Bleach

M. Hahn , J.A. Weber , in Encyclopedia of Toxicology (Third Edition), 2014

Abstract

Sodium hypochlorite (bleach, CAS 7681-52-nine) is an aqueous solution produced by the mixture of chloramine gas and h2o. It is used as a disinfectant in various settings. Toxicity is dependent on concentration, route, and duration of exposure. Availability in households attributes to frequent exposures. Toxic effects vary from mild irritation to significant tissue harm. Most unintentional exposures event as minor irritation. Intentional ingestions tin can crusade pregnant burns or strictures of the gastrointestinal tract. Dermal and ocular exposures can crusade irritation and corrosive injuries. Sodium hypochlorite combined with an acid or ammonia forms chlorine and chloramine gases, which cause upper respiratory irritation to chemical pneumonitis.

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Bleach

Julie Weber , in Encyclopedia of Toxicology (Second Edition), 2005

Mechanism of Toxicity

The toxicity of hypochlorite arises from its corrosive activity on skin and mucous membranes. Corrosive burns may occur immediately upon exposure to concentrated bleach products. Almost of this corrosiveness stems from the oxidizing potency of the hypochlorite itself, a capacity that is measured in terms of 'available chlorine'. The alkalinity of some preparations may contribute substantially to the tissue injury and mucosal erosion. Sodium hypochlorite when combined with an acid or ammonia may produce chlorine or chloramine gas, respectively. An inhalation exposure to these gases may event in irritation to mucous membranes and the respiratory tract, which may manifest itself as a chemically induced pneumonitis.

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Topical Therapeutics

Connor R. Buechler , Steven D. Daveluy , in A Comprehensive Guide to Hidradenitis Suppurativa, 2022

Bleach Baths

Bleach (sodium hypochlorite) is best known as an antimicrobial household cleaner, for which it relies on the cosmos of superoxide radicals to destroy bacteria, spores, viruses, and fungi. Previous studies have constitute that dilute (0.005%) bleach baths create a bacteriostatic result in as little every bit 5 minutes, 56 and the superoxide radicals exhibit a concentration-dependent ability to penetrate and dissipate biofilms created by leaner. 88 Withal, information technology is of import to note that contempo testify suggests dilute bleach baths have no direct antimicrobial ability, 89 thus whatsoever benefits may not exist due to the previously presumed antiseptic properties. Bleach besides exhibits antiinflammatory properties 90 that have made it an important part of dermatological therapy in recent years, especially as treatment for acute flares of atopic dermatitis. 91 This antiinflammatory consequence is postulated to exist due to the modulation of nuclear cistron kappa B transcription factor, signaling and resulting in decrease of inflammatory cytokine levels. 92 While in that location have, every bit withal, been no studies of the efficacy of bleach baths for HS, their use is recommended by several treatment guidelines developed by expert committees. 78,93,94

Bleach baths are typically kept to 0.005% bleach (0.5 cup of household bleach per standard twoscore gallon [150 L] bathtub) for optimal benefit while avoiding caustic impairment to the skin. More concentrated preparations accept been known to cause urticaria and irritant contact dermatitis. There are no clinical studies demonstrating the effect of varying frequency of bleach baths for treatment of HS, but 2 to 3 times weekly at 0.005% concentration is thought to produce benefit. 93 Patients should exist cautioned regarding the caustic effects of full-bodied bleach on the pare, as well as the potential for bleaching of hair and fabrics. Although pigmentation changes may occur with more concentrated preparations, skin pigmentation should not occur at the recommended 0.005% concentration.

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Biocompatibility and Tissue Reaction to Biomaterials

In Craig'southward Restorative Dental Materials (Thirteenth Edition), 2012

Bleaching Agents

Bleaching agents have been used on nonvital and vital teeth for many years, but their employ on vital teeth has increased astronomically in contempo years. These agents commonly contain some class of peroxide (generally carbamide or hydrogen peroxide) in a gel that can be applied to the teeth either by a dentist or at home by a patient. The agents may be in contact with teeth for several minutes to several hours depending on the conception of the material. Domicile bleaching agents may be applied for weeks to even months in some cases. in vitro studies have shown that peroxides can apace (within minutes) traverse the dentin in sufficient concentrations to be cytotoxic. The cytotoxicity depends to a large extent on the concentration of the peroxide in the bleaching agent. Other studies take even shown that peroxides can speedily penetrate intact enamel and accomplish the pulp in a few minutes. In vivo studies have demonstrated adverse pulpal effects from bleaching, and about reports agree that a legitimate business organization exists about the long-term use of these products on vital teeth. In clinical studies, the occurrence of tooth sensitivity is very common with the utilize of these agents, although the cause of these reactions is not known. Bleaching agents will also chemically burn down the gingiva if the agent is not sequestered fairly in the bleaching tray. This is not a problem with a properly constructed tray, and long-term, low-dose effects of peroxides on the gingival and periodontal tissues are not known.

