Hypochlorite Bleach Research Articles

Study on Alkali-Oxygen Pulping of Bagasse Wet-Stored with Hypochlorite Bleaching Waste Water

In this paper, the bagasse wet-stored with hypochlorite (H) bleaching waste-water which was the original waste liquid from H bleaching process of bagasse, was cooked with alkali-oxygen and its pulping effect was studied. The results showed that the proper treatment time of wet storage with H bleaching waste-water was 12 days, the pulping properties were as follows: screened pulp yield 62.9%, kappa number 15.4, viscosity 802 mL/g, and brightness 58.8 %ISO. The strength properties of pulp were as follows: tensile index 65.6 N•m/g, tear index 5.86 mN•m2/g, burst index 3.83 kPa•m2/g and folding endurance 302 times. In addition, the pulping properties of bagasse wet-stored with H bleaching waste-water were similar to those of bagasse wet-stored with fresh water. Therefore, it can be concluded that the H bleaching waste-water could be used as spraying water for wet storage of bagasse. It was a new idea for saving fresh water in the pulping and papermaking industry.

An Evaluation of Historical Bleaching with Chlorine Dioxide Gas, Sodium Hypochlorite, and Chloramine-T at the Fogg Art Museum

AbstractIn the mid-twentieth century, drawings by Jean-Auguste-Dominique Ingres at the Fogg Art Museum were treated with chemical bleaches such as chlorine dioxide gas, sodium hypochlorite, and chloramine-T. Fifty years later, the darkened condition of the drawings was attributed to bleaching with chlorine dioxide gas. This paper discusses the three methods developed by Rutherford John Gettens to generate chlorine dioxide gas from sodium chlorite, formaldehyde and formic acid, examines the use of these bleaching methods to treat Ingres drawings at the Fogg, and discusses the sodium hypochlorite and chloramine-T bleaching methods also in use at the time. The treatments of two Ingres drawings are compared and evaluated in light of later bleaching studies and the current condition of each drawing. All of these historical bleaching methods, as practiced on the works studied, contributed to the darkening and colour/brightness reversion of drawings.

Disinfection of Treated Wastewater and its Reuse in the Irrigation of Golf Grass: The Case of Plant M’zar Agadir-Morocco

The treated wastewater of Agadir M’zar plant has a good physico-chemical quality and it contains important nutrients (NPK: nitrogen, phosphorus, potassium). However, the reuse of this water, without disinfecting it, for irrigating the golf grass in the Agadir region, revealed the presence of a bacterial load that can hinder the quality and suitability of spaces for a population that is very demanding. Among the various methods of water disinfection, chlorination with bleach is the least expensive and the most systematically simple. Its effectiveness depends only on the pH of the waters to be disinfected. This study reports the results of disinfection of M’zar plant wastewater with a solution of sodium hypochlorite (bleach), and their reuse for irrigating the golf grass. For this purpose, we carried out a monitoring protocol for germination and growth parameters (number of tillers and leaf length) in order to study and compare the effect of disinfected treated wastewater (DTWW) and groundwater (GW) on the plant turf. The obtained result showed that the disinfection with bleach increased the salinity of the treated wastewater and can affect the permeability of soils and crops.

Esophageal perforation and mediastinitis after suicidal ingestion of 4.5% sodium hydrochlorite bleach

A 16-year-old woman deliberately drank 4.5% sodium hypochlorite bleach. She was transferred to the emergency department after gastric lavage was performed at a local clinic. She experienced chest pain and fever after several vomiting episodes and esophagoscopy. Chest computerized tomography (CT) revealed air bubbles and abnormal soft tissue density at the right lateral aspect of the mid esophagus, a small amount of complicated pleural effusion, and pneumothorax. Barium esophagography revealed abnormal leakage of contrast media at the right wall of the mid esophagus, which indicated acute mediastinitis. The patient received intensive care and underwent delayed esophageal repair and colonic transplant. She was discharged 12 weeks after admission.Sodium hypochlorite is found in household bleaching agents used to disinfect dishes and bleach laundry. Poisoning due to ingestion of sodium hypochlorite bleach usually follows a benign clinical course. Few studies report severe complications such as esophageal stenosis or perforation.

