impedance spectroscopy compared with the studies of current-voltage characteristics are shown.

Disinfection efficiency of positive pressure respiratory protective hood using fumigation sterilization cabinet

Concerns have been raised about both the disinfection and the reusability of respiratory protective equipment following a disinfection process. Currently, there is little data available on the effects of disinfection and decontamination on positive pressure respiratory protective hoods (PPRPH). In this study, we evaluated the effect of vaporized hydrogen peroxide (VHP) on the disinfection of PPRPH to determine applicability of this method for disinfection of protective equipment, especially protective equipment with an electric supply system.A hydrogen peroxide-based fumigation sterilization cabinet was developed particularly for disinfection of protective equipment, and the disinfection experiments were conducted using four PPRPHs hung in the fumigation chamber. The pathogenic microorganism Geobacillus stearothermophilus ATCC 7953 was used as a biological indicator in this study and the relationship between air flow (the amount of VHP) and disinfection was investigated. Both function and the material physical properties of the PPRPH were assessed following the disinfection procedure. No surviving Geobacillus stearothermophilus ATCC 7953, both inside and outside of these disinfected PPRPHs, could be observed after a 60 min treatment with an air flow of 10.5–12.3 m3/h. Both function and material physical properties of these PPRPHs met the working requirements after disinfection.This study indicates that air flow in the fumigation chamber directly influences the concentration of VHP. The protective equipment fumigation sterilization cabinet developed in this paper achieves the complete sterilization of the PPRPHs when the air flow is at 10.5–12.3 m3/h, and provides a potential solution for the disinfection of various kind of protective equipment.