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A Review of Fundamental Ingredients Used in Past and Present Auto-Dishwashing Formulations and the Physico-Chemical Processes They Facilitate

Alan Tomlinson , Joseph Carnali , in Handbook for Cleaning/Decontamination of Surfaces, 2007

iv.4.2.3. Catalyzed systems

Bleach catalysts form the third class of non-chlorinated bleaches. Catalysts based on manganese [66] and cobalt [67] part by oxidizing, via peroxide or a peracid, to form a bleaching species. To shut the catalytic bicycle, they require the presence of an oxidizable soil and then that they can be reduced back to the starting material. Commonly an optimal catalyst level exists for bleaching – under-dosing results in as well little bleaching species, over-dosing results in rapid peroxide or peracid decomposition leaving nothing to regenerate the goad toward the end of the wash cycle [68]. Generally, bleach performance improves with increasing peroxide or precursor level.

As was the case with bleach activators, many potential bleach catalyst systems have been proposed but never commercialized because of stability issues [69]. The most discussed manganese-based goad is a dinuclear manganese macrocyclic ligand-containing molecule, MnIv 2(μ-O)3 (i,4,7-trimethyl−1,4,seven triazacyclononane)ii (PF6)ii.

This catalyst is capable of working finer with perborate or percarbonate alone, but of form the process works better at pH ten than at pH ix considering of the higher peroxide bleach activity. Manganese levels as low as one–2.5 μM (around ii ppm in the wash) take been found to be effective at effectually 10–l ppm AO. The TAED/perborate system tin be used in the catalytic reaction nether similar weather to perborate lone, but is also limited past the pH requirements for optimal perhydrolysis. The manganese system gives skilful tea destaining and, in contrast to TAED/perborate solitary, shows some ability to enhance starch removal [66].

A cobalt-based goad has as well been proposed for auto dishwashing applications, having the structure [Co (NH3)5 OAc]Cl2. This cobalt-chelated catalyst, cobalt pentaamine acetate chloride, has cobalt in the +3 oxidation country [seventy]. Optimal usage atmospheric condition are ii–x ppm cobalt catalyst in the launder liquor – in the guild of 0.i% of the formulation. This arrangement also works with whatever convenient source of hydrogen peroxide – H2O2 itself, perborate, or percarbonate [71]. Piece of work on cobalt (III) systems appears to be ongoing, with recent patents proposing a range of ligands and claiming compatibility with a broad spectrum of enzymes [72,73].

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BLEACHES AND STERILANTS

M.A. Busch , One thousand.W. Busch , in Encyclopedia of Belittling Science (Second Edition), 2005

Precautions in Handling

Bleaching agents and disinfectants are all strong oxidants that in full-bodied course can react explosively with reductants, including organic affair. Disinfectants are effective considering they are toxic to microorganisms, and in sufficient concentration will produce agin health effects in humans. Chlorine gas, which is commercially available in steel cylinders as a gas over liquid, is a powerful irritant that can crusade fatal pulmonary edema. Inadvertent addition of acid to liquid bleach (NaOCl) causes the release of poisonous Cl ii. While chlorine dioxide dissolved in water is stable (if kept cool and abroad from lite), the gas will detonate at pressures to a higher place 300   Torr. To avert germination of explosive concentrations of ClO2 above the solution, the concentration of chlorine dioxide must be kept beneath 5   g   ClOtwo per liter of H2O. Concentrated solutions of hydrogen peroxide as well react explosively with organic affair.

Training of standard solutions of iodine and the amperometric decision of chlorine in water samples make use of arsenic trioxide (Every bit2O3) or phenylarsine oxide (Chalf dozenH5AsO), respectively, every bit reagents. These titrations generate toxic waste that must be disposed of in an environmentally safe fashion. The price of collecting and disposing of these reagents must exist included in the cost of performing such determinations. Crystal violet is a suspected carcinogen and solutions formed from the leuco crystal violet method should also be treated as toxic waste material.