Decontamination of blood soaked electronic devices using ultrasonic technology

With advancements in technology allowing for the miniaturization of consumer electronics, criminal investigations of all types frequently involve the forensic examination of electronic devices, such as cellular telephones, smartphones, and portable flash memory; in some extreme, violent cases, these devices are found covered in blood. Due to the complexity of such devices, standard operating procedures for the complete removal of blood had not previously been established by the Royal Canadian Mounted Police prior to this study. The electronics industry has adopted the use of the ultrasonic cleaner for sanitizing printed circuit boards (PCBs) by removing residues and contaminants. High frequency sound waves created by the machine penetrate and remove dirt and residues; however, early research during the 1950s recorded these sound waves breaking the internal bonds of integrated circuit chips. Experimentation with modern ultrasonic technology was used to determine if internal components were damaged, as well as if ultrasonic cleaning was the most suitable method for the removal of dried and liquid blood from a PCB. Several disinfectant solutions were compared against the 0.5% Triton(®) X-100 detergent solution in the ultrasonic cleaner, including: 10% sodium hypochlorite bleach, 85% isopropyl alcohol, and Conflikt(®) disinfectant spray. The results not only demonstrated that the ultrasonic cleaner did not damage the vital memory chip on the PCB, but also, with the assistance of Conflikt(®), was able to remove all traces of blood as indicated by Hemastix(®) reagent strips. Of five methods experimented with, two cycles of ultrasonic cleaning followed by sanitization with Conflikt(®) proved to be the only procedure capable of removing all traces of blood, as confirmed with both Hemastix(®) reagent strips and the hemochromogen test.

Before you reach for the bleach...

Sodium hypochlorite (bleach) is advocated as an irrigant for use in endodontic therapy for its bacteriocidal and tissue dissolving properties. Extrusion of hypochlorite into the surrounding soft and hard tissues, however, can lead to severe complications, as illustrated in our four case reports. This article considers the risk benefit ratio of the different materials available and advises dental practitioners to ensure patients are aware of the potential risks of the materials used when seeking informed consent. It also aims to provide some guidance on prevention, identification and management of incidents.

Effect of sterilization techniques on the physicochemical properties of polysulfone hollow fibers

AbstractSterilized hollow‐fiber membranes are used in hemodialysis, ultrafiltration, bioprocessing, and tissue engineering applications that require a stable and biocompatible surface. In this study, we demonstrated significant changes in the fiber physicochemical properties with different methods of sterilization. Commercial polysulfone (PS) hollow fibers containing poly(vinyl pyrrolidone) were subjected to standard ethylene oxide (ETO), sodium hypochlorite (bleach), and electron‐beam (e‐beam) sterilization techniques followed by analysis of the surface hydrophilicity, morphology, and water‐retention ability. E‐beam sterilization rendered more hydrophilic fibers with water contact angles near 47° compared to the ETO‐ and bleach‐treated fibers, which were each near 56°. Atomic force microscopy revealed lumen root mean square (rms) roughness values near 19 nm for all three sterilization methods; however, e‐beam‐sterilized and bleach‐treated fibers had significantly higher (∼ 106 nm) rms values for the outer wall compared to the ETO‐sterilized fibers (∼ 39 nm). The increased hydrophilicity and surface area of the e‐beam‐sterilized fiber were reflected by a greater water evaporation rate than that of the ETO‐treated fiber. These results demonstrate that common sterilization methods may significantly and distinctly alter the polymer membrane physicochemical properties, which may, in turn, impact the performance and, in particular, surface fouling. For tissue engineering and bioprocessing applications, these changes may be leveraged to promote cell adhesion and spreading. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