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Laundry Cleaning of Textiles

James Burckett St. Laurent , ... Lieva van Langenhove , in Handbook for Cleaning/Decontamination of Surfaces, 2007

five.ii.iii. Bleach Activators

Bleach activators are molecules that can course peracids by reaction with hydrogen peroxide, referred to as perhydrolysis, in situ during the wash process, as illustrated in Effigy B.1.I.11. Since the generating perhydrolysis reaction involves the peroxyanion of hydrogen peroxide, bleach activators require college pH than preformed peracids to be constructive [23].

Figure B.i.I.11. Peracid formation through perhydrolysis reaction

Despite on-going intensive research, only three activators accept been commercialised. These include tetraacetylethylene diamine (TAED, Figure B.1.I.12) which is utilised in over 50% of the Western European detergents, nonanoyloxybenzene sulphonate (NOBS, Figure B.i.I.thirteen) which is used in the United States and developing countries [24] and lauryloxybenzene sulphonate (LOBS) which is formulated in Japan and is an analogue of NOBS.

Figure B.1.I.12. Tetraacetylethylene diamine (TAED)

Figure B.one.I.13. Nonanoyloxybenzene sulphonate (NOBS)

On perhydrolysis, ane mole of TAED generates two moles of the peracetic acid anion, a highly hydrophilic peracid anion, and one mole of diacetylethylenediamine. On the other hand, upon perhydrolysis, NOBS generates pernonanoic acid which is a more hydrophobic peracid. The hydrophobic/hydrophilic balance of the peracid dictates the operation and stain selectivity from driving stain removal on hydrophilic stains such every bit java, tea and wine (peracetic acrid) to hydrophobic dinginess stains (pernonanoic acrid). Nevertheless, the NOBS arrangement undergoes an additional reaction that forms diacyl peroxide as a result of the nucleophilic attack of the peracid anion on the NOBS precursor equally shown in Figure B.1.I.14 [25]. This undesirable side-reaction can be minimised past the use of an excess molar quantity of hydrogen peroxide and past the formulation of detergents at higher pH.

Effigy B.1.I.14. Diacyl peroxide formation

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Body dermatitis

Reid A. Waldman MD , Jane Yard. Grant-Kels Physician, FAAD , in Dermatology for the Principal Care Provider, 2022

Other therapies

•

Bleach baths can exist used.

•

Twice-weekly dilute bleach baths (i-half cup of household bleach mixed into a 40-gallon bath of water) have long been recommended to prevent pathologic bacterial growth on patients with AD; however, recent show suggests that routine use of bleach baths is unnecessary.

•

Bleach baths are indicated for patients with recurrent skin and soft tissue bacterial infections or who are known to exist colonized with Staphylococcus aureus.

•

Moisture wraps are used to better both skin hydration and the efficacy of topical corticosteroids.

•

Moisture wraps are very effective for treating severe AD; all the same, compliance is oft poor. Wet wraps should be considered for any patient who has an acute flare that cannot exist managed with traditional topical therapies alone.

•

Written instructions on how to properly perform a wet wrap are available from the National Eczema Association at: https://nationaleczema.org/eczema/treatment/moisture-wrap-therapy/.

•

Phototherapy, pills, and injectables for Advert can be prescribed by a specialist.

•

Patients with affliction that is refractory to topical management and those who nowadays with disease affecting more ten% BSA should be referred to a dermatologist who specializes in the use of phototherapy, systemic medications, or biologics for the handling of AD.

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Cilia, Part A

Ingrid Brust-Mascher , ... Jonathan M. Scholey , in Methods in Enzymology, 2013

4.2 FRAP recordings and interpretation of rate and extent of fluorescence recovery (Fig. 16.5)

Figure xvi.5. Fluorescence recovery after photobleaching (FRAP) analysis of tubulin, TBB-4 dynamics in phasmid sensory cilia. Upper panels: the entire ciliary axonemes of phasmids expressing fluorescent TBB-four (−   i   min) were photobleached (0   min) and their recovery past incorporation of fluorescent tubulin at the tips of the middle and distal segment MTs (arrowheads) was monitored over the subsequent 30   min. Lower panels: FRAP recovery curves for middle (left) and distal (right) segments.