Stress-Induced Hsp70 Gene Expression and Inactivation of Cryptosporidium parvum Oocysts by Chlorine-Based Oxidants

Our research on the mechanisms of action of chlorine-based oxidants on Cryptosporidium parvum oocysts in water revealed a dual-phase effect: (i) response to oxidative stress, which was demonstrated by induced expression of the Hsp70 heat shock gene, and (ii) oocyst inactivation as a result of long-term exposure to oxidants. The relative biocidal effects of sodium hypochlorite (bleach) and electrolytically generated mixed oxidant solution (MOS) on C. parvum oocysts were compared at identical free chlorine concentrations. Oocyst inactivation was determined by quantitative reverse transcription-PCR (qRT-PCR) amplification of the heat-induced Hsp70 mRNA and compared with tissue culture infectivity. According to both assays, within the range between 25 and 250 mg/liter free chlorine and with 4 h contact time, MOS exhibits a higher efficacy in oocyst inactivation than hypochlorite. Other RNA-based viability assays, aimed at monitoring the levels of beta-tubulin mRNA and 18S rRNA, showed relatively slow decay rates of these molecules following disinfection by chlorine-based oxidants, rendering these molecular diagnostic viability markers inappropriate for disinfection efficacy assessment.

Non-wood fibre production of microcrystalline cellulose from Sorghum caudatum: Characterisation and tableting properties

The microcrystalline cellulose is an important ingredient in pharmaceutical, food, cosmetic and other industries. In this study, the microcrystalline cellulose, obtained from the stalk of Sorghum caudatum was evaluated for its physical and tableting characteristics with a view to assessing its usefulness in pharmaceutical tableting. The microcrystalline cellulose, obtained from the stalk of Sorghum caudatum, obtained by sodium hydroxide delignification followed by sodium hypochlorite bleaching and acid hydrolysis was examined for its physicochemical and tableting properties in comparison with those of the well-known commercial microcrystalline cellulose grade, Avicel PH 101. The extraction yield of this microcrystalline cellulose, obtained from the stalk of Sorghum caudatum was approximately 19%. The cellulose material was composed of irregularly shaped fibrous cellulose particles and had a moisture content of 6.2% and total ash of 0.28%. The true density was 1.46. The flow indices showed that the microcrystalline cellulose, obtained from the stalk of Sorghum caudatum flowed poorly. The hydration, swelling and moisture sorption capacities were 3.9, 85 and 24%, respectively. Tablets resulting from these cellulose materials were found to be without surface defects, sufficiently hard and having disintegration time within 15 min. The study revealed that the microcrystalline cellulose, obtained from the stalk of Sorghum caudatum compares favourably with Avicel PH 101 and conformed to official requirement specified in the British Pharmacopoeia 1993 for microcrystalline cellulose.

Mass Casualties from Acute Inhalation of Chlorine Gas

Chlorine gas is a potent pulmonary irritant that affects the mucous membranes and induces severe disturbances of pulmonary gas exchange within minutes of inhalation. The present study evaluated an extraordinary type of mass inhalational exposure. Clinical reports of 25 soldiers who were admitted to the emergency department of Maresal Cakmak Military Hospital, Erzurum were retrospectively evaluated. All patients were exposed to chlorine gas as a result of mixing sodium hypochlorite with hydrochloric acid during cleaning activities. All patients were male and the mean age of patients was 22.04+/-2.98 years. The main symptoms were coughing and dyspnea in 18 patients (72%). Forced expiratory volume in 1 second (FEV1) and FEV1/forced volume capacity (FVC) ratio were found to be normal in all patients but FVC and peak expiratory flow (PEF) were below the normal range (80%) in 9 patients (36%). All patients received warmed humidified oxygen combined with nebulized salbutamol. Inhaled budesonide and nebulized sodium bicarbonate were ordered additionally for 19 patients (76%). Thirteen patients (52%) were discharged from the emergency department and 12 patients (48%) were hospitalized. No mortality was observed. Chlorine gas is a potent pulmonary irritant that causes acute damage in both the upper and lower respiratory tract. We suggest that inhaled steroids combined with nebulized sodium bicarbonate could be a safe and effective alternative for the treatment of symptomatic patients. Education of the public about the dangers of mixing of hypochlorite bleach with acidic cleaning agents is also very important.

Management of a multidrug-resistant Acinetobacter baumannii outbreak in an intensive care unit using novel environmental disinfection: A 38-month report

Between June 1, 2004, and March 14, 2005, 16 patients in the surgical/medical intensive care unit (ICU) were infected and another 2 were colonized with multidrug-resistant (MDR) Acinetobacter baumannii. We describe the systematic investigation initiated to discover an environmental reservoir and a novel measure taken to terminate the outbreak. Cultures were taken from moist areas in the ICU, including sink traps, sink and counter surfaces, drains, and faucets. Strains were characterized using restriction endonuclease analysis. A weekly full drainpipe chase cleansing protocol with sodium hypochlorite (bleach) solution for all 24 ICU and waiting room area sinks connected by common plumbing was initiated in March 2005. Eleven of 16 infected patients (69%) had a clonal MDR strain, 1 patient (6%) was infected with an unrelated strain, and in 4 patients (25%) strains were not available for typing. The reservoir for the A baumannii clone was detected in a sink trap within one of the ICU patient rooms that likely represented contamination of the entire horizontal drainage system. The bleaching protocol initiated in March 2005 successfully decontaminated the reservoir and eliminated the MDR A baumannii infections. A systematic search for an environmental reservoir followed by decontamination significantly reduced (P < .01) the incidence of MDR A baumannii infection.

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 mum, and the sizes of the majority of the droplets were the range from 0.74 to 3.5 mum. 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 (> or =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/cm(2) (3 h of contact time with a UV intensity of 0.4 mW/cm(2)), while with higher doses of UV irradiation (> or =7.20 J/cm(2); UV intensity, 0.4 mW/cm(2); contact times, > or =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.