 From Hao, Thein, et al. (2011)
1.

Bleach and image a region of involvement as explained earlier.

2.

Measure the fluorescence intensity in the region of recovery. If the complete bleached region recovers, measure out this region; however, if the recovery region is smaller than the bleached region, mensurate only the recovery region.

3.

Average iii to v measurements before the bleach to obtain the prebleach intensity.

iv.

Normalize all measurements with the prebleach intensity.

5.

Fit the normalized intensity to F(t)   = F 0  +   (F inf  − F 0)   ×   exp(−   ln(ii)t/t one/two). F 0 represents the intensity immediately subsequently the bleach, and its value is 0 for a consummate bleach. F inf represents the final recovered intensity, and its value is 1 for a complete recovery.

six.

The parameter t 1/2 represents the half time of recovery.

vii.

The percentage recovery is calculated as (F inf  − F 0)/(1   − F 0)   ×   100.

8.

If the recovery region is small, line scans can be used to better estimate the percentage recovery. Obtain a line browse on the axoneme before the bleach, immediately after the bleach and later a full recovery. Measure out the maximum intensity in each of the line scans, and summate the percent recovery as (I inf  − I 0)/(I pre  −   I0)   ×   100, where I inf is the terminal intensity after recovery, I pre is the intensity before the bleach, and I 0 is the intensity immediately after the bleach.

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Bleaching

George Freedman , ... Linda Helene Greenwall , in Contemporary Esthetic Dentistry, 2012

In-Function Tooth Whitening with Light Application—"Wet" Technique

The bleach and gauze technique is unlike from the "dry out" gel application in that gauze is kept in a bleach-moistened country on the teeth throughout the handling process. This ensures that the bleaching cloth is continually active in releasing oxygen ions, that active bleaching fabric remains in contact with the tooth surfaces at all times, and that the released oxygen ions accept a decreased ability to escape the immediate proximity of the tooth surface. The bleach and gauze "wet" technique can exist used with most in-office bleaching materials. Treatment modalities are selected according to clinician preference and patient condolement.

The kickoff step in this procedure, as with most in-office bleaching systems, is to polish the surfaces of the teeth to remove all the debris and eliminate whatsoever remaining extrinsic surface stains that have not been locked into the enamel lattices and dentinal tubules. In Figure 14-39, A , the correct central incisor is slightly darker than the other anterior teeth, possibly because of earlier trauma or injury. It is likely to bleach less effectively than the adjacent teeth.

Whatsoever commercially available prophylaxis paste that does non contain fluoride can be used, but increasingly, remineralizing materials containing NovaMin are selected. The facial protective barrier is practical and then the cheek retractor is used to separate the maxillary and mandibular arches, displace the cheeks, and expose the upper and lower inductive teeth for bleaching. Next the gingival barrier is placed in a gel form and light cured to hardness such that information technology is retained on the tissue without adhesives; its physical shape and the undercuts of the gingival areas are adequate to retain the barrier in identify throughout the entire bleaching process (Effigy 14-39, B ).

Cotton rolls may exist applied in the mucosal folds to staunch salivary flow and to keep the operating area dry out. A slow-speed suction should exist at the ready in case excess saliva forms in the patient'due south mouth. The bleaching gel is first applied on the buccal surfaces of the teeth, and and so the bleach-moistened gauze is placed over the first layer of gel (Figure 14-39, C ). The bleaching fabric seeps through the gauze slowly. If information technology is necessary to add more bleaching material to thoroughly wet the gauze, gel is added on the outside surface of the gauze. The clinical image shows 1 gauze on the maxillary teeth and 1 on the mandibular, whitening both arches simultaneously. If the gauzes brainstorm to desiccate, boosted gel is applied on the gauze surface. The bleaching gel penetrates the gauze and may ooze out in some areas. In other areas, the gauze has bereft bleach below information technology to be completely wetted. In these areas, whitening material is added from the outside, either buccal or lingual, to ensure that the gauze is completely moist with bleaching gel.