MRSA Decolonization and Brown Bath Water

To the Editors: Methicillin-resistant Staphylococcus aureus (MRSA) is a common cause of skin infections. Management of recurrent skin lesions caused by MRSA is challenging and optimal prevention strategies have not been established.1 Decreasing bacterial colonization of the skin has been a widely used strategy, although decolonization regimens vary by physician.2 Chlorhexidine gluconate, hexachlorophene, and household bleach (sodium hypochlorite) have been recommended for use during bathing or showering to help decolonize MRSA on skin surfaces. We recently participated in the medical care of a child with recurrent skin infections in which the family mistakenly used 2 of the above agents (sodium hypochlorite and a chlorhexidine product) simultaneously during the child's bath. Use of these 2 agents together created a color change in the bath water. A 2-year-old girl was seen with a history of recurrent purulent lesions on her lower extremities and perineal area. No cultures of these lesions had previously been obtained. In the clinic, the child was asymptomatic. Cultures of the child's nose and groin were obtained. A prescription for intranasal mupirocin ointment for topical use was given to the mother, as were instructions for the use of household bleach, 1 teaspoon per gallon of water, in the child's bath. When culture results returned showing both methicillin-susceptible S. aureus and MRSA, the mother was contacted. The mother reported that the child's bath water turned brown soon after she began using the sodium hypochlorite (bleach). Upon further questioning, the mom indicated that she was also using another product during the child's bath. This product was determined to contain chlorhexidine gluconate. It was recommended that the mother discontinue the chlorhexidine-containing product and use bleach only. Once the mother stopped using both agents, the bath water no longer turned brown. Reportedly, the brown bath water had not caused any staining or discoloration of the child's skin, bath fixtures, or washcloths. Although the authors are unaware of any pediatric literature involving the simultaneous use of chlorhexidine products and sodium hypochlorite in the management of children with recurrent MRSA infections, there are articles in the dental literature about brown discoloration when “bleaching” teeth with these agents.3,4 The combination of chlorhexidine and sodium hypochlorite can form a precipitate (brown flocculate).3,4 The authors also found reference to brown discoloration when examining the 2008 Data Sheet (package insert) from HiBi (chlorhexidine gluconate 2% wt/vol isopropyl alcohol 70% vol/vol, Mölnlycke Health Care, Manchester, UK). The package insert warns “Do not use chlorhexidine containing products in conjunction with or in area where cleaning agents containing bleach have been used as permanent brown stains can develop on fillings, fixtures, and clothing.” Hibiclens, a frequently used US product containing chlorhexidine gluconate, (Mölnlycke Health Care, Norcross, GA), has a warning in the package insert about using chlorhexidine and chlorine bleach together in the laundry (possible staining). The Hibiclens package insert recommends switching to a peroxide-type bleach to eliminate the reaction and “minimize possible staining.” Chlorhexidine gluconate, when used as a hand cleanser, bonds to a protein on the skin and has residual activity over a relatively long (hours) period of time. Chlorhexidine also bonds to fabrics, especially cotton (Hibiclens package insert, Mölnlycke Health Care, Norcross, GA). Physicians and other healthcare providers need to be aware of a chemical interaction which may occur between chlorhexidine gluconate and sodium hypochlorite and the need to advise patients and families to avoid the simultaneous use of these 2 agents for personal hygiene and laundry. Dennis L. Murray, MD, FAAP, FIDSA Department of Pediatrics Medical College of Georgia Augusta, GA Weng Man Lam, PharmD University of Georgia College of Pharmacy Medical College of Georgia Department of Pharmacy Augusta, GA

Global transcriptome analysis of the Mycobacterium bovis BCG response to sodium hypochlorite

Tuberculosis is a common and often deadly infectious disease caused by mycobacteria, mainly Mycobacterium tuberculosis and infrequently by other subspecies of the M. tuberculosis complex, such as M. bovis. Sodium hypochlorite (bleach) is routinely used in hospitals and health care facilities for surface sterilization; however, the modes of action of bleach on M. bovis BCG and how this organism develops resistance to sodium hypochlorite have not been elucidated. In this study, we performed a global toxicogenomic analysis of the M. bovis response to 2.5 mM sodium hypochlorite after 10 and 20 min. M. bovis BCG growth was monitored by measuring the quantity of ATP in picomoles produced over a short exposure time (10-60 min) to sodium hypochlorite. This study revealed significant regulation of oxidative stress response genes of M. bovis BCG, such as oxidoreductase, peroxidase, heat shock proteins and lipid transport, and metabolism genes. We interpreted this response as a potentially more lethal interplay between fatty acid metabolism, sulfur metabolism, and oxidative stress. Our results also suggest that sodium hypochlorite repressed transcription of genes involved in cell wall synthesis of M. bovis. This study shows that the treatment of M. bovis BCG with bleach inhibits the biosynthesis of outer cell wall mycolic acids and also induces oxidative damage.

Domestic use of hypochlorite bleach, atopic sensitization, and respiratory symptoms in adults

Professional use of hypochlorite (bleach) has been associated with respiratory symptoms. Bleach is capable of inactivating allergens, and there are indications that its domestic use may reduce the risk of allergies in children. To study the associations between household use of bleach and atopic sensitization, allergic diseases, and respiratory health status in adults. We identified 3626 participants of the European Community Respiratory Health Survey II in 10 countries who did the cleaning in their homes and for whom data on specific serum IgE to 4 environmental allergens were available. Frequency of bleach use and information on respiratory symptoms were obtained in face-to-face interviews. House dust mite and cat allergens in mattress dust were measured in a subsample. Associations between the frequency of bleach use and health outcomes were evaluated by using multivariable mixed logistic regression analyses. The use of bleach was associated with less atopic sensitization (odds ratio [OR], 0.75; 95% CI, 0.63-0.89). This association was apparent for specific IgE to both indoor (cat) and outdoor (grass) allergens, and was consistent in various subgroups, including those without any history of respiratory problems (OR, 0.85). Dose-response relationships (P < .05) were apparent for the frequency of bleach use and sensitization rates. Lower respiratory tract symptoms, but not allergic symptoms, were more prevalent among those using bleach 4 or more days per week (OR, 1.24-1.49). The use of bleach was not associated with indoor allergen concentrations. People who clean their homes with hypochlorite bleach are less likely to be atopic but more likely to have respiratory symptoms.

Feline panleukopenia. ABCD guidelines on prevention and management.

OverviewFeline panleukopenia virus (FPV) infects all felids as well as raccoons, mink and foxes. This pathogen may survive in the environment for several months and is highly resistant to some disinfectants.InfectionTransmission occurs via the faecal–oral route. Indirect contact is the most common route of infection, and FPV may be carried by fomites (shoes, clothing), which means indoor cats are also at risk. Intrauterine virus transmission and infection of neonates can occur.Disease signsCats of all ages may be affected by FPV, but kittens are most susceptible. Mortality rates are high – over 90% in kittens. Signs of disease include diarrhoea, lymphopenia and neutropenia, followed by thrombocytopenia and anaemia, immunosuppression (transient in adult cats), cerebellar ataxia (in kittens only) and abortion.DiagnosisFeline panleukopenia virus antigen is detected in faeces using commercially available test kits. Specialised laboratories carry out PCR testing on whole blood or faeces. Serological tests are not recommended, as they do not distinguish between infection and vaccination.Disease managementSupportive therapy and good nursing significantly decrease mortality rates. In cases of enteritis, parenteral administration of a broad-spectrum antibiotic is recommended. Disinfectants containing sodium hypochlorite (bleach), peracetic acid, formaldehyde or sodium hydroxide are effective.Vaccination recommendationsAll cats – including indoor cats – should be vaccinated. Two injections, at 8–9 weeks of age and 3–4 weeks later, are recommended, and a first booster 1 year later. A third vaccination at 16–20 weeks of age is recommended for kittens from environments with a high infection pressure (cat shelters) or from queens with high vaccine-induced antibody levels (breeding catteries). Subsequent booster vaccinations should be administered at intervals of 3 years or more. Modified-live virus vaccines should not be used in pregnant queens or in kittens less than 4 weeks of age.

Treatment of Staphylococcus aureus Colonization in Atopic Dermatitis Decreases Disease Severity

The goals were to determine the prevalence of community-acquired methicillin-resistant Staphylococcus aureus colonization in patients with atopic dermatitis and to determine whether suppression of S aureus growth with sodium hypochlorite (bleach) baths and intranasal mupirocin treatment improves eczema severity. A randomized, investigator-blinded, placebo-controlled study was conducted with 31 patients, 6 months to 17 years of age, with moderate to severe atopic dermatitis and clinical signs of secondary bacterial infections. All patients received orally administered cephalexin for 14 days and were assigned randomly to receive intranasal mupirocin ointment treatment and sodium hypochlorite (bleach) baths (treatment arm) or intranasal petrolatum ointment treatment and plain water baths (placebo arm) for 3 months. The primary outcome measure was the Eczema Area and Severity Index score. The prevalence of community-acquired methicillin-resistant S aureus in our study (7.4% of our S aureus-positive skin cultures and 4% of our S aureus-positive nasal cultures) was much lower than that in the general population with cultures at Children's Memorial Hospital (75%-85%). Patients in the group that received both the dilute bleach baths and intranasal mupirocin treatment showed significantly greater mean reductions from baseline in Eczema Area and Severity Index scores, compared with the placebo group, at the 1-month and 3-month visits. The mean Eczema Area and Severity Index scores for the head and neck did not decrease for patients in the treatment group, whereas scores for other body sites (submerged in the dilute bleach baths) decreased at 1 and 3 months, in comparison with placebo-treated patients. Chronic use of dilute bleach baths with intermittent intranasal application of mupirocin ointment decreased the clinical severity of atopic dermatitis in patients with clinical signs of secondary bacterial infections. Patients with atopic dermatitis do not seem to have increased susceptibility to infection or colonization with resistant strains of S aureus.