Although the bleaching gel with the gauze should whiten the teeth effectively, some dentists, and in particular some patients, prefer to have the light-activated protocol used in addition to the chemical reaction of the bleach. The bleaching light is applied to the surface of the gel and the underlying gauze (Effigy 14-39, D ). The objective is to always have excess gel in shut proximity to the tooth. The light activation liberates oxygen ions from the bleach product, breaking down the peroxide (H2Oii) to water (H2O) and oxygen ions (O–). This allows the free oxygen ions or radicals that are close to the tooth surface to penetrate the semi-permeable surface of the enamel and dentin. One time inside the tooth structures, they suspension downwards the double bonds of the long-concatenation stain molecules. The smaller, shorter-chain stain molecules tin can then pass through the semi-permeable layer from the enamel and dentin into the oral crenel, where they are rinsed or washed away.

Many bleach activating lights are available. Some bleach manufacturers recommend proprietary lights, whereas others recommend generic light sources including composite curing lights. For the practitioner the most important clinical consideration is to ensure that the selected lite source does not overheat vital teeth to the point at which painful in-handling discomfort, post-handling sensitivity, or permanent pulpal harm can occur. In the case shown in Figure 14-39, a curing low-cal was used to activate the bleach. Approximately 1 minute of total light-activation time, delivered from the buccal, was judged necessary per tooth. To prevent excessive rut buildup in the teeth, the "wave" technique is recommended. A 20-second application of the activating lite is delivered to one tooth. The operator then moves on to an adjacent tooth for a 20-2nd calorie-free activation, then on, until the entire arch has been activated. Then the operator returns the lite to the first tooth for the 2d 20-second session of calorie-free reactivation of the gel. By this time, the tooth has cooled down from the get-go activation, and over-heating is far less likely. With the "wave" technique the tooth is never immune to estrus up more i° to 2° C over its normal intra-oral temperature. Furthermore, the tip of the activating calorie-free is kept several millimeters abroad from the tooth, gel, and gingival surfaces (at that place should not exist any bodily concrete contact). This prevents the hot tip of the activating light from thermally damaging either the soft or the hard tissues.

The entire procedure of applying the gauze and the bleaching gel (and optionally the activating calorie-free) should be repeated at least iii times to constitute a single bleaching procedure or session.

After the bleaching is complete, the gauze is removed with college pliers and the remaining gel is wiped away with a wet gauze. One time is the remaining gel has been thoroughly eliminated, the gingival barrier tin can exist removed. And then the cheek retractors are taken away, and the facial protection is lifted away. The patient rinses to eliminate whatsoever bleaching gel remaining betwixt the teeth or around the soft tissues. The teeth are now significantly whiter than they were before handling (Figure fourteen-39, E ). Some fall-back in molar coloration tin can be expected to occur over the next 1 to 2 weeks (mostly caused by surface rehydration, not re-staining). The in-role procedure is typically a multi-engagement procedure encompassing two or 3 sessions, with abode bleaching as a highly recommended course of therapy between in-office sessions. This combined in-function and calm regimen offers the best and longest-lasting tooth-whitening results.

The right primal incisor has remained somewhat yellower than the other teeth (Figure 14-39, F and Grand ). Although it is less dark than before, it is however less bleached than the next teeth. Previous trauma or injury probable acquired a narrowing of the lurid chamber to brand this tooth somewhat darker than the others. Information technology is by and large accepted that trauma can crusade internal haemorrhage and circulatory harm within the pulp chamber. Bilirubin deposits from the damaged blood vessels are secreted in diverse layers of the molar structure. Equally the bilirubin ages, it becomes yellower and/or browner, giving the entire tooth a somewhat darker tinge. These bilirubin stains tin be removed, but the procedure may be hard or impossible in many cases. In these situations, bleaching is non an adequate approach and veneers or crowns are indicated.

Before bleaching, the incisal composite restoration on the left central incisor was relatively well color matched to the residue of the molar (despite the visible margin). After bleaching, the restoration is far less color matched and has get an esthetic liability. Thus it is important to note that patients who accept visible, merely colour-matched, anterior restorations must be warned that these restorations are likely to require replacement afterward bleaching to match the whitened coloration of the teeth. Typically the replacement of quondam restorations should non embark until at to the lowest degree 1 to two weeks after the bleaching procedure has been completed; the variable fall-dorsum (to darker coloration with in-office procedures) or continuation (to whiter coloration with at-habitation procedures) that occurs later on the finish of the bleaching treatment is rather unpredictable. These post-treatment color changes often alter tooth shade significantly in the days immediately later on bleaching. After most 2 weeks, the rehydration or de-staining of the teeth is consummate, and tooth coloration becomes quite stable, irresolute only equally a direct result of normal intra-oral staining.

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