Efficacy of select disinfectants at inactivating Ranavirus

Ranavirus can cause disease in reptiles and amphibians. Because survival time outside of a host remains uncertain, equipment must be disinfected to prevent transmission of ranaviruses. However, disinfectant efficacy against amphibian ranaviruses has not been investigated for chlorhexidine (Nolvasan), sodium hypochlorite (bleach), or potassium compounds. Our goal was to determine the efficacy of Nolvasan (0.25, 0.75 and 2.0%), bleach (0.2, 1.0, 3.0 and 5.0%), and Virkon S (1.0%) at inactivating Ranavirus at 1 and 5 min contact durations. Potassium permanganate (KMnO4) (2.0 and 5.0 ppm) was also tested with a 60 min contact time. Nolvasan at 0.75 and 2.0% and bleach at 3.0 and 5.0% concentration were effective for both contact durations. Virkon S was effective for both durations, but KMnO4 was not effective at either concentration. Concentrations of Nolvasan, bleach and Virkon S that are at least 0.75, 3.0 and 1.0%, respectively, are effective at inactivating Ranavirus after 1 min exposure time.

Substrate Durability Guidelines Used in Silicone Structural Attachment

Abstract This paper sets forth a procedure for evaluating substrates for durability for use in conjunction with structural silicone glazing (SSG). Lap shear and peel adhesion specimens are evaluated after exposures to various conditions using a modified ASTM C794-06, “Standard Test Method for Adhesion-In-Peel of Elastomeric Joint Sealants,” and ASTM C961-06, “Standard Test Method for Lap Shear Strength of Sealants.” Conditions of exposure include water, sodium hypochlorite (bleach), acetic acid (vinegar), salt fog, UV florescent accelerated weathering device (UVFl), ultraviolet light (UV) exposure, and heat. Evaluation of substrates and the interfaces are completed after tensile testing and visual surface analysis. The silicone structural glazing adhesive used in this evaluation is a high modulus high strength material intended to place the maximum load at the interface. Substrates evaluated include steel, anodized aluminum, galvanized steel, extruded rigid polyvinyl chloride (PVC), glass reinforced thermoplastic resin (fiberglass), and polyvinylidene fluoride (PVDF) painted aluminum. These evaluated substrates are tested to this procedure to show differences in performance and suggest a minimum time frame required for testing. The results and guidelines set forth in this paper provide the foundation for a practice and or a substrate specification for use in conjunction with structural silicone attachment methods.

A Comparison Among Performance Characteristics of Various Denim Fading Processes

The aim of this study was to examine the effect of fading methods such as sand-blasting, laser and washing on performance properties of denim products. In this study, on one type of denim fabric, fading methods by laser and sand-blasting were applied in different intensities and pressures, and then fabrics were washed with the aid of different types of washing processes. Also, another denim fabric group was only washed by applying different types of washing processes. At the end of the study, loss of weight, color abrasion and loss of tensile strength of denim fabrics were measured. As a result, fading methods decreased tensile strength and weight values and the decrease rates changed in line with the intensity and the pressure of fading methods. Furthermore, color abrasion values of the fabrics changed due to the intensity and the pressure of fading methods. Back-staining values decreased after laccase enzyme and hypochlorite bleaching, but after other washings, back-staining values increased due to washing